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CIRS Auditorium ventilation system : adequacy assessment, energy consumption and comfort of the living… Tabet, Marc Apr 30, 2012

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UBC Social Ecological Economic Development Studies (SEEDS) Student Report        CIRS Auditorium Ventilation System: Adequacy Assessment, Energy Consumption and Comfort of the Living Space Provided Prepared by: Marc Tabet  University of British Columbia CEEN 596 April 30, 2012           Disclaimer: “UBC SEEDS provides students with the opportunity to share the findings of their studies, as well as their opinions, conclusions and recommendations with the UBC community. The reader should bear in mind that this is a student project/report and is not an official document of UBC. Furthermore readers should bear in mind that these reports may not reflect the current status of activities at UBC. We urge you to contact the research persons mentioned in a report or the SEEDS Coordinator about the current status of the subject matter of a project/report”. CEEN 596 FINAL PROJECT REPORT CIRS Auditorium Ventilation  System:Adequacy Assessment, Energy Consumption and Comfort  of the Living Space ProvidedPrepared by: Marc TabetApril 30, 2012 Page 1/74Table of ContentsAppendices List..........................................................................................................................................4Preface........................................................................................................................................................7Acknowledgments......................................................................................................................................7Executive Summary....................................................................................................................................8a) Project Structure...............................................................................................................................8b) Important Findings............................................................................................................................8I- Introduction..........................................................................................................................................11a) Purpose and Objectives...................................................................................................................11b) Background.....................................................................................................................................12II- Systems Description and Control Strategy...........................................................................................13a) The Ventilation System....................................................................................................................13General Description .......................................................................................................................13Characteristic Components............................................................................................................14Available Sensors............................................................................................................................15b) The Ventilated System.....................................................................................................................17General Description .......................................................................................................................17Space Occupancy/Usage.................................................................................................................18Available Sensors............................................................................................................................20c) The Control Strategy........................................................................................................................22III- Data and Methodology.......................................................................................................................24a) Experimentation Planning...............................................................................................................24Table 09: Experimentation Protocol....................................................................................................25Table 10: Experimentation Protocol Continued..................................................................................26b) Ventilation Rates and Air Change....................................................................................................27Ventilation.......................................................................................................................................27Air Change Assessment Using The CO2 Concentration Equilibrium Point Methodology..............28Air Change Assessment Using a Tracer Gas Methodology ............................................................28c) Energy Consumption.......................................................................................................................30The Fans..........................................................................................................................................30Heating of the Air............................................................................................................................30Heat Recovery.................................................................................................................................31d) Air Quality Assessment...................................................................................................................32 Volatile Organic Compounds Concentration [VOCs]:....................................................................32Carbon Dioxide Concentration [CO2]:............................................................................................34e)Thermal Comfort  Assessment ........................................................................................................35IV- Data Interpretation and Analysis – Results.........................................................................................36a) Experimentation Outcome: Actual Occurrence and Obstacles Encountered.................................36b) Ventilation Rates Assessment Results.............................................................................................38Ventilation.......................................................................................................................................38Air Change Assessment Using The CO2 Concentration Equilibrium Point Methodology..............40Air Change Assessment Using a Tracer Gas Decay Methodology ..................................................41c) Energy Consumption.......................................................................................................................46 Page 2/74The Fans..........................................................................................................................................53Heating of the Air............................................................................................................................53Heat Recovery.................................................................................................................................53d) Air Quality Assessment Results and Limitations.............................................................................54 Volatile Organic Compounds Concentration [VOCs].....................................................................54Carbon Dioxide Concentration [CO2] ............................................................................................58e) Thermal Comfort  Assessment Results and Limitations..................................................................62V- Results Integration, Energy Savings and Optimization Recommendations.........................................65VI- Conclusion...........................................................................................................................................71VII- Project Significance............................................................................................................................71VIII- References........................................................................................................................................72IX- Appendices .........................................................................................................................................73Index of Tables  Table 00: Acronyms and Abbreviations....................................................................................................6  ..................................................................................................................................................................6Table 01: List of the AHU2 Characteristic Components...........................................................................14Table 02: List of The AHU of the Auditorium Sensors Used to Extract Data For This Study....................15Table 03: List of The AHU of the Auditorium Sensors Not Used to Extract Data For This Study.............16Table 04: CIRS Auditorium Class Schedule and Expected Occupancy......................................................19Table 05: Auditorium Maximum Fresh Air Supply Requirements and Needs..........................................20Table 06: Auditorium Average Fresh Air Supply Requirements and Needs.............................................20Table 07: List of Auditorium Sensors Used to Extract Data For This Study..............................................21Table 08: List of Auditorium Sensors Not Used to Extract Data For This Study.......................................21Table 09: Experimentation Protocol.........................................................................................................25Table 10: Experimentation Protocol Continued.......................................................................................26Table 11: Experimentation Placement, Protocol and Obstacles Encountered........................................37Table 12: OA, EA, SA Manual Measurements Results..............................................................................39Table 13: Outside Air Flow Intake Assessment Using Two Different Techniques.....................................39Table 14: CO2 Concentration Equilibrium Methodology for OA Flow Assessment Results.....................40Table 15: CO2 purchase for the Tracer Gas Decay Methodology Costs ..................................................41Table 16: ACR Assessment Results through [CO2] Decay Monitoring Methodology..............................45Table 17: Numerical Energy Absolute Value Analysis for Test Period 2...................................................48Table 18: Numerical Energy Deviation Percentage From Average Analysis for Test Period 2..................49Table 19: Numerical Absolute VOC Concentrations Level Analysis For Test Period 2..............................54Table 20: Numerical Absolute CO2 Concentrations Level Analysis For Test Period 2..............................60Table 21:  Thermal Comfort Assessment Over Testing Period ................................................................62Table 22: Thermal Comfort Uniformity Within The Auditorium Analysis................................................63Table 23: Experiments Outcome Summary 1...........................................................................................68Table 24: Experiments Outcome Summary 2...........................................................................................69 Page 3/74List of FiguresFigure 01: Auditorium Ventilation System BMS Screen-shot - Sensors Layout.......................................17Figure 02: Auditorium BMS Screen-shot - Sensors Layout......................................................................22Figure 03: Thermodynamic CV 1st Law Analysis on Supply Air ..............................................................30Figure 04: Thermodynamic Model of The Heat Recovery Unit...............................................................31Figure 05a: Detectable VOCs....................................................................................................................33Figure 05b: Correlation of CO2 and VOCs Concentrations as Measured in a Typical conference Room.34 Figure 06: ASHRAE Standard 55-2004 Comfort Psychometric Chart......................................................35Figure 07: CO2 Concentration Decay Experiment Explained...................................................................42Figure 08: Overview of CO2 Concentration Decay Over Experimentation Period...................................43Figure 09: Forced CO2 Concentration Decay Monitoring Over 10min and 30min Period.......................44Figure 10: Natural CO2 Concentration Decay Monitoring Over a 45min Period.....................................44Figure 11: Stratification of the Air in the Auditorium Explanation .........................................................46Figure 12: Typical AHU2's Energy Consumption Behavior – Reference Experiment March 5.................47Figure 13: Typical Auditorium Environment VOCs Concentration Behavior – Ref. Exp. March 5............54Figure 14: Typical Auditorium Environment CO2 Concentration Behavior – Ref. Exp. March 5..............59Figure 15: CIRS Energy System Diagram...................................................................................................65Figure 16: Ventilation System Energy Diagram........................................................................................66Appendices List• Appendix_1_Flow_Meter_User_Manual_ABB ACG550 PCR.pdf• Appendix_2_ VOC_Sensor_Greystone Air 300.pdf• Appendix_3_ Honeywell_Temperaturre_C70xx sensors.pdf• Appendix_4_ Honeywell_CO2_sensor_C7632.pdf• Appendix_5_ Honeywell Humidity H763x.pdf• Appendix_6_ Honeywell Press P7640.pdf• Appendix_7_ UltraTech Air Flow Stations EDPTjr OM.pdf• Appendix_8_ AHU_Specifications.pdf• Appendix_10- Honeywell TR21_TR24 temp sensor.pdf• Appendix_12- AHU2_Sequence_of_Operation.pdf• Appendix_13_Image_Auditorium.jpg• Appendix_14_Image_Auditorium.jpg• Appendix_15_Image_Auditorium.jpg• Appendix_16_Image_Auditorium.jpg• Appendix_17_Image_Auditorium.jpg• Appendix_18_Image_Auditorium.jpg• Appendix_19_Image_Auditorium.jpg• Appendix_20_Image_Auditorium.jpg• Appendix_21_Image_Auditorium.jpg• Appendix_22_Image_Auditorium.jpg• Appendix_23_Image_Auditorium.jpg• Appendix_24_ A-101 - Floor Plan Level Ground.pdf Page 4/74• Appendix_25  Understanding How to Calculate Enthalpy of Moist Air.pdf• Appendix_26_Experiment_1_Test_Period_1_9am_to_4pm_Results.pdf• Appendix_27_Experiment_1_Test_Period_1_All_Day_Results.pdf• Appendix_28_Experiment_2_Test_Period_1_9am_to_4pm_Results.pdf• Appendix_29_Experiment_2_Test_Period_1_All_Day_Results.pdf• Appendix_30_Experiment_3_Test_Period_1_9am_to_4pm_Results.pdf• Appendix_31_Experiment_3_Test_Period_1_All_Day_Results.pdf• Appendix_32_Experiment_4_Test_Period_1_9am_to_4pm_Results.pdf• Appendix_33_Experiment_4_Test_Period_1_All_Day_Results.pdf• Appendix_34_Experiment_5_Test_Period_1_9am_to_4pm_Results.pdf• Appendix_35_Experiment_5_Test_Period_1_All_Day_Results.pdf• Appendix_36_Experiment_6_Test_Period_1_9am_to_4pm_Results.pdf• Appendix_37_Experiment_6_Test_Period_1_All_Day_Results.pdf• Appendix_38_Experiment_7_Test_Period_1_9am_to_4pm_Results.pdf• Appendix_39_Experiment_7_Test_Period_1_All_Day_Results.pdf• Appendix_40_Experiments_Comparison_Absolute_Trial_1.pdf• Appendix_41_Experiments_Comparison_Relative_Trial_1.pdf• Appendix_42_Experiment_1_Test_Period_2_Results_9am_to_4pm.pdf• Appendix_43_Experiment_1_Test_Period_2_Results_All_Day.pdf• Appendix_44_Experiment_2_Test_Period_2_Results_9am_to_4pm.pdf• Appendix_45_Experiment_2_Test_Period_2_Results_All_Day.pdf• Appendix_46_Experiment_3_Test_Period_2_Results_9am_to_4pm.pdf• Appendix_47_Experiment_3_Test_Period_2_Results_All_Day.pdf• Appendix_48_Experiment_4_Test_Period_2_Results_9am_to_4pm.pdf• Appendix_49_Experiment_4_Test_Period_2_Results_All_Day.pdf• Appendix_50_Experiment_5_Test_Period_2_Results_9am_to_4pm.pdf• Appendix_51_Experiment_5_Test_Period_2_Results_All_Day.pdf• Appendix_52_Experiment_6_Test_Period_2_Results_9am_to_4pm.pdf• Appendix_53_Experiment_6_Test_Period_2_Results_All_Day.pdf• Appendix_54_Experiment_7_Test_Period_2_Results_9am_to_4pm.pdf• Appendix_55_Experiment_7_Test_Period_2_Results_All_Day.pdf• Appendix_56_Experiments_Comparison_Absolute_Trial_2.pdf• Appendix_57_Experiments_Comparison_Relative_Trial_2.pdfAppendix_58_Automatic_Day_1_Results_9am_to_4pm.pdf• Appendix_59_Automatic_Day_1_Results_All_Day.pdf• Appendix_60_Automatic_Day_2_Results_9am_to_4pm.pdf• Appendix_61_Automatic_Day_2_Results_All_Day.pdf• Appendix_62_Automatic_Day_3_Results_9am_to_4pm.pdf• Appendix_63_Automatic_Day_3_Results_All_Day.pdf• Appendix_64_Automatic_Day_4_Results_9am_to_4pm.pdf• Appendix_65_Automatic_Day_4_Results_All_Day.pdf• Appendix_66_Automatic_Day_5_Results_9am_to_4pm.pdf• Appendix_67_Automatic_Day_5_Results_All_Day.pdf• Appendix_68_Auto_Day_Results_2_Comparison.pdf Page 5/74Table 00: Acronyms and Abbreviations Page 6/74Table of Abbreviations and AcronymsAbbreviation Unabridged Expression[CO2] Carbon Dioxide Concentration[VOCs] Volatile Organic Compounds ConcentrationAHU Air Handling UnitASHRAEBASE Building Assessment Survey and EvaluationC ConcentrationCIRS Center for Interactive Research on SustainabilityCO2 Carbon DioxideD Impeller DiameterEA Exhaust AirEOS Earth and Ocean SciencesCO2 Emission Volume Flow Rate Per Personh EnthalpyHC Heating CoilHCP Heating Coil PumpHRU Heat Recovery UnitHz HertzI Current Kg Kilogramsl Slope of Linear Regression LineL Liter(s)m mass Mass Flow RateMA Mixed AirNE North-EastNW North-WestOA Outside AirP Supply PressurePF Power Factorppm parts per mill ionQ Flow RateQ (in schematics) Heat RA Return AirRF Return FanRH Relative Humiditys secondsSA Supply AirSBS Sick Building SyndromeSE South-EastSF Supply FanSW South-WestT TemperatureT timeV Voltage (Contextual)V Volume (Contextual)VFD Variable Frequency DriveVOCs Volatile Organic CompoundsDensityx (in certain equations) QualityAmerican Society of Heating, Refrigeration and Air Conditioning Engineers Gpṁρ PrefaceIn the context of my Masters in Clean Energy Engineering Program at UBC I was assigned the final  project of assessing the ventilation system of the auditorium of one of the buildings on campus. The assessment is concerned with the livability of the environment presented by this auditorium and how it relates to the energy consumption of the ventilation system supporting it. Energy conservation and demand  side  management  are  among  our  most  important  tasks  and  objectives  as  clean  energy engineers.  A ventilation system can consume around 1/3 of  a  building's  total   energy needs and seeking its optimization falls directly in the category of energy conservation. The building concerned with the project is the Center for Interactive Research on Sustainability (CIRS),  I  am honored to be granted the opportunity to work on one of the most sustainable and innovative buildings ever created in North America. The main problematic that arises is that,  very often, changes implemented in a ventilation system leading to energy savings are made at the expense of the livability of the environment being  served by this system. The reason for this is that energy is invested through the system into deviating the occupied space conditions away from the ambient ones (often unfavorable for comfortable living, occupation  and activity) to make it more adequate for living. Investing less energy into the process  often results in ambient conditions being counteracted with less intensity.The project is very instructive on many levels and is representative of professional engineering work; it  also covers many type of activities:  data gathering,  in site visits,  coordination with other professionals, the use of a BMS, the gathering of knowledge to interpret the data,  the development of tools  (excel  macros)  to process the data.  It  gives  a  good insight  on the behavior  of  a  ventilation systems in terms of energy consumption and maintaining the comfort of the living space, it also gives good understanding  of  building  living  space management:  what  happens  in  the  background of  a building we use that we are most of the time not aware of. The project is definitely relevant to the objectives of this masters in terms of learning since it is  a direct exposure to energy management. It clearly highlights the advantages and the potential of  having so many sensors on site among which monitoring and optimization. Acknowledgments I am extremely grateful towards all the amazing people, academics, staff and supervisors that have provided me with invaluable support and guidance during this project: Scott Yonkmann, Jen Crothers, Carla Dasilva, Brenda Sawada, Alberto Cayuela, Eric Mazzi, Steven Rogak and all the others I might have unwillingly failed to mention. Page 7/74Executive SummaryThe project has several purposes that will be further elaborated along the report, but mainly,  providing  an  insight  on  an  innovative  ventilation  system  and  the  usefulness  of  the  numerous sensors/controls its is equipped with; as well as to shed the light on how these can be used to reduce  the system's energy consumption while not hindering its adequate function. a) Project StructureThe first part of the project consists of thoroughly understanding and describing the system (both ventilated and ventilating) through the different sections provided and supported by numerous appendices. The second part investigates the theory behind comfortable living conditions at two levels (thermal comfort and air quality) and how it can be measured through the available sensors. The third part  aims  at  establishing  a  relevant  testing  protocol  that  will  make  use  of  the  different  controls available in the system to try to achieve some energy savings through behavior modification. The fourth part consist in executing the protocol and extract the data from the relevant sensors. The fifth part  consist  of  processing and analyzing the data in order to establish a relation between energy consumption and comfortable living conditions  provided by the ventilation system using different tools and engineering knowledge. Finally, the different parts of the analysis are integrated in order to support  suggestions  about  potential  energy  measures.   Along the project  a  set  of  6  experiments compared to a reference day were performed and their results analyzed. b) Important Findings• In  comparison  to  other  commonly  found  building's  ventilation  system the  availability  and variety of the sensors can be deemed excellent. • A relative humidity and temperature  sensors should be installed at the exit of AHU1.• A relative humidity sensor should be installed at the level of the 1st filter of the Heat Recovery Unit.• To  Date  The  OA  and  EA  Flow  Sensors  are  Uncalibrated,  Insure  the  devices  are  properly calibrated in the future.• The  heating  valve  position  sensor  does  not  seem  to  be  reliable  an  investigations  is  recommended to shed light on the matter.• Following Ashrae 62 Standards, the outside air requirement for a maximum occupancy of the auditorium is calculated to be 3408 L/s. • Three methodologies were relied upon to verify if this criterion is met (Manual Measurements in  substitution for  the OA sensor -  CO2 Equilibrium Methodology -  CO2 Decay Monitoring  Methodology).  Page 8/74• The  Manual  Measurements  were  not  reliable  due  to  the  lack  of  ability  to  perform measurements according to standardized protocols.• The CO2 decay monitoring methodology was not reliable due to the very short period of time of testing however both the methodology and the results were presented as reference for potential other studies. • The CO2 equilibrium despite inconsistencies for two experiments showed that the Fresh air intake requirement criterion is met. • When it comes to comparing the experiments to a normal day of operation such as on March 19  it  is  noticed  that  in  all  experiments  during  which  energy  saving  measures  were implemented, the ventilation system's average power consumption is indeed lower.• The energy recovered from the EA of AHU2 at the level of the HRU could not be calculated due to the absence of a proper real time monitoring of the EA flow (uncalibrated sensor).• No  standards  have  been  set  for  VOCs  in  non  industrial  settings.  In  fact,  a  recent  review concluded that no scientifically valid guidance could be given with respect to indoor TVOC levels. There are, however, possible benefits to be derived from keeping exposures to airborne contaminants “As Low As Reasonably Achievable.”• The VOCs concentration seems unexpectedly independent of the auditorium occupation level  during the testing period. An investigation should be made to explain the situation.• Critical Levels of VOCs concentration are never reached when the auditorium is occupied.• VOCs levels are pretty stable along the day, no significant fluctuations are recorded.• A VOCs concentration surge is recorded everyday during the start-up of the ventilation system that last for one to two hours. Potential exposure of students to above the critical limit of VOC concentration can occur at this moment but is not necessarily dangerous/problematic.• The critical CO2 concentration for the auditorium is considered to be 1000 ppm. This arbitrary value comes from the wide belief in building management that this  is  a common practice supported by Ashrae.  The CO2 level  of 1000 is a guideline for comfort acceptability,  not a ceiling value for air quality, it is used as a surrogate for odor causing compounds from human activity that may not be acceptable for human comfort. Page 9/74• A narrow definition of thermal comfort was adopted, an analysis based on this criterion shows that thermal comfort is achieved within the auditorium (despite slight deviations) but overall it would be recommended to increase the temperature set point by 1 degree Celsius.• The integration of all the results obtained in this study show that, a lower energy consumption is achieved, when implementing measures through an override of the control system (such as OA intake reduction or circulation flow reduction), in comparison to a normal day of operation. Some of these measures do not affect significantly the livability of the environment which proves that there is still margin of optimizing the ventilation system operation. • Tweaking the control algorithm of the ventilation system in a way to obtain 10% less circulation flow is recommended. This measure will not hinder the livability/comfort of the auditorium's environment.   Page 10/74I- Introductiona) Purpose and ObjectivesThe purpose of  this  study is  to monitor the state of  several  parameters characterizing the ventilation system of the CIRS Auditorium, process the data gathered, and analyze it  in order to have a better understanding of its behavior and associated energy usage. This would be helpful in providing insights into ventilation needs for auditoriums which are a common application and help develop a protocol for future investigations of the ventilation throughout the CIRS building.            The characteristics of the ventilation includes flow rates of intake, outlet and return air and the achieved  air  renewal  bounded  by  certain  thermal  comfort  and  air  quality  requirements.  The implications of comfortable (thermal and air quality) living space can be infinite and the thorough analysis of each of its contributing factors could encompass a series of research and final projects. This  is the reason why, in the scope of this study, a less thorough definition of what is implied by thermal  comfort as well as air quality will be considered. The metrics involved and their interpretation will be significant  while  not  absolute,  they  include:  temperature,  VOCs  and  CO2 concentrations,  relative humidity  and air  renewal  rate.  When it  comes to assessing the ventilation system: air  flow rates (intake,  outlet  and  return)  and  motors  fan  power  consumption  will  be  monitored.  Those  will  be obtained by data extraction from the already installed sensors.The objectives of this CEEN 596 project will include:• A  description  of  the  CIRS  Auditorium  System: size,  layout,  ventilation  system,  in-situ instruments, occupancy/usage.• A monitoring of the parameters of interest for both the ventilation system and living space provided over a 5 days period during which the former is set on automatic mode.• A series of experiments consisting of overriding the automatic control of the ventilation system parameters such as flow rate and fresh air intake in order to gain an understanding of the ventilation system behavior in the given operating conditions (occupancy and environment).• An estimate of the ventilation energy usage.• An hourly data collection during two distinctive 7 days period in the week of February 6 and March 5. • An air change assessment using a tracer gas methodology (CO2).• An evaluation of the thermal comfort (constrained definition) achieved .• An evaluation of the indoor air quality (constrained definition) achieved. Page 11/74b) BackgroundThe CIRS building in the UBC campus is one of the greenest building on earth. It encompasses a series of  new technologies  to efficiently  provide a comfortable and functional  living space for  its  occupant  thus  reducing  its  impact  on  the  environment  with  which  it  interacts.  The  building  was designed  in  accordance  with  the  highest  standards  of  sustainability.  It  is  meant  to  be  a  living laboratory, in a way that,  it will provide through the different sensors it presents an extensive amount  of data that will enable those interested to understand what are the energy implications of providing a sustainable and functional living space in the buildings of tomorrow. In order to achieve its design  purpose the building should perform well  through all  of  its systems, among which the ventilation system, that contribute to creating this comfortable living space. “Actually, people spend over 80% of their  time indoor.  In most circumstances,  poor  ventilation is  the dominant factor  in causing poor indoor air quality” [1]. Rapidly increasing energy prices, concerns about resource depletion and climate change, and calls for national energy self-sufficiency have concentrated people’s minds on the role energy plays in life [2]. In the future, more buildings will have to be constructed to accommodate the world's growing population. This has to be done with the limited availability of resources in mind. However, s ince old buildings are only replaced with new ones at a very slow rate, it is important to consider how energy is  used in the already existing buildings. It is estimated that buildings could save 10-15 percent on their  energy bills if they witness energy efficiency improvements [2]. Baring in mind that buildings account for  more than 40% of  all  the energy consumption in most countries  [3], all  what have been said reveals the importance of the efficient use of energy in buildings and the information the CIRS will provide with this regard. The living space provided by a room is affected by its level of occupancy and its interaction with the environment. A ventilation system is aimed at replacing the progressively altered air in the room with fresh air (adequate in both temperature and composition). The higher the occupancy of the living space and its thermodynamic contrast with the environment the more artificially altered air has  to be forced in. This requires more energy input into both the modification of the thermodynamic  state of the air (cooling/heating, humidifying/dehumidifying) and the channeling of a greater quantity of it into the room. To which extent this replacement has to be done is dictated by the conditions of  thermal comfort and air quality aimed to be achieved in the room. This represents the relationship between a ventilation system and the building energy usage.  A mechanical ventilation system, in a conventional building, consumes 1/3 to 1/2 of all its energy requirements, and a significant portion of this energy is used for conditioning outdoor air [4,5] which justifies any interest that would be granted to it in the context of this Masters In Clean Energy Program; specially in the case of the CIRS where the ventilation is aimed to be in accordance with the highest sustainability standards. By sustainable living space it is partially implied comfort provided at the least energy cost. This is mostly what is aimed at being assessed through the completion of this project. Given the complexity of the building and the time restrictions imposed it was chosen that a “sample living space” provided by the building will be  evaluated in the scope of this project.  Page 12/74The auditorium of the CIRS was chosen as the “sample living space” of interest for several reasons: • It is a system of which boundaries are clearly and physically defined (isolated from the rest of  the building).• Its high occupancy can make the data obtained more relevant since the study is in big part concerned by how the created environment is perceived.• It represents a significant chunk of the living space provided by the building.• It has a significant amount of sensors monitoring its state.• It has a mechanical ventilation (Air handling unit) system for itself. The study can also be considered a precursor in the assessment of the other parts of the building with  regards to ventilation.II- Systems Description and Control Strategya) The Ventilation SystemGeneral Description The ventilation system of the CIRS auditorium serves one temperature control zone through a single duct air distribution system; it is referred to as central single zone system. Although there might be some ambiguities with regards to this matter, because of the fact that the fans are regulated by VFDs, the system can be regarded as a  constant volume system. The flow rates were noticed to be constant (SA flow rate is around 3000 L/s) except when VOCs concentration reached critical values, as can be seen on March 21 (Appendices 62 and 63).  The speed variation of the fans is mostly required  for their start up sequence and to maintain the static pressure within the duct to a desired one.  The  start up sequence reduces the load on the fan motors by progressively increasing their speed to the desired steady state one. In theory the VFD can be manually controlled in order for the fans to reach  any desired RPM. This opportunity is exploited in the experimentation part of this study and can be  the  source  of  energy  savings.  The  system comprises  a  return  fan  and a heat  recovery  system to preheat the outlet air drawn in with the room exhaust air. The outdoor air intake control is regulated through the positioning of the supply, return and outlet dampers which is regulated according to the VOCs and CO2 concentration in the auditorium. Figure 1 can help the reader visualize the system. Page 13/74Characteristic ComponentsThis section gives an overview of the main components that make up the ventilation system and some of their specifications. The purpose of it is to give an insight on the design intents as well as  the size of the system which would potentially enable a comparison to other similar systems in other buildings if needed.List of the AHU2 Characteristic Components (Appendix 8, Appendix 9)Components Characteristics QuantificationSupply Fan Qty - Max Air-FLow, BHP, Diameter 3X - 4945, 12.64, 20”Return Fan Qty - Max Air-FLow, BHP, Diameter 3X – 10000,2.18, 16”Supply Fan Motor Qty - Voltage, Phases, Capacity 3X - 575V,   3phases,        5HPReturn Fan Motor Qty - Voltage, Phases, Capacity 3X - 575V,   3phases,        5HPFilter 1 Type, Quantity, Surface Area Pleated, 8, 24" x 24"Filter 2 Type, Quantity, Surface Area Air-screen  2300  electronic,  8,  4 24"x24" & 4 24"x12"OA Damper Number  of  Blades,  Surface  Area, Parallel/Opposed7 Blades,  1881 square inches,  Parallel bladeMA Damper Number  of  Blades,  Surface  Area, Parallel/Opposed8  Blades,1677  square  inces,  Opposed bladeEA Damper Number  of  Blades,  Surface  Area, Parallel/Opposed8  Blades,1677  square  inces,  Opposed bladeCooling Coil Max Coolant Flow Rate,  Surface Area, Coolant Fluid Temperature...90.5GPM, 30sqft, 50F...Heating Coil Max  Heating Fluid  Flow Rate,  Surface Area, Fluid Temperature...116.5GPM, 30sqft, 110F...Duct-work Section Area 1, Length 1, Section Area 2, Length 2...Appendix 9Air Outlets Numbers, Types, Surface Area Appendix 9Air Inlets Numbers, Types, Surface Area Appendix 9Table 01: List of the AHU2 Characteristic Components Page 14/74Available SensorsThe ventilation system of the CIRS auditorium is equipped with a variety of sensors monitoring the state of its variables of which some are directly measurable (such as temperature) and some are derived (such as flow rate or energy consumption). In comparison to other commonly found building's ventilation system the availability and variety of the sensors can be deemed excellent. This greatly facilitates  any  study  aimed  at  understanding  the  behavior  of  the  system,  the  process  of troubleshooting any defect in the context of a maintenance procedure or simply insuring a proper functioning of  the system. The information provided by those sensors is  ,  with a few exceptions, enough  (if  no  obstacles  are  encountered,  such  as  misconfiguration  or  defects)  to  support  the completion of the objectives of this project without requiring additional monitoring through manual  measurements.  However  this  information  is  not  “ultimate”in  a  way that,  in  the  context  of  other studies, other measurements might be needed. For example such as in the context of an air-balance study, a noise adequacy study or a vibration study etc...  List of The Auditorium AHU Sensors Used For Data ExtractionSensor Brand Model Reference Additional InfoOA Flow Rate UltraTech EDPTjr Appendix 7MA Temperature Honeywell C7041R2018 Appendix 3SF Speed ABB ACH550-VDR-017A-6+F267 Appendix 1SF Current Consumption ABB ACH550-VDR-017A-6+F267 Appendix 1SA  Temperature Honeywell C7041R2003 Appendix 3SA Relative Humidity Honeywell H7635B2018 Appendix 5SA Flow Rate UltraTech EDPTjr Contact ManufacturerSA Static Pressure Honeywell P7640B1032 Appendix 6SA Pressure Honeywell P7640B1032 Appendix 6RF Speed ABB ACH550-VDR-017A-6+F267 Appendix  1RF Current Consumption ABB ACH550-VDR-017A-6+F267 Appendix 1RA CO2 Concentration Honeywell C7632B Appendix 4RA VOC Concentration* Greystone Air Appendix 2RA Relative Humidity Honeywell H7635B2018 Appendix 5RA Temperature Honeywell C7041R2003 Appendix 3EA Flow Rate UltraTech EDPTjr Appendix 7EA Temperature Honeywell C7041R2003 Appendix 3Table 02: List of The AHU of the Auditorium Sensors Used to Extract Data For This Study*  More  information  with  regards  to  the  sensor's  operating  principle,  resolution  and  detectable  compounds  is  given  in  the  VOCs  Concentration related sections Page 15/74List of The Auditorium AHU Sensors Not Used For Data ExtractionSensor Sensor SensorHeating Valve Opening SF (Supply Fan) Speed OA Damper OpeningHeating Pump Control SA Static Pressure RA Damper OpeningHeating Pump Current ConsumptionRF (Return Fan) Speed EA Damper OpeningCooling Valve Control RF Current Consumption SA PressureTable 03: List of The AHU of the Auditorium Sensors Not Used to Extract Data For This StudyNote:  An  example  on  the  limitations  of  this  selection  of  sensors  was  encountered  while performing this  study.  One can deem useful  the knowledge  of  energy (from each  of  the two air handling units ) being exhausted prior to recovery which is of interest. To do so, an as can be seen in the heat  recovery section of  this  report,  a  knowledge of  the flow rate,  temperature and relative humidity is needed for each of the relevant air  streams. While there is a sensor in the system to quantify the amount of energy extracted from the combined streams of the two air handling units of  the  building  some  sensors  are  lacking  thus  preventing  the  derivation  of  the  amount  of  energy escaping from the air handler one or the amount of energy extracted from each stream individually. To counter this problem, two relative humidity and temperature sensors were installed one at the level the the air handler one exhaust stream and the other at the level of the mixing of the two streams. Page 16/74Figure 01: Auditorium Ventilation System BMS Screen-shot - Sensors Layoutb) The Ventilated SystemGeneral Description The ventilated system is an approximately 465m2  space with 426 seats arranged in successive arc-circles. With an average height roughly  measured, the volume is estimated to be around 3240m3. Sensors are mounted on the side walls at all corners of the auditorium. The supply of air is mainly directed from East to West: most of the air is supplied by the vents under the seats and at the top  back of  the auditorium. Most of  the return air  is  channeled from the front through big  elevated squared vents. The auditorium present four windows on its roof that open parallel to the ground and prevent  rain  from leaking  in  when  opened  thanks  to  an  ingenious  design.  Appendices  13  to  24 describe in images and drawings what could hardly be described in words. Page 17/74Space Occupancy/UsageThe adequacy of the living space provided by the auditorium through it's ventilation system is intricately related to its occupation level. The occupants alter the living space by emitting CO2, VOCs and Heat which the ventilation systems permanently tries to keep within reasonable ranges as defined by the relevant standards. How the environment is perceived by the occupants will be dependent on how many  occupants  there  is;  and  therefore  the  adequacy  of  the  ventilation  system should  be assessed for different occupation levels and should be deemed reasonable for all of them.  There are more than 4 classes during each working day and usually attended by more than 150 Students. The UBC  Classroom  Services  was  contacted  to  obtain  a  detailed  schedule  describing  the  expected occupancy level of the auditorium during the hours of interest (9am to 4pm during working days). The  schedule is presented in Table 04. Page 18/74CIRS Auditorium Class Schedule/OccupancyFrom To Monday Tuesday Wednesday Thursday Friday09:00 09:30 PSYC 102Section 002Christie, StellaOccupancy:133PSYC 102Section 002Christie, StellaOccupancy:133PSYC 102Section 002Christie, StellaOccupancy:13309:30 10:00 PSYC 101Section 007Rankin, CatherineOccupancy:255PSYC 101Section 007Rankin, CatherineOccupancy:25510:00 10:30 PSYC 102Section 003Christie, StellaOccupancy:257PSYC 102Section 003Christie, StellaOccupancy:257PSYC 102Section 003Christie, StellaOccupancy:25710:30 11:0011:00 11:30 PSYC 208Section 003Wehr, PaulOccupancy:202PSYC 209ASection 002Handy, ToddOccupancy:227PSYC 208Section 003Wehr, PaulOccupancy:202PSYC 209ASection 002Handy, ToddOccupancy:227PSYC 208Section 003Wehr, PaulOccupancy:20211:30 12:0012:00 12:30 PSYC 102Section 004Paulhus, DelroyOccupancy:336PSYC 102Section 004Paulhus, DelroyOccupancy:336PSYC 102Section 004Paulhus, DelroyOccupancy:33612:30 13:00 ENDS 231Section 001Van Duzer, LeslieOccupancy:14913:00 13:30 PSYC 100Section 002Rawn, CatherineOccupancy:371PSYC 100Section 002Rawn, CatherineOccupancy:371PSYC 100Section 002Rawn, CatherineOccupancy:37113:30 14:0014:00 14:30 PSYC 102Section 005Paulhus, DelroyOccupancy:135PSYC 102Section 006Klonsky, DavidOccupancy:316PSYC 102Section 005Paulhus, DelroyOccupancy:135PSYC 102Section 006Klonsky, DavidOccupancy:316PSYC 102Section 005Paulhus, DelroyOccupancy:13514:30 15:0015:00 15:30 CIVIL 21Section T2ALaval, BernardOccupancy:10315:30 16:0016:00 16:3016:30 17:00Table 04: CIRS Auditorium Class Schedule and Expected Occupancy Page 19/74Auditorium Maximum Fresh Air Supply Requirements and NeedsActivity Type Surface Area Maximum Occupancy Maximum Outdoor Air Requirement [m2] [people] [people/100 m2] [L/s-person] L/s- m2For the CIRS Auditorium at Max Occupancy [L/s]- People CriterionFor the CIRS Auditorium Independently of Occupancy [L/s] – Area CriterionAuditorium 465 426 92 8 12 3408 5580Table 05: Auditorium Maximum Fresh Air Supply Requirements and NeedsAuditorium Average Fresh Air Supply Requirements and NeedsActivity Type Surface Area Average Occupancy Average Outdoor Air Requirement [m2] [people] [people/100 m2] [L/s-person] L/s- m2For the CIRS Auditorium at Average Occupancy [L/s]- People CriterionFor the CIRS Auditorium Independently of Occupancy – Area CriterionAuditorium 465 192 41 8 12 1536 5580Table 06: Auditorium Average Fresh Air Supply Requirements and NeedsAvailable SensorsThe sensors in the auditorium serve a clear purpose: help in the assessment of the thermal comfort  and air  quality  provided by  the system. Three parameters   (CO2 concentration,   relative humidity and temperature) are monitored.  As can bee seen several sensors distributed all over the  auditorium  are  used  to  measure  one  environmental  variable  (Four  for  temperature,  3  for  CO2 concentration,  3  for  relative  humidity).  This  is  way  more  than  commonly  encountered  in  most buildings. The majority of the buildings will  have at most one thermostat per zone to control  the heating or cooling ventilation. From a comparative and purely subjective perspective the selection of sensors  to  monitor  the environment offered by  the auditorium is  more than adequate.  However scientifically, how relevant is the information provided by the sensor and what are the limitation of this selection is another story.  Comments will be made with regards to this limitation is the relevant section of this report. But for the sake of argument and to support the idea currently stated a quick overview will be given as to the implications of those limitations. According to Ashrae standard 55 there are six important parameters that are involved in the assessment and definition of the thermal comfort  (metabolic  rate,  clothing  insulation,  air  temperature,  radiant  temperature,  air  speed and humidity) three of which, as can be readily noticed, are not measure by those sensors .  Page 20/74This constitute a limitation on top of the fact that the relevancy of the info is dependent on how well  the air mixes and how fast is the uniformity achieved. Discomfort can be provoked by other factors  too, such as the vertical temperature gradient that cannot be measured through these sensors. Other limitations  can  be  found  when  it  comes  to  assessing  thermal  comfort  or  air  quality  using  those sensors.List of The Auditorium SensorsSensor Brand Model Reference Additional InformationTemperature Sensor #1 Honeywell TR21 Appendix 10Temperature Sensor #2 Honeywell TR21 Appendix 10Temperature Sensor #3 Honeywell TR21 Appendix 10Temperature Sensor #4 Honeywell TR21 Appendix 10CO2 Sensor #1 Honeywell C76C32A Appendix 11CO2 Sensor #2 Honeywell C76C32A Appendix 11CO2 Sensor #3 Honeywell C76C32A Appendix 11CO2 Sensor #4 Honeywell C76C32A Appendix 11Relative Humidity #1 Honeywell H7635A1006 Appendix 5Relative Humidity #2 Honeywell H7635A1006 Appendix 5Relative Humidity #3 Honeywell H7635A1006 Appendix 5Table 07: List of Auditorium Sensors Used to Extract Data For This StudyList of The Auditorium SensorsSensor Sensor Sensor SensorWindow Opening #1 Window Opening #2 Window Opening #3 Window Opening #4Table 08: List of Auditorium Sensors Not Used to Extract Data For This Study Page 21/74Figure 02: Auditorium BMS Screen-shot - Sensors Layoutc) The Control StrategyThe control strategy was revised in the  sequence of operation for the HVAC controls manual  provided by STANTEC. The temperature of the supply air is regulated according to the temperature set  point in the auditorium. This regulation occurs through several  mechanisms. The activation of the heating coil  pump, the regulation of how much outlet air is drawn and therefore how much air is recirculated. This regulation is controlled by damper positioning. The heating coil  valve position is controlled. The amount of output air drawn is restricted by the CO2 and VOCs concentrations levels in the room. The volume of the supply air being delivered by the AHU is adjusted to maintain a duct static  pressure in the duct-work required to maintain control  on a normal  operating cooling load design day. During the project the control  strategy was revised and modified.  The revision occurred in between the two testing periods, around the end of  February.  The revision was motivated by an excess noise coming from the suction of the air into the return duct work. Some outlet vents have been plugged. The new Control Strategy/Sequence of Operations can be found in the Appendix 12; some of the main  control strategies are presented:• Warming Period: 2 hours prior to class start schedule• The mixing dampers will modulate to maintain the supply air temperature at its set point.  Page 22/74• When heating is required: Mixing Dampers=> Min OA HC and HCP ON If Fan ON and OA <13 degrees. The heating valve will be modulated to maintain the supply air temperature at set point. The heating coil pump will remain on until the outside air temperature rises to 15°C The supply fan speed will be modulated to maintain the supply air flow at its scheduled set point value.OA Flow = % SA FlowIf (RA [CO2]) – (Ambient [CO2])>750 ppm = OA Damper Max Open PositionThe SA Flow: Between 3000 l/s and 6000 l/s (Adjustable) [CO2] and [VOCs] dependent.This element of the control strategy can be observed on March 21 (Appendices 62 and 63)Data was extracted from the different relevant sensors for 5 days on automatic mode. If the trends of March 19 (Monday, Automatic Mode) are compared to those of March 5 (Monday, Override Mode, experiment 1 of trial 2) lots of similitude are noticed which supports the claim that experiment 1  is  pretty  representative  of  a  normal  day of  operation (Compare Appendix  42 to Appendix  58).  However the average system's power consumption on that day is 37 Kw while on March 5 it was 48.64  Kw (Appendices  56 and 68). March 5 was in average 1 degree Celsius colder which partially explains the difference and the real time adaptation of some of the parameters enable additional savings with respect to the reference experiment day.  On March 19 the average SA Flow is 3000  L/s and the OA Damper averages 52% opening while on March 5 it is set to be 4000 L/s for a OA Damper position fixed at 50% opening.  Page 23/74III- Data and MethodologyEvaluating  the  ventilation  system's  performance  usually  requires  measurement  of  the parameters describing its state and functioning. A considerable opportunity here, as has been seen in the previous section of this report, is the availability of numerous sensors sending data to a centralized system. The measurements obtained are compared to the design values and the standards for such building and space usage. The  system's  behavior  and  some  of  the  parameters  making  up  the  living  space  of  the auditorium  are  monitored  over  two seven  days  periods  during  which  the  system's  controls  are  overridden  and  one  5  days  period  during  which  they  are  left  on  automatic;  all  this  in  different operating and environmental conditions. The change in environmental conditions is imposed by the daily weather and tracked through the monitoring of the outside temperature and relative humidity. The narrowness of the testing period makes it as such that no significant changes are expected. The operating conditions are changed by overriding the automatic control of the ventilation system. The changes follow a certain protocol that dictates the monitoring of a reference day of operation where  certain parameters are manually fixed and than the monitoring of others days of operations; each of which  is  characterized  by  a  change  in  one  of  these  fixed  parameters.  As  will  be  seen  in  the ”Experimentation  Planning”  section of  this  report,  the  protocol  is  devised  prior  to  the  period  of interest and is distributed to the relevant CIRS staff and project mentors. To assess the air change rate when the auditorium presents a high occupation density the Equilibrium Carbon Dioxide Analysis is used, the method is described in the “Ventilation Rate and Air Change”. The feasibility and limitations of using such a technique for an auditorium is described. To consolidate the results, the analysis is  repeated several times over the two 7 days period. To further consolidate the results a Tracer Gas Decay  Method  is  relied  upon.  In  terms  of  energy  consumption  3  factors  are  considered  and explanations  given  in  the  relevant  section:  the  fans  motor  energy  consumption  deduced  by  the monitoring  of  the  amperage,  the  energy  inputted  through  the  heating  coil  deduced  by thermodynamically analyzing the air before and after the coil and finally the energy recovered in the  heat  recovery unit  common to air  handler  1 and 2.  The air  quality is  assessed by comparing the concentration level of CO2 and VOCs in the auditorium with accepted values. The limitations of such  assessment is  deduced from literature review and an proper understanding of the sensors positioning and specifications. a) Experimentation PlanningA set of experiments is devised in such a way to provide a better understanding of the effect the different parameters of the ventilation system have on the living environment provided by the auditorium and the effect on the energy consumption of the system. One experiment is conducted per day  and  the  living  environments  parameters  as  well  as  the  ventilation  system  parameters  are monitored from 9am to 4pm during the testing period. There are 4 controllable parameters of the ventilation system that can affect the living space: the ventilation rates, the room temperature set  point, the windows opening, the ratio of fresh air to recirculating air. Page 24/74The series of experimentation is to be conducted over two periods of the year one in February  one  in  March  with  the  intention  to  test  the  behavior  of  the  system  in  significantly  different ambient/atmospheric conditions dictated by seasonal changes (assuming that a month separating the two  periods  is  enough  to  observe  an  significant  change  in  ambient  conditions).  Precisely  the experiments are set for February 6 for the first set of experiments and March 5 for the second.The  system is  also  monitored  in  it's  normal  state  during  a  period  succeeding  the  second experimentation trial period for 5 days (March 19 to March 23).Experimentation Protocol Table 1Experiment 1 Experiment 2 Experiment 3 Experiment 4Experience Title Reference Windows Opened Minimal Flow Rate Medium Flow RateDescription The ventilation system is left on automatic mode – No intervention. The energy consumed and recovered is evaluated. The thermal comfort and air quality are assessed based on normal operating conditions.The ventilation System is left on automatic mode – Two of the 4 windows are left opened. The other parameters are fixed to the reference values assigned in experiment 1.The energy consumed and recovered is evaluated. The thermal comfort and air quality are assessed based on modified operating conditions.The ventilation automatic control is over-ridden. The  VFDs frequency of the fan motors are set to obtain 33% of the max flow rate capacity. The other parameters are fixed to the reference values assigned in experiment 1. The energy consumed and recovered is evaluated. The thermal comfort and air quality are assessed based on modified operating conditions.The ventilation automatic control is over-ridden. The  VFDs frequency of the fan motors are set to obtain 66% of the max flow rate capacity. The other parameters are fixed to the reference values assigned in experiment 1. The energy consumed and recovered is evaluated. The thermal comfort and air quality are assessed based on modified operating conditionsControlled or Fixed Parameter and Value AssignedFixed Windows: ClosedFixed Auditorium Temperature Set pointFixed Supp and Return Fans RPM Fixed Dampers Positions Controlled Windows: 2X OpenedFixed Auditorium Temperature Set pointFixed Supp and Return Fans RPM Fixed Dampers Positions Fixed Windows: ClosedFixed Auditorium Temperature Set pointControlled Supp and Return Fans RPM Fixed Dampers Positions Fixed Windows: ClosedFixed Auditorium Temperature Set pointControlled Supp and Return Fans RPM Fixed Dampers Positions Table 09: Experimentation Protocol Page 25/74Experimentation Protocol Table 2Experiment  5 Experiment  6 Experiment  7Experience Title Decreased  Temperature  Set PointFresh Air Intake Control Fresh Air Intake ControlDescription The Auditorium temperature set point is decreased with respect to reference by 2 degrees. The other parameters are fixed to the reference values assigned in experiment 1. The energy consumed and recovered is evaluated. The thermal comfort and air quality are assessed based on modified operating conditions.The  outside, return and exhaust damper positions are changed with respect to reference in order to decrease the amount of fresh air intake. The other parameters are fixed to the reference values assigned in experiment 1. The energy consumed and recovered is evaluated. The thermal comfort and air quality are assessed based on modified operating conditions.The  outside, return and exhaust damper positions are changed with respect to reference in order to decrease the amount of fresh air intake. The other parameters are fixed to the reference values assigned in experiment 1. The energy consumed and recovered is evaluated. The thermal comfort and air quality are assessed based on modified operating conditions.Controlled or Fixed Parameter and Value AssignedFixed Windows: ClosedControlled Auditorium Temperature Set PointFixed Supp and Return Fans RPM Fixed Dampers Positions Fixed Windows: 2X ClosedFixed Auditorium Temperature Set PointFixed Supp and Return Fans RPMControlled Dampers Positions Fixed Windows: ClosedFixed Auditorium Temperature Set PointControlled Supp and Return Fans RPM Controlled Dampers Positions (S, M, R)Table 10: Experimentation Protocol Continued Page 26/74b) Ventilation Rates and Air ChangeVentilationAs seen in the Systems Description and Control Strategy part of the report there are 3 sensors of interest that measure: the outside air flow rate, the exhaust air flow rate and the supplied air flow rate. The supplied ventilation rate can in theory be readily obtained and the ratios of flow rate per  occupant or flow rate per square meter can be compared with the standards requirements for similar buildings.  During  the first  experimentation  period,  the results  for  these  flow rates  were  deemed inconsistent and appeared to be caused by erroneously calibrated sensors. The sensors were sent back to a relevant 3rd party for recalibration. The knowledge of the flows are crucial to this study so a backup plan is elaborated and followed. The VFDs installed on the fan motors are set as they were  during the experiments. With  a  hot-wire  anemometer  the  flow rates  are  measured using  a  standardized  protocol.  Adjustments are made based on the density of air which is dependent on the relative humidity and temperature at the time of the measurement. The adjustments are made according to the following line of thoughts: Considering a derivative of the fans affinity laws:(Q1/Q2) = (D1/D2)2 (P1/P2)1/2 (ρ1/ρ2)-1/2 Q = Mass Flow RateD = Impeller DiameterP = Supply Pressureρ = DensityWhere the sub-index 1 represents the conditions at the time of the experiment and the sub-index 2 the simulated conditions. We set  P1 =  P2 by controlling the supply pressure set point.Q1 = (ρ1/ρ2)-1/2 * Q2 Where  the  densities  are  obtained  based  on  the  relative  humidity  and  temperature  of  air measured by the available sensors and the flow Q2 by manual measurement.If the supplied air temperature is below 40 degrees, the change in densities can be neglected. Page 27/74Air Change Assessment Using The CO2 Concentration Equilibrium Point MethodologyThe equilibrium technique for the assessment of the air change rate can be used when the outside CO2 concentration and the CO2 generation within the system analyzed is constant. In this case an equilibrium concentration will be reached at a certain point in time within the system. During a  class,  even if  the CO2 generation rate is constant, due to the maintained occupancy  level  of the auditorium, equilibrium might not be reached due to insufficient time. The only way to determine this  is to observe the data extracted from the CO2 sensors and determine if at some point in time during a class the CO2 concentration level stabilizes itself. If the outdoor CO2 concentration Cout is constant and the average CO2 generation rate per person out Gp is known, then the outdoor airflow rate Q into the building is given by the following equation:Q= Number of occupants∗GpCeq−CoutThe value of Gp depends on a person’s age and activity level. A typical value of Gp for office buildings is 5.3 x 10-6 m3 /s (0.011 cfm) per person. The value of Q is divided by the building volume V to  determine the air change rate.Air Change Assessment Using a Tracer Gas Methodology The technique consist in turning off the ventilation system and than releasing a certain amount of pressurized tracer-gas from a cylinder. This amount is determined in a way that, when released in the auditorium, it results in  a detectable change of the  tracer-gas concentration that lasts despite the system's leaks prior to the start of the experiment. The gas is allowed to mix with the internal air while the fan in the air-handling unit is switched off.  The fan is then switched on and the decay of the concentration of the tracer gas is monitored over a given time interval:C(t) = C(0)e−It The logarithm of the tracer-gas concentration is plotted against the elapsed time and the slope of the line is equal to l. This technique can be accurate when it is used in buildings and rooms because  the change rate is low and by using a portable fan a good mixing of  the gas and the air can be  achieved.The Volume of the auditorium in liters is determined by looking at the relevant drawings.There are no limitations as of the choice of the tracer-gas that can be chosen as long as it can be detected by the tools in the experimenter's possession and as long as it is in conformity with the  safety standards set for this technique which are pretty obvious and will not be stated (orderless gas,  non flammable, non toxic etc...) Page 28/74There are usually two possible protocols/methodologies that can be followed when proceeding with this technique: The first one consist in turning the system into a living laboratory equipped with sensors by having the analysis  equipment on site (which is,  in some way,  what the auditorium is with all  the sensors it presents; provided an adequate choice of tracer gas). This first method can be very cumbersome and costly. The other way would be to extract (by pumping into sealed sample bags) an air mixture sample at different point in time and send it to an external lab for analysis of the changing of the tracer-gas  concentration within the mixture. The test is usually performed in a closed system, emptied from all occupants. It was chosen that the  experiment should take advantage of the existing ability to accurately measure CO2 on site; as a result CO2 was chosen as a tracer gas.  One would need to significantly increase the auditorium's CO2 level above the ambient concentration for the measurements to be relevant and for the measurements not to beaffected by the “noise” created by the environment. It was planned that CO2 cylinders would be bought and the gas released in the auditorium at the time of the testing to significantly increase the CO2 concentration levels. The initial concentration of CO2 in the auditorium environment is equal to :C i= miV auditorium Which is around 400ppmA pressurized CO2 cylinder of Volume Vcylinder in liters containing a mass mcylinder milligrams of CO2 is obtained.The new CO2 concentration level to be expected and detected after the release is:Cn=mi+mcylinderV auditorium PFAn arbitrary value is chosen such as Cn>2xCi the amount of cylinders or size of the cylinder needed can be readily derived from these results.As  it  will  be  shown in  the  results  section  of  this  report  associated  with  this  topic  the  plan  was  modified. Page 29/74c) Energy ConsumptionIn  this  part  of  the study,  the energy consumption of  the fans,   the  energy  input  into  the supplied air and the energy recovered are of interest. The methodology followed to obtained each of  these parameters is described. The FansThe power drawn by the motor of each fan is either directly measured (trial 2) or can be calculated (trial 1) since the current is independently measured:P=SQRT(3)*V*I*PFWhere the value of the current I  is obtained from the sensors available on site and logged in the system. The voltage is readily obtained and the power factor assumed.Heating of the AirWhen needed heat is added to the air mixture (outlet air and return air) prior to being supplied to the auditorium. The energy added by the coils is nothing but the difference in enthalpy of the air mixture and the supply air. The enthalpy of air is dependent on both the relative humidity and the temperature  of  the  air  which  are  both  measured  in  the  system.  Many  literature  elaborate  the derivation of the following formulas, for simplicity the engineering toolbox site was consulted and some part are directly quoted from the site. Figure 03: Thermodynamic CV 1st Law Analysis on Supply Air  Page 30/74The 1st Law of Thermodynamic is applied on a control volume within the air supply duct that  encompasses the air passing through the coil only. This is what figure 03 attempts to illustrate.The simplified equation, assuming steady state and neglecting, kinetic and potential energy is:Q˙i=m˙(ho−h i) Where m˙=ρQ• The supply flow Q is measured by a sensor. • The density requires the knowledge of the relative humidity of the moist air at any point in  time, parameter which is measured by a sensor. • As  for  the  enthalpy,  two  parameters  are  to  be  known,  the  relative  humidity  and  the temperature of the moist air; these parameters are measured by sensors.Two equations, taken from the engineering toolbox site are used the density of the air stream can be  deduced as well as its enthalpy prior and after the potential heating: [1] h = (1.006 kJ/kgoC) t + x [(1.84 kJ/kgoC) t + (2501 kJ/kg)][2] ρ = ρda (1 + x) / (1 + 1.609 x ) A sample calculation will be shown in the results section.Heat RecoveryFigure 04: Thermodynamic Model of The Heat Recovery UnitNote: In this figure m=mass flow rate, T=Temperature, R=Relative Humidity Page 31/74The outlet ducts of both AHU1 and AHU2 channel the air exhausted from the auditorium and the rest of the building though a heat recovery unit prior to releasing it to the atmosphere. The total  energy recovered is provided by a sensor installed at the level of the heat recovery system. However the energy recovered from the outlet air of the auditorium is of greater interest in the context of this study.  Most  of  the  concepts  elaborated  in  the  previous  section  still  apply  here.  To  answer  the question of how much energy is extracted from the AHU2 however an adequate modeling and choice of the control volume is needed when applying the 1st law of thermodynamic. It is imagined that the flows  never  mixes  before  entering  the  heat  recovery  unit.  The  stream of  air  from AHU2  is  also  assumed to leave at the same temperature as that of the mixed outlet air in the actual systemQ˙r=m˙(h3−h2)d) Air Quality Assessment Volatile Organic Compounds Concentration [VOCs]:With regards to air quality, the VOCs concentration is monitored in the auditorium, the results  interpreted and compared to accepted standards for such metric and conditions. The limitations of  relying the existing VOC sensors is identified and attention is drawn to what should be further taken  into account when it comes to air quality.VOCs are organic  compounds characterized by their  tendency to evaporate easily  at  room temperature. They are quite detectable, but usually only by means of broad-range sensors. Broad-range  sensors  provide  an  overall  reading  for  a  general  class  or  group  of  chemically  related  contaminants.  They cannot distinguish between the different contaminants they are able to detect.  They provide a single aggregate reading [TVOC] for all of the detectable substances present at any  moment. The limitation of this is that different VOCs have different permissible exposure limits and a  lack of an unacceptable aggregate reading is not necessarily proof of the absence of hazard. In  order  to  understand  the  implications  of  the  VOCs  concentration  measurements,  their significance and their limitations in assessing air  quality,  information is mainly extracted from the related sensor user’s manual and presented in this section; other sources are consulted to support the results interpretation.The  Air  Quality  Monitor  being  dealt  with  is  a  broad-range  sensor,  it  uses  a  tin  dioxide semiconductor based on the Taguchi principle to detect oxidizable gases and is specifically designed to have high sensitivity to gaseous organic materials which are components of indoor air pollutants. The sensor is essentially a heated element inside a porous semi-conductive tube. The tube has a large surface area and is able to freely absorb gas molecules such that electron transfer occurs between the gas and oxygen molecules. This causes relatively large increase in conductivity for a small change in  gas concentration. The change occurs within a few seconds and is completely reversible.  Page 32/74The sensor responds with a varying degrees of sensitivity to a wide variety of gases which include  hydrogen,  hydrocarbons,  alcohols,  carbon  monoxide,  benzene,  etc...  Some  of  the  detectable pollutants are presented in decreasing order of detection sensitivity in the following table. Hydrocarbons  and body odors which constitute a significant chunk of the VOCs present in a human  environment  are  emitted  by  breathing  and perspiration.  The  level  of  these  contaminants change at roughly the same rate as CO2  and the sensor will track these contaminants at the same rate as the CO2  in occupied spaces. Er words it is expected that over a given test period the trends of VOCs and CO2 concentrations behave the same (to some extend CO2  concentration could be predicted from the VOCs concentration). Figure 05b illustrate what can be expected in terms of CO2 and VOCs concentrations in an occupied space such as the auditorium and the correlation between them.Figure 05a: Detectable VOCs Page 33/74Figure 05b: Correlation of CO2 and VOCs Concentrations as Measured in a Typical conference RoomCarbon Dioxide Concentration [CO2]:The carbon dioxide, at levels such as usually encountered in living spaces, does not represent a health hazard but can be a major source of discomfort and dizziness for occupants if present in a considerable level within an occupied space, such as the auditorium being studied. The acceptable range for both VOCs and CO2 concentrations vary according to the type of activity occurring withing the living space. Most (older) ventilation systems are not equipped with VOCs and CO2 sensors and guarantee that the living environment has an adequate range  of VOCs and CO2 concentration through sufficient  air  renewal  rates  (i.e  fresh air  intake)  which are  set  by  the  standards, based on room occupation and activity type (this has been covered in previous sections of this report). The advantage of having those sensors available is that energy savings can be obtained through some modifications (such as a fan speed decrease) at the expense of air quality until critical levels are reached  and  the  energy  saving  changes  can  be  attenuated/reverted  in  order  for  the  monitored parameters to remain in tolerable ranges. The procedure is quite straight forward, verify that at all time, whatever the control changes implemented, the CO2 concentration in the auditorium stays within the limits: under 1000ppm. Page 34/74e)Thermal Comfort  Assessment ASHRAE  has  developed  a  standard  (known  as  ASHRAE  Standard  55-2004  Thermal Environmental Conditions for Human Occupancy ) to describe comfort requirements in buildings. This standard specifies the combinations of indoor thermal environmental factors and personal factors that will  produce  thermodynamic  environmental  conditions  acceptable  to  most  occupants  within  the space. A  comfort psychometric chart is derived from this set of guidelines and can applied to spaces where the occupants have activity levels associated to metabolic rates between 1.0 met and 1.3 met and where clothing is worn that provides between 0.5 clo and 1.0 clo of thermal  insulation.  The comfort zone is based on the PMV values between -0.5 and +0.5. Figure 06: ASHRAE Standard 55-2004 Comfort Psychometric ChartA survey was to be conducted at the end of each class given in the auditorium where each student would have chosen a score among a predefined set of scores to evaluate his perception of the thermal  comfort.  However  due  to  some  difficulties  encountered  and  advice  provided  by  the supervisor the survey aspect of the study was dropped.For each class the average temperature as well as the average relative humidity is placed on the graph to assess weather thermal comfort is achieved according to this definition and for the given experiments, the results are posted in a table. Page 35/74IV- Data Interpretation and Analysis – ResultsNote: Appendices 26 to 68 are crucial to the understanding of this part of the report!a) Experimentation Outcome: Actual Occurrence and Obstacles EncounteredThe  experiments  were  intended  to  be  performed  as  planned  but  a  series  of  obstacles,  encountered  during  the  1st testing  period,  delayed  their  execution  and  others  affected  the rigorousness of the methodology or lead to a partially inconsistent/unreliable data collection. This defeated  the intention  of  having  two comparable  sets  of  experiments,  however  it  presented the opportunity to be used as a learning element to refine the methodology and avoid mistakes in the next trial. Obtaining inconsistent results usually motivates a repetition of the trial (as in replacing the 1st set of experiments) but this was not done for several reasons:• 1st of all the experimentation process requires a considerable involvement and attention from behalf of the building operator who cannot be asked full dedication to this project. • 2nd of all the inconsistent results are valuable in a sense that they pinpoint weaknesses in the system and potential defects and are also representative of the kind of obstacles that can be encountered in any potential future analysis of the system. • Finally keeping the situation as such is very consistent with engineering work where projects executions seldom occur without obstacles. During the month of February, the system was still being commissioned, tested and altered by third parties; its whole control strategy was revised, making the comparison between the two sets of experimentation unfeasible. As can be noticed from the following table no obstacle were encountered during the second round of experiments. In this trial, resembling experiments were placed during days of similar class  schedule to reduce the occupancy effect and focus on the changes implemented outcome. It was noticed in the 1st run that heat recovery was sometimes bypassed by automatic control so this  was avoided by overriding the damper  positions  for  exhaust  air  streams to be channeled through the heat recovery units.No incidents were recorded during the 5 days of automatic operation monitoring however odd results  were noted on March 22 and 23 (Appendices  64 to 67)  such as  an unusually  low energy consumption on March 23 as if there was no heating at all of the air and an unjustified interruption of  the heating from 11am to 1pm on March 22 (despite the fact that the OA was 5 degrees). Page 36/74Table 11: Experimentation Placement, Protocol and Obstacles Encountered Page 37/74Experiments Schedule and Protocol FollowedWednesday Feb 8 Thursday Feb 9 Friday Feb 10Windows: Closed Windows: 2 open Windows: ClosedRoom Temp: 21C Room Temp: 21C Room Temp: 19CSupply fan: 60Hz Supply fan: 60Hz Supply fan: 60HzReturn fan: 54Hz Return fan: 54Hz Return fan: 54HzSupply air damper: 50% Supply air damper: 50% Supply air damper: 50%Obstacles EncounteredMonday Feb 13 Tuesday Feb 14 Wednesday Feb 15 Thursday Feb 16Windows: Closed Windows: Closed Windows: Closed Windows: ClosedRoom Temp: 21C Room Temp: 21C Room Temp: 21C Room Temp: 21CSupply fan: 20Hz Supply fan: 40Hz Supply fan: 60Hz Supply fan: 60HzReturn fan: 18Hz Return fan: 36Hz Return fan: 54Hz Return fan: 54HzSupply air damper: 50% Supply air damper: 50% Supply air damper: 30% Supply air damper: 70%Experiments and Schedule Monday March 5 Tuesday March 6 Wednesday March 7 Thursday March 8 Friday March 9Windows: Closed Windows: Closed Windows: Closed Windows: Closed Windows: ClosedRoom Temp: 21C Room Temp: 21C Room Temp: 21C Room Temp: 21C Room Temp: 21CSupply fan: 60Hz Supply fan: 24Hz Supply fan:60Hz Supply fan: 42Hz Supply fan: 60HzReturn fan: 54Hz Return fan: 21.6Hz Return fan: 54Hz Return fan: 37.8Hz Return fan: 54HzSupply air damper: 50% Supply air damper: 50% Supply air damper: 30% Supply air damper: 50% Supply air damper: 70%HRC - full coil HRC - full  coil HRC - full coil HRC - full coil HRC - full coilMatch with March 12 Match with March 9 Match with March 7Monday March 12 Tuesday March 13 Wednesday March 14 Thursday March 15 Friday March 16Windows: Open Windows: ClosedRoom Temp: 21C Room Temp: 19CSupply fan:60Hz Supply fan: 60HzReturn fan: 54Hz Return fan: 54HzSupply air damper: 20% Supply air damper: 50%HRC - full coil HRC - full  coilExperiments and ScheduleSystem override remotely overriden by contractors. Dampers Position drifted away from 50% from 10:50 to 11:15 and system went back on automatic from 2:20 to 2:30Faulty window opening indicatorSystem override overriden by contractors. Return fans were set to 70Hz instead of 54Hz for a brief period of time from 8:19 to 8:24Experiments and ScheduleObstacles Encountered Override interrupted because crtitcal of level of CO2 were reached in the auditoriumSystem crash, data collection interruptedHeating valve forced at 100% opening by contractors from 10am to 3pmHeating valve forced at 100% opening by contractors from 8:55am to the end of the dayMatch with March 8, 13Match with March 6, 13Experiments and Scheduleb) Ventilation Rates Assessment ResultsVentilationIn the middle of the semester it was noted that two (EA, OA) out of the three flow sensors of  the Air Handling Unit of the auditorium were uncalibrated. Unfortunately in this case, the knowledge of  the  flows are  crucial  in  a  ventilation  system assessment  study.  A  “plan  B”  was needed which consisted of manual measurements. This “plan B” presented numerous limitations that are going to be commented. The ventilation flows are a result of several factors such as the fan speeds, the dampers  positions, the ambient conditions (relative humidity of air and thus density). If the system is left on automatic  the  dampers  positions  will  keep  on  changing  and  one  has  no  control  over  ambient conditions which makes it impossible to recreate a situation for every condition where the measured flow would be representative of what was actually happening at a certain point in time of interest.  During the experimentation process, the automatic control was overridden; while many parameters differ from one experiment to another  they all present a common set of parameters: mainly the fan speeds  and  damper  positions.  It  was  decided  that  the  measurement  would  be  taken  at  normal operating conditions fan speeds and the two fan speeds that were tested during two experiments along an average damper position of  50%. It  was deemed, that  if  accurate,  the results  would be representative enough of the overall system's behavior but wouldn't allow elaborate derivations of energy involvement which require accurate measurements. The measurement were performed by a trained technician due to the restricted access of the ventilation system's room to students. As can be noted from the table to follow, two techniques were relied upon which are air velocity and pressure measurements; flows were subsequently derived and compared to the flow-meter readings. Due to the  difficulty  in  accessing  the  system,  the  air  velocity  measurement  couldn’t  follow standardized protocols described in the reviewed sources and thus resulted in inaccurate and unreliable results. The results derived from pressure measurements were deemed more reliable. It is worthy to note that  outside air intake flow can be derived from CO2 concentration monitoring techniques such as will be covered in the next sections of this report. The results obtained will be compared to the outside air  requirement criterion previously cover for both average and maximum occupancy. Please refer to the auditorium space occupancy usage section for further details. Page 38/74Table 12: OA, EA, SA Manual Measurements ResultsOutside Air Flow Assessment Using Two Different Techniques – Comparative TableOA Flow @ 50% Damper Position and avg. fans speedsOA Flow @ 50% Damper Position and medium fans speeds (2/3 avg) OA Flow @ 50% Damper Position and minimum fans speeds (1/3 avg) Occupancy based Outside Air Requirement CriterionArea based Outside Air Requirement CriterionAverage Occupancy5522 or NA NA or NA NA or 2296 1536 5580Maximum Occupancy5522 or NA NA or NA NA or 2296 3408 5580Table 13: Outside Air Flow Intake Assessment Using Two Different TechniquesNote: In each cell the left result is based on manual measurements and the right one on [CO2] equilibrium. The color coding is green for two criterion met  per evaluation, yellow for one and red for none. Page 39/74Air Flow Measurements ResultsUsing Measured Pressure Using Measured VelocityPressure FlowLocation Time Meas. Calc Calc Calc Meas. Calc Calc Meas.Pa liter/sec m3/sec liter/sec liter/secTest 1 HRC 10:59 0.00 0.00 0.00 0 0.2 0.204 204AH2 SA 11:08 0.08 19.92 5.70 6181 1.1 1.192 1192 4281AH2 OA 11:12 0.03 7.47 3.49 5522 0.5 0.791 791 2665AH2 EA 11:14 0.01 2.49 2.02 3024 0.12 0.180 180 3321Test 2 HRC 13:15 0.02 4.98 2.85 2914 0.3 0.307 307 2368AH2 SA 13:20 0.04 9.96 4.03 4371 1.32 1.431 1431 200AH2 OA 13:24 0.00 0.00 0.00 0 0.15 0.237 237 3784AH2 EA 13:27 0.00 0.00 0.00 0 0.09 0.135 135Test 3 HRC 14:29 0.00 0.00 0.00 0 0.13 0.133 133AH2 SA 14:32 0.01 2.49 2.02 2185 0.22 0.238 238 493AH2 OA 14:41 0.00 0.00 0.00 0 0 0 0 -61AH2 EA 14:43 0.00 0.00 0.00 0 0 0 0 2447Test conditions Duct Dimensions Duct area Air DensityMeas. Meas. Calc 1.225  kg/cubic meterSF (Hz) RF (Hz) Dampers Width (") Height (")Test 1 59.5 53.9 50% 44 36 1584Test 2 41.7 32.7 50% 60 28 1680Test 3 23.8 21.7 50% 57 43 245193 25 2325* Flow Stationinch wcVelocity (m/sec)Velocity (m\s)Area (sq inch)The  accuracy  of  the  results  obtained  is  questionable  but  are  revealing  of  the  scale  of  magnitudes being dealt with and a rough estimate of the ventilation adequacy can be made. The occupancy based criterion is  the most  relevant  one and it  is  highly  met,  except  at  minimal  flow.  However the inadequacy at minimal flow was also confirmed in later testings where it was noticed that  it  results  in  unacceptable  CO2  levels  concentration  being  reached.  In  any  case  the  system automatic control can increase the outside air intake to up to 100% (No recirculating air) if critical CO2 levels are reached.Air Change Assessment Using The CO2 Concentration Equilibrium Point MethodologyReviewing some sources dealing with this matter, it is expected that if equilibrium is not truly reached,  the  technique  would  lead  to  unreliable  and  overestimated  results.  The  problem in  the situation being dealt  with is  that  the auditorium occupancy is  permanently  fluctuating over  brief periods of time making any equilibrium hard to be reached. However  attempts  were  made  to  apply  the  technique  while  considering  time  laps  where equilibrium  is  arguably  reached.  Some  results  seemed  satisfactory  and  in  accordance  with  the presumably uncalibrated sensors others were deemed irrelevant and inaccurate such as highlighted in the table. The common ground between those two inaccurate results is that they are derived through the  assessment  of  very  small  changes  of  concentration  levels  of  the  auditorium  from  ambient conditions. It is suggested that for auditoriums, air change rate should range between 8 and 15 ach. It is  not feasible that the outside air  is  higher than the supply air,  which is  basically  the case in all  experiments. The  inaccuracy  is  mainly  due  to  the occupancy  that  was  not  evaluated  in  real  time ,  the expected  amount  of  CO2  generated  per  person  and  finally  the  shortness  of  the  periods  where equilibrium is reached.Table 14: CO2 Concentration Equilibrium Methodology for OA Flow Assessment Results Page 40/74[CO2] Equilibrium Methodology ResultsExp.1 1 No Equilibrium2 1 10:15 to 11:00 227 420 720 4010 3680 5663 3240 4.46 4.093 1 11:00 to 11:30 202 470 786 3388 3418 3240 3.76 3.804 1 11:00 to 11:30 202 411 1201 1355 3369 3607 3240 1.51 3.745 1 No Equilibrium6 1 11:00 to 11:30 202 513 835 3325 3342 5663 3240 3.69 3.717 1 10:00 to 10:30 255 441 529 15358 4669 5663 3240 17.06 5.191 2 10:30 to 11:30 202 412 578 6449 3976 3240 7.17 0.002 2 12:00 to 13:30 227 427 951 2296 975 3240 2.55 0.003 2 10:30 to 11:30 202 486 732 4352 4096 3240 4.84 0.004 2 No Equilibrium 3691 3240 0.005 2 14:00 to 16:00 103 471 486 36393 3802 3240 40.44 0.006 2 10:30 to 11:00 257 406 710 4481 39917 2 10:00 to 11:30 255 406 716 4360 2921 3240 4.84 0.00Test PeriodTime at which [CO2] Equilibrium achievedNumber of Occupants when Eq. ReachedAmbient [CO2] – C(out)Equilibrium [CO2] – C(eq)Q[L/s] – Outside Air – CalculatedOutside Air – MeasuredSupply AirAuditorium VolumeAir Change Rate – Based On CO2 EqAir Change Rate – Based On MeasurementAir Change Assessment Using a Tracer Gas Decay Methodology When time  came  to  proceed  with  the  air  change  assessment  using  the  tracer  gas  decay technique, as originally planned, a specialized company (PIXAIR) was consulted for the purchase of the CO2. It appeared that to raise the CO2 concentration level of the auditorium to the required level of  800ppm (about 400ppm above the ambient CO2 concentration; this is equivalent to 1295 Kg of CO2 to be  release  given  the  size  of  the  auditorium)  a  significant  and  costly  amount  of  CO2  was  to  be purchased. It is worthy to note that if another gas had been chosen such as SF6, because of the absence of it in ambient air only a small amount of it would be needed thus reducing the cost of the procedure.  However other costs would have been incurred mainly related to the purchase of the air  sample  extraction equipment (manual pumps and sample bags) and the lab analysis. CO2 purchase for the Tracer Gas Decay Methodology: Costs Mass Volume Concentration Price at [30$/20lb]LB [Kg] mg L PPM or mg/L $22 10 1.00E+07 3.24E+06 3 $3333 15 1.50E+07 3.24E+06 5 $5044 20 2.00E+07 3.24E+06 6 $6655 25 2.50E+07 3.24E+06 8 $83110 50 5.00E+07 3.24E+06 15 $165165 75 7.50E+07 3.24E+06 23 $248220 100 1.00E+08 3.24E+06 31 $330275 125 1.25E+08 3.24E+06 39 $412.002849 1295.2 1.30E+09 3.24E+06 400 $4,274.00Table 15: CO2 purchase for the Tracer Gas Decay Methodology Costs It was finally decided that instead of purchasing CO2 and releasing it, the experiment should be conducted after a class where the auditorium would have been occupied for a certain period of time. This  would  provide  the  needed CO2 for  free.  After  a  quick  glance  at  the  auditorium occupation schedule, classroom services was contacted, the auditorium was reserved for Thursday the 22nd of March from 12:30pm to 2pm. During this day, fan speeds and fresh air intake were reduced to minimal but acceptable values to allow the accumulation of CO2 within the auditorium. At the end of the class,  the vacant auditorium was locked and all  windows closed, the ventilation system was shut down.  About half an hour passed, allowing the concentration of CO2 in the auditorium referred as initial, to stabilize  itself.  The  system  was  turned  on  using  the  same  parameters  used  in  the  reference experiment. The CO2 decay was monitored and the air change rate derived from it as will follow. Page 41/74Figure 07: CO2 Concentration Decay Experiment Explained Page 42/74Figure 08: Overview of CO2 Concentration Decay Over Experimentation Period Page 43/7412:0012:0412:0812:1212:1612:2012:2412:2812:3212:3612:4012:4412:4812:5212:5613:0013:0413:0813:1213:1613:2013:2413:2813:3213:3613:4013:4413:4813:5213:5614:0014:0414:085.405.605.806.006.206.406.606.807.007.207.40 [CO2] Decay Experimentation PeriodCO2_NECO2_NWCO2_SECO2_SWAvg. Auditorium [CO2]CIRS_OUTSIDE_AIR_CO2RETURN_AIR_CO2Natural Logartihm of [CO2]Figure 09: Forced CO2 Concentration Decay Monitoring Over 10min and 30min PeriodFigure 10: Natural CO2 Concentration Decay Monitoring Over a 45min Period Page 44/740 200 400 600 800 1000 1200 1400 1600 1800 20006.006.106.206.306.406.506.606.706.806.90f(x) = -0.00024x + 6.72340R² = 0.96254Forced CO2 Concentration Decay 30mins Monitoring: LN[CO2] vs. Time ElapsedLN [CO2]Linear Regression for LN [CO2]0 500 1000 1500 2000 25006.746.766.786.806.826.846.866.886.906.92f(x) = -0.00004x + 6.89303R² = 0.99056Natural CO2 Concentration Decay 35mins Monitoring: LN[CO2] vs. Time ElapsedLN [CO2]Linear Regression for LN [CO2]0 100 200 300 400 500 600 7006.306.326.346.366.386.406.426.446.466.486.50f(x) = -0.00018x + 6.47776R² = 0.99653Forced CO2 Concentration Decay 10 mins Monitoring: LN[CO2] vs. Time ElapsedLN [CO2]Linear Regression for LN [CO2]Air Change Rate Assessment Results through CO2 Concentration Decay Monitoring MethodologyAssisted Air Change @ Vent. Sys. settings: SF 60Hz RF 54Hz and 50% DP Natural Air Change/Leaking EnveloppeOver 10 min Period (13:30 to 13:40) Over 30min Period (13:15 to 13:45) Over 45min Period (13:15 to 13:45)Air Change (1/s) Air Change (1/h) Air Change (1/s) Air Change (1/h) Air Change (1/s) Air Change (1/h)1.80E-004 6.48E-001 2.40E-004 0.86 4.00E-005 0.14>93% Uncertainty >93% Uncertainty Unknown580L/s Corresponding OA Flow 770L/s Corresponding OA Flow 130L/s Corresponding Leak Flow14% of Air Supplied 18.3% of Air Supplied NATable 16: ACR Assessment Results through [CO2] Decay Monitoring MethodologyFigure 07 is self-explanatory, however what is interesting to note is the stratification of the air  within the auditorium as clearly revealed by the CO2 curves that deviate from one another when the  ventilation system is turned off and that merge when it is turned back on. During the CO2 accumulation phase the CO2 concentration is always higher in the South West part  of  the  auditorium.  The  fact  that  higher  CO2  level  are  observed  in  the  West  can  be  clearly explained by the preference of students to sit closer to the front of the class. Why the South side is concerned can hardly be explained but one can assume a higher density of students on this side. Another observation that can be made is the CO2 levels that are actually lower at the front of the class (NW and SW) than at the back when the ventilation system is turned off, despite the fact that most of the CO2 was generated by the student in the West. Here is a possible explanation: air is forced into the auditorium by the ventilation system from East to West and returned to the system at the  west (the front of the class). When the system is turned on, the CO2 generated by the students (in  majority sitting at the front of the class) has a tendency to diffuse from high concentration areas to  low ones (despite a higher density than air and the elevation) but when it does so, it encounters resistance from the forced air  flow coming in  the opposite  direction  and preventing its  diffusion (sensors in the East will have a greater tendency to measure CO2 levels from the fresh air). As a result there is a stagnation of the CO2 at the front of the class and an accumulation until it is reabsorbed by  the system. The auditorium is part of a larger system which is the CIRS building and which is ventilated by  its own independent system (AHU1). Ventilation systems are designed in such a way to maintain a  positive pressure within the ventilated system, to avoid non-preheated infiltrations of the air from the outside  which  is  usually  cold.  When  the  auditorium ventilation  system (AHU2)  is  turned off  the pressure within the building becomes higher than within the auditorium. Air has a tendency to leak in  from  the  inner  building  to  the  auditorium  and  than  out  again  (both  building  air  pressure  and auditorium air pressure remain higher than the atmospheric pressure). The doors of the auditorium are located West and this is where the major leakage from the building to the auditorium occurs. This leaking air  from the building will  therefore  push the existing auditorium air  East.  The behavior  is  illustrated in the following figure. Page 45/74Figure 11: Stratification of the Air in the Auditorium Explanation The  natural  decay  due  to  leaking  is  quite  considerable  this  is  due  to  the  fact  that  the auditorium despite being isolated is no completely air  tight and as has previously been discussed receives leaking air from the building interior itself. The building is mechanically ventilated by AHU1 so even when AHU2 is shut off it partially benefits from a mechanically supported air renewal. In other words the decay is more important that if only leaking to the outside was relied upon. The ventilation system plays an important role in mixing the air and thus achieving uniform conditions within the auditorium. The trends plotted for the concentration decay are satisfactory and show an expected behavior which is well represented by the associated linear regressions.There is a large difference in the results obtained from both methods at the time being it is  therefore hard to conclude despite that the CO2 decay method would be deemed more adequate in  this  situation.  Despite  the  discrepancy  in  the  results  from  both  methodologies,  everything  is  presented as calculated and analyzed. c) Energy ConsumptionA major  difficulty  was encounter  while  dealing with this  part  of  the project.  The program written to analyze the data was designed in a way to refrain from calculating the energy input to the supply air when the system is turned off. Results were obtained but didn't make sense at all. After  thorough revision it was noted that the heating valve position sensor readings of AHU2 coil could not be relied upon to determine weather heating is occurring or not. Most of the time the heating was enabled but the valve appeared to be closed giving a false indication that no heating was occurring.  The data had to be reprocessed again for the 14 experiments on a very short notice.  Page 46/74The energy related results for the second experimentation series are presented in this section and the related graphs and trends can be found in the appendix section. A analysis integrating the numerical tables and graph is performed to deduce the important points.Figure 12: Typical AHU2's Energy Consumption Behavior – Reference Experiment March 5 Page 47/740:00 1:30 3:00 4:30 6:00 7:30 9:00 10:30 12:00 13:30 15:00 16:30 18:00 19:30 21:00 22:300.0010.0020.0030.0040.0050.0060.0070.0080.0090.000.005.0010.0015.0020.0025.00Ventilation System Energy Chart - MAR 5AHU2 - SA Heating RateAHU2 -SF Power Consumption AHU2 -RF Power Consumption AHU2 -Heating Pumps Power Consumption AHU2 -Total Energy Consumption RateAmbient -TemperatureAuditorium -TemperatureTemperrature [Deg C]Table 17: Numerical Energy Absolute Value Analysis for Test Period 2 Page 48/74Numerical Energy Absolute Value Analysis for Test Period 2Parameter T2:Exp1 T2:Exp2 T2:Exp3 T2:Exp4 T2:Exp5 T2:Exp6 T2:Exp7Average Auditorium Temperature Average 20.5 20.5 20.6 20.8 20.6 20.8 19.2Min 20.1 20.5 20.5 20.3 20.3 20.6 19.2Max 20.6 20.5 20.9 21.3 20.7 20.9 19.2Average 16.7 17.2 15.1 14.0 13.9 15.6 14.5Min 15.5 15.7 13.0 11.4 13.7 14.5 13.1Max 17.5 18.3 17.3 16.0 14.3 16.6 16.5Average 0.06 0.00 0.05 0.07 0.05 -0.03 0.00Min -0.30 0.00 -0.05 -1.50 -0.11 -0.35 0.00Max 1.51 0.00 1.20 1.51 1.17 0.04 0.00Heating Rate of AHU2 SA (Kw) Average 35.59 3.25 4.16 8.19 43.91 6.46 13.65Min 25.20 0.00 0.00 0.00 38.92 0.00 6.97Max 47.83 10.73 9.57 17.75 47.87 13.63 26.62SF Power Consumption of AHU2 (Kw) Average 7.01 0.50 6.94 2.14 6.79 6.44 6.64Min 6.70 0.50 6.90 2.10 6.71 6.10 6.60Max 7.10 0.50 7.00 2.50 6.80 6.60 6.80RF Power Consumption of AHU2 (Kw) Average 2.78 0.30 3.67 1.66 3.32 3.17 2.77Min 2.60 0.30 3.50 1.30 3.30 2.90 2.60Max 3.40 0.30 3.90 1.70 3.56 3.30 3.40Heating Pumps  Pow. Con. (Kw) Average 1.08 1.13 1.07 1.12 1.11 1.10 1.11Min 1.08 1.12 1.04 1.12 1.09 1.09 1.11Max 1.09 1.15 1.13 1.12 1.12 1.12 1.11Total Energy Consumption Rate (Kw) Average 48.64 9.48 17.41 17.86 57.14 19.42 26.79Min 38.25 6.24 13.19 9.66 51.98 12.96 20.12Max 60.88 16.93 22.88 27.41 61.12 26.57 39.76Delta T: Auditorium - AmbiantAud. Temp Change Rate (deg C/h)Table 18: Numerical Energy Deviation Percentage From Average Analysis for Test Period 2Comments will be made with respect to experiments individually and in relation with other experiments. Lessons learned from on experiment and mentioned will not be repeated for the other experiments.  The  following  paragraph  can  accustom  the  reader  to  integrate  the  graphical  and numerical results and draw his own conclusions. The  paragraph can serve as commenting and analysis protocol. On the 5th of March when the reference day experiment was performed, a peak heating load can be observed at 6:30 Am (graph for the whole day: Ventilation System Energy Chart March 5); this is when the ventilation system is turned on. The peak is explained by a reaction of the control system to the detection of a low temperature in the auditorium which cools down from 20.5 to 20.1 over  night (Table 17 and Appendix  43). Over night, the ventilation system is shut off, however, despite the fact that the dampers are closed to keep the hot air in, heat leaks through the building envelope and  along some air  leaks.   The  peak  load  represents  about  20% of  the  average  heating  load  for  the occupation period. The slope of the heating curve is the highest at this point.  Page 49/74Numerical Energy Deviation Percentage From Average Analysis for Test Period 2Parameter T2:Exp1 T2:Exp2 T2:Exp3 T2:Exp4 T2:Exp5 T2:Exp6 T2:Exp7 AvgAverage Auditorium Temperature Average 0% 0% 1% 2% 1% 2% -6% 20.4Min -1% 1% 1% 0% 0% 2% -5% 20.2Max 0% 0% 2% 4% 1% 1% -7% 20.6Average 9% 13% -1% -8% -9% 2% -5% 15.3Min 12% 13% -6% -17% -1% 4% -6% 13.9Max 5% 10% 4% -4% -14% 0% -1% 16.6Average 99% -100% 88% 149% 81% -216% -100% 0.0Min -9% -100% -84% 353% -66% 6% -100% -0.3Max 94% -100% 55% 94% 51% -94% -100% 0.8Heating Rate of AHU2 SA (Kw) Average 116% -80% -75% -50% 167% -61% -17% 16.5Min 148% -100% -100% -100% 283% -100% -31% 10.2Max 92% -57% -61% -29% 93% -45% 7% 24.9SF Power Consumption of AHU2 (Kw) Average 35% -90% 33% -59% 30% 24% 27% 5.2Min 32% -90% 36% -59% 32% 20% 30% 5.1Max 33% -91% 31% -53% 28% 24% 28% 5.3RF Power Consumption of AHU2 (Kw) Average 10% -88% 45% -34% 32% 26% 10% 2.5Min 10% -87% 48% -45% 40% 23% 10% 2.4Max 22% -89% 40% -39% 27% 18% 22% 2.8Heating Pumps  Pow. Con. (Kw) Average -2% 2% -3% 2% 1% 0% 1% 1.1Min -1% 3% -5% 3% 0% 0% 2% 1.1Max -3% 2% 1% 0% 0% 0% -1% 1.1Total Energy Consumption Rate (Kw) Average 73% -66% -38% -36% 103% -31% -5% 28.1Min 76% -71% -39% -56% 139% -40% -8% 21.8Max 67% -54% -37% -25% 67% -27% 9% 36.5Delta T: Auditorium - AmbiantAud. Temp Change Rate (deg C/h)The rate of change of the temperature of the auditorium is 1.31 degrees per hour compared to an average of 0.06  degrees per hour (It  is  18X the average rate of change. Note the average is low because there are positive and negative rates during the test period - Table 17). At  7:30am the  heating  rate  significantly  drops  down twice  slower  than  the  heating  (-0.3 degrees per hour) and classes start 1h30min beyond this time which would have given the system plenty of time to reach the required temperature more smoothly and progressively. From 9:00 to  14:00 the heating rate continues to drop which is due to the fact that the auditorium is occupied and  occupants are losing body heat (less heating is necessary from the system since occupants are doing its job unwillingly). The occupation can be noticed from the occupation curve of the testing period Air Quality Graph or the increase in the CO2 concentration level in the  Auditorium [CO2] Distribution – MAR 5.  The heating stabilizes itself when occupation is at the lowest around 100 persons and stops when the system is turned off at 22:00.As can be noticed during an experimentation day, energy consumption of the other elements of the ventilation system is pretty much constant. The total energy consumption of the ventilation system fluctuates with the addition of the heat to the supply air.Table 18 is more convenient to read when it comes to comparing the experiments with one another since it shows how much a certain parameter changes with respect to the average of all  experiments for this given parameter. Due to the formatting limitations of open office, please read the  same tables included in the appendix formatted using Microsoft words (Appendices 40 and 41). Comparing this experiment with the others. It can be seen from Table 18 that the reference day has the second highest energy consumption (73% above the overall average) after experiment 5. The reason is pretty obvious, in the reference day no energy saving measures are implemented. The reason why the system consumed more on the 5th day of experiment of this trial period is explained by the colder ambient temperature on this day by around 2.5 degrees and a superior fresh air intake forced by a 70% OA Damper opening instead of the reference 50%.The supply fan consumes the most energy on this first day (35% above average). The reason for that is unclear and cannot be isolated. In all the experiments the fan RPM is fixed to a certain value except two of them were it has been reduced by 1/3 and 2/3. The reference day will necessarily have a a consumption higher than those two experiment days but: what about the other days? The energy consumption of the supply fan is dictated by its RPM and the effort it needs to reach this RPM. The denser the air the more resistance to rotation is encountered. There are two factors affecting the density of  the air:  relative humidity and the temperature.  A combination of  both will  dictate the density of the air. Those two parameters at the level of the supply fan are dictated by some many  external factors: among those, the amount of fresh air intake, the ambient weather, the occupants and and the amount of heating occurring (and thus the SA temperature). The heating load is always maximal (in terms of amplitude multiplied by time) towards the end of the day (the sun goes down, it gets colder; the auditorium becomes vacant, no energy addition from human activity)  Page 50/74The overall behaviors of the energy curves are pretty similar (with varying rates of change and amplitudes depending on the conditions) and can be explained by the notions elaborated in this paragraph.When it comes to comparing the experiments to a normal day of operation such as on March 19 it is noticed that in all experiments during which energy saving measures were implemented the ventilation system's average power consumption is lower (Appendix 56,  values for the Total Energy  Consumption Rate  compared to 36.78 Kw average consumption observed on March 19). This is an important result because if this is the case while the environmental comfort (air quality and thermal comfort) is maintained that means that the system can further be tweaked for energy savings while on automatic mode. This will be verified in the results integration section.It is also noticed that when left on automatic, the energy consumption fluctuates much more; this is due to the variation of the damper positions letting more outside air in (and therefore requiring  more heating) or not.The main reason why the average system’s energy consumption rate is higher on March 5 than on March 19 (experimentation 1, reference day) is because the experiment was set for constant flows to be obtained 25% higher than the averages observed during normal days of operation in similar  environmental conditions.Some energy behavioral particularities will be mentioned. On March 6 (Reduced fans speed to 30% of average 24Hz and 21.6 Hz) due to a lower air circulation and thus fresh air intake, less cold air from the outside needs to be heated. This is clear  from 11:00 to 16:00 when the system is overridden. As on the reference day, from 6:30  to 7:30, the heat load peak followed by a decreasing heating rate is explained by the same reason (occupancy), even  if  some  parameters  start  to  be  fixed  starting  from 8:00.  When  the  system is  put  back  on automatic  after  16:00  the  system  reacts  abruptly  to  the  vacancy  and  thus  diminishing  internal temperature along diminishing ambient temperature (colder at night). On this day the greatest energy  savings were obtained (64% less than average) but was the air quality still within acceptable limits? Another source of energy savings:  the fans set to rotate at a lower RPM will consume much less  energy (the power is proportional to the cube of the speed!). The temperature rate of change is the  second lowest (-100%) this is due to less circulation and thus abrupt convection induced temperature changes. The system is less dynamic.On  March  7  very  roughly  70% of  the  air  was  set  to  recirculate  (30% outside  air  damper  opening). The energetic results as well as energy trends are very similar to that of the previous day's  experience. However the energy savings are not as important, the change implemented results in a 38% energy saving with respect to average. The return and supply fans consume 2nd most in between all experiments. The reason for that cannot be isolated. Page 51/74The energy behavior of the system on March 8 is very similar to that of March 6 since the occupancy  patterns  during  the  testing  period  on  those  two  days  are  alike,  (the  matching  of occupancies was made on purpose through the choice of occurrence of the experiment) ambient conditions don't change much, the major change are the fan speeds set to 2/3 of their respective average  speed  (such  as  seen  in  the  1st experiment)  instead of  1/3  in  experiment  2.  The  change implemented leads to 36% energy savings and ranks third among all measures. It is worthy to note  that this was the coldest day within the testing period, more savings could have been achieved if it was not the case!On March 9 the amount of fresh air intake was maximized with only 30% of recirculation. The day, in terms of occupancy is comparable to March 7 when fresh air intake was minimized. The energy  consumption rate is the highest among all experiments. This experiment day has the particularity of  having the most stable energy behavior, basically the systems runs all  the time at at high capacity (around  40Kw).  Because  of  the  energy  involvements,  other  energy  consideration  such  as  human generated heat load and fans power consumption become negligible. The internal temperature is very well maintained, proving the heating capacity of the system is enough for extreme conditions: not only was air in allowed at the highest rate but it was the coldest day of the testing period (along the  previous day).On March 12 the behavior of the energy curves is pretty typical of the other days, the energy savings achieved are considerable (31% of the average energy consumption for all experiments). On this day the fresh air intake was reduced to 20% mechanically but 2 out of 4 windows were opened to compensate for that by preventing a deterioration of the air quality. As will be seen in the following section of the report the air quality was preserved most of the time within an acceptable range. Apart from the experiments where the fans speeds were reduced, this experiment achieves the lowest rate of fan energy consumption. This procedure is well know in industry: in the absence of  VFDs dampers are sometimes closed to a near maximum when fans are started up to reduce the cold  start load on their driving motors (for example for an industrial heat blower like the drying machine of a pulp manufacturing company). The measure here is equivalent, it is a quasi full closing of the suction  of the fan (sometimes referred to as “suffocating the fan”). The fan has less material to push, as if it  was  turning  into  empty  space,  and  thus  encounters  less  resistance  to  rotation.  The  decreasing temperature rate of change is the highest among all experiments (-216% of average) this is most likely explained by the fact that air comes into the auditorium just above the temperature sensors (located below the windows opened).On March 12,  one can expect  a  pretty  similar  behavior  to that  of  the reference day.  The temperature set point of the auditorium was lowered by two degrees (from 21 to 19) and led to 5%  energy savings but as will be seen in the following sections, the thermal comfort can easily be affected by such a  measure. Page 52/74The FansFan consumptions and other related results are located in the table above or in the different trends  that can be found in the appendix for the different experiments.Heating of the AirDue to the high flow rate of supply air involved the heating of the air is the most energy consuming process of the system when enabled in winter.   Sometimes the heating of the air  is  not needed,  specially when the recirculation if the internal air is high and occupants are relied upon to heat the air  with their bodies. A Calculation sample is shown  as how the heating energy consumption is derived.At 12:30pm on March 5:Relative Humidity = 0.3Temperature In= 14.42Temperature Out= 19.21Flow= 3990 L/sso using equation [1] and [2] of the corresponding methodology section the enthalpy of the air prior to the coil and after the coil and its density are: hi = (1.006 kJ/kgoC)(14.42) + 0.3[(1.84 kJ/kgoC) (14.42) + (2501 kJ/kg)] = 772.76 kj/Kg ho= (1.006 kJ/kgoC)(19.21) + 0.3[(1.84 kJ/kgoC) (19.21) + (2501 kJ/kg)] = 780.23 kj/Kgρ = (1.205E-3)(1 + 0.3) / (1 + 1.609*0.3 ) =1.06E-3 Kg/LSo Qin=(1.06E-3)(780.23-772.76)=31.6 KwFurther comments and trends are made in the common sub-part of this section and other related trends can be found in the appendix. Heat RecoveryThe amount of heat recovered from the AHU2 exhaust stream could have been readily derived from the available sensors readings. This energy would have been deducted from the actual system's total energy consumption and give a better idea of its actual consumption. Unfortunately, half way through the project execution it was noted that the flow meter for AHU2 exhaust was not calibrated. Ignoring the exhaust air flow renders the knowledge of the energy extracted from the auditorium air impossible.  The  calculations  of  energy  involvement  require  precise  values  for  the  flow  under consideration or would lead to very inconsistent results, the accurate values cannot be obtained by any method in such a short notice. This parameter although considered ended up being dropped. But it was important to mention it. Page 53/74An attempt was made to obtain those results using manually measured flow with no success. However dealing with this matter pointed out the necessity of installing two sensors that can be useful for other studies involving such consideration. These are relative humidity and Temperature sensors at the HRU outlet and AHU1 outlet. d) Air Quality Assessment Results and Limitations Volatile Organic Compounds Concentration [VOCs]Figure 13: Typical Auditorium Environment VOCs Concentration Behavior – Ref. Exp. March 5Table 19: Numerical Absolute VOC Concentrations Level Analysis For Test Period 2 Page 54/74Numerical Absolute VOC Concentrations Level Analysis For Test Period 2Parameter T2:Exp1 T2:Exp2 T2:Exp3 T2:Exp4 T2:Exp5 T2:Exp6 T2:Exp7Average 0.98 0.97 1.01 1.00 0.98 1.07 1.01Min 0.97 0.97 0.97 0.98 0.97 0.97 0.99Max 0.99 0.97 2.13 1.92 1.00 1.16 1.77Average 0.00 0.00 -0.17 -0.01 0.00 -0.03 0.11Min -0.05 -0.01 -3.47 -0.13 -0.08 -0.58 0.00Max 0.00 0.00 0.00 0.00 0.00 0.00 2.34[VOCs] Auditorium [VOC] in ppmAverage [VOC] Change Rate (ppm//h)0:00 6:00 12:002:00 4:00 8:00 10:00 14:00 16:00 18:00 20:00 22:000.000.501.001.502.002.50Auditorium Air Quality - MAR 5[VOC] Critical [VOC] Concentration [ppm]The assessment of the adequacy of the ventilation system, in terms of preserving the living space provided by the auditorium from dangerous levels of VOCs concentrations, can be done in a very  straight  forward  fashion.  A  quick  look  at  the  different  Air  Quality  graphs  included  in  the appendices can show if  whether critical  VOCs level  are reached to what  extent and when. Some explanation are provided. With regards to this matter, the following conclusion can be drawn from the relevant literature review: No  standards  have  been  set  for  VOCs  in  non  industrial  settings.  In  fact,  a  recent  review concluded that no scientifically  valid  guidance could be given with respect to indoor TVOC levels (Anderson et al., 1997). There are thousands of VOC compounds. Some of the compounds have been recognized as a specific health risk and have specific guidelines. An example of such specific guideline: The Occupational Safety and Health Administration (OSHA) regulates formaldehyde, a specific VOC, as a carcinogen; it has therefore a Permissible Exposure Level (PEL) of .75 ppm, and an action level of 0.5 ppm. For BC, some of those guidelines for specific compounds (or groups of compounds) can be found in Exposure Guidelines for Residential Indoor Air Quality; A Report of the Federal-Provincial Advisory Committee on Environmental and Occupational Health. There are, however, possible benefits to be derived from keeping exposures to airborne contaminants “As Low As Reasonably Achievable.” This ALARA principle suggests that indoor concentrations of VOCs in residences should not exceed levels typically encountered in the housing stock (ECA-IAQ, 1997). The database of TVOC concentrations in residences is limited, and many of the methods used to quantify TVOC are not directly comparable (Hodgson, 1995). Nevertheless, the reported TVOC concentrations for various indoor environments are frequently about 1 mg/m3, or lower (Brown et al., 1994).For the CIRS auditorium a value of 2ppm is chosen as a threshold of VOC concentration that is not to  be exceeded; this  value is  arbitrary and results from common practice rather than solid scientific  evidences. An example of such common practice: when the USEPA built their own building, they used a Maximum Allowable Air Concentration Standard of <0.20 mg/m3 Total Volatile Organic Compounds (TVOCs).Looking at those graphs some major observations can be made:• The VOCs concentration are independent of the auditorium occupation level during the testing period. • Critical Levels of VOCs concentration are never reached when the auditorium is occupied.• VOCs levels are pretty stable along the day, no significant fluctuations are recorded.• A VOC concentration surge is recorded everyday during the start-up of the ventilation system that last for one to two hours. Page 55/74The first observation is quite surprising since it  was expected that the VOCs concentration would behave in the same way the CO2 concentration would. The reason for this not happening is worth investigating in further studies. Even by increasing the resolution of the trends, no elevation of  VOCs concentration was spotted at time of high occupancy as was noticed for the CO2 concentration. However an expected behavior of the VOCs concentration levels was observed on March 21 and 22 where it can be clearly seen that they vary along occupancy. At night the ventilation system is turned off  and the dampers, in closed positions, prevent outside  air  from infiltrating  the  auditorium.  Apart  from very  minor  air  leaks,  air  circulation  and renewal is negligible. VOCs emanate from various elements within the auditorium (or any system), such as the paint of the walls and other furniture, the plastic of some electrical devices, the seats lining and many other objects...  The absence of air circulation/renewal allows the VOCs to build up  within the auditorium. The VOCs diffuse within the auditorium with unknown  uniformity. The VOCs sensor is located within the return/exhaust duct of the ventilation system. The stagnation of the air is  a  such that  the sensor  does  not  detect  the  diffusing  VOCs.  As  soon as  the  ventilation  system is activated air is sucked from within the room, in other words the VOCs spread all over the auditorium is gathered by the suction forces, forced into the return duct and therefore detected by the sensor. The sensor will keep on detecting high levels of VOCs up until most of it has been cleared out from the  space. The clearing of the auditorium from VOCs will occur progressively depending on the fresh air intake and fans speed. Until  the clearing occurs, the levels of VOCs can be deemed unsuitable for  human presence. An individual and detailed  assessment of each experiment is not necessary but an overview will be made along some comments.• On March  5 and 13, a very typical behavior is observe: all criterion described above are met.• On March 6, 8 and 9 all criterion described above are met but another surge is observed at  night though the ventilation system is turned off.• On March 7 all  criterion described above are  met but  another  surge is  observed at  night  though the ventilation system is turned off. The start-up surge is followed by another one. The reason behind the double surge has not been identified. The critical VOCs level is reached and occupants  have most  likely  (one cannot  claim this  due to a  limitation that  is  going  to  be mentioned later on  in this section), on that day, been very briefly exposed to critical a VOC  level (2ppm at 9:00). The fresh air intake reduced to a minimum have prevented an adequate  renewal of the air within the auditorium prior to occupation. On this day the highest positive rate of change of VOCs concentration levels is detected among all experiments (50% above average),  in other words the quickest VOC buildup in the return duct during the activation phase of the ventilation system. Air passes through the duct at a normal rate (the fan speeds are normal) but nearly all the air comes from the auditorium and very little from outside. Page 56/74• On march 12 an unusual behavior of the VOCs concentration level is observed. There is the usual start-up surge but the concentration drops to a higher than usual level, is maintained for about 5hours before reaching the usual value of about 1ppm. On this day the mechanically driven fresh air intake has been reduced to a maximum and two windows were open. The rate of  removal  of  VOC through the exhaust duct is  minor,  a  big  part  of  it  occurs through the windows where there is no sensor. Why this steady state was reach is hard to justify. While the main requirement (critical level never reached during occupancy)can be deemed as met there are several limitations to this kind of analysis and the reliance of this one sensor located in the return air duct:• Not detected doesn't mean not present: The fact that the sensors is located a bit far away from the  auditorium  does  not  mean  there  are  actually  no  VOCs  present.  The  buildup  can  be concentrated in the center of the room and not reach the sensor up until air is forced in the return duct. • Uniformity not measured: Due to the presence of only one sensor, the distribution of the VOCs (contrary to that of the CO2) is unknown.  One cannot guarantee that if high VOCs level are not detected by the sensor that means there are no high VOCs level. To illustrate this claim, let us imagine several VOC emitting elements (such as a paint aerosols) are carried by a student in his backpack for use after school and introduced in the auditorium. A local region in his very near  surrounding will be subject to a higher VOCs level to that of the auditorium but will remain undetected.• Exposure to high concentration:  As has been seen in all experiments, the VOC buildup in the auditorium needs time to be cleared out and before steady state is reached. Unless the start up time is adequately chosen, occupants may be exposed to high VOCs levels.• Unidentified  sources  of  VOCs:  In  several  experiments,  unexplained  VOC  surges  occurred throughout the night despite the system being shut off. The system may not react fast enough to a random and unpredicted introduction of a VOC emitting element. Page 57/74Carbon Dioxide Concentration [CO2]The critical CO2 concentration for the auditorium is considered to be 1000 ppm. This arbitrary value comes from the wide belief in building management that this is a common practice supported by Ashrae.  The ventilation system itself  is  set,  as  can be seen in  the control  strategy section,  to maximize the fresh air intake to 100% when the differential CO2 concentration between the inside and the atmosphere exceeds 750 ppm. Given an average of 400 ppm of ambient CO2 concentration that is equivalent to a 1150 acceptable indoor CO2. It is widely reported by the technical community involved in indoor air evaluations that the American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE) has a standard of 1,000 ppm  CO2  for  indoor  spaces.  The  Standard  often  cited  is  ANSI/ASHRAE  62-1989  “Ventilation  for Acceptable Indoor Air Quality” (which has since been replaced by ANSI/ASHRAE 62-1999). However, this interpretation is incorrect; the current ASHRAE Standard “Ventilation for Acceptable Indoor Air Quality” (ANSI/ASHRAE 62-1999) does not reference the term “1,000 ppm CO2.” (Petty, 1989).The fist limitation of relying on such a critical value in assessing the adequacy of the air quality and for  building management purposes is that the CO2 level of 1000 is a guideline for comfort acceptability, not a ceiling value for air quality, it is used as a surrogate for odor causing compounds from human activity that may not be acceptable for human comfort.The  Acceptable  Short-Term  Exposure  Range  indoor  CO2 concentration  mentioned  by  Exposure  Guidelines for Residential Indoor Air Quality is 3500 ppm.In  previously  published analyses  of  the  41-building  1994-1996  USEPA Building  Assessment Survey  and Evaluation (BASE)  data-set,  higher  workday  time-averaged indoor  minus outdoor  CO2 concentrations (dCO2), were associated with increased prevalence of certain mucous membrane and lower respiratory sick building syndrome (SBS) symptoms, even at peak dCO2 concentrations below 1,000 ppm (Erdmann, C. A., Steiner, K. C., & Apte, M. G. ,2002). This statement confirms the limitation of such a reliance. On top of this SBS and mucus problems related to indoor CO2 concentration are  dependent  on  many  factors  such  as  age,  sex,  smoking  status,  presence  of  carpet  in  workspace,  thermal exposure... Page 58/74Figure 14: Typical Auditorium Environment CO2 Concentration Behavior – Ref. Exp. March 5 Page 59/740:00 6:00 12:002:00 4:00 8:00 10:00 14:00 16:00 18:00 20:00 22:000.00200.00400.00600.00800.001000.001200.00Auditorium [CO2] Distribution - MAR 5[CO2] - RA[CO2] - NE[CO2] -NW[CO2 ] - SE[CO2] - SWAvg. [CO2] Ambient - [CO2]Critical [CO2][CO2] ppmTable 20: Numerical Absolute CO2 Concentrations Level Analysis For Test Period 2An overview of the behaviors of the CO2 concentrations for the different experiments will be made along some supporting explanations. Two factors will be considered: the first one being whether critical levels are reached, the second will be an assessment of the uniformity of the CO2 distribution  within  the  auditorium.  Two  elements  can  help  spot  non  uniformity:  a  significant  separation  in between the curves generated from the data of the different sensors (graphs), a significant deviation from the average uniformity with respect to the other experiments (from the corresponding tables,  the “total” average-min-max).On  March  5,  the  CO2  concentration  levels  behavior  is  pretty  typical:  piling  up  with  the successive occupancy of the auditorium. The reference experiment has the best uniformity and air mixing among all experiments after experiment 5.  Page 60/74Numerical Absolute CO2 Concentrations Level Analysis For Test Period 2Parameter T2:Exp1 T2:Exp2 T2:Exp3 T2:Exp4 T2:Exp5 T2:Exp6 T2:Exp7Average [CO2] Change Rate (ppm/h) Average 2 74 17 40 2 13 8Min -271 -446 -333 -395 -144 -450 -356Max 274 526 405 600 113 455 405Average Auditorium [CO2] Average 574 940 762 723 512 741 649Min 429 423 472 451 463 496 440Max 761 1329 1053 994 577 1035 734Delta [CO2]: Auditorium – Ambient Average 162 507 246 241 43 332 203Min 11 -22 0 -25 -30 84 -50Max 353 904 564 524 108 629 322Delta [CO2]: NW - Auditorium Average 8 -62 1 -32 -3 -5 -10Min -15 -137 -19 -86 -21 -25 -32Max 70 52 34 27 18 34 28Delta [CO2]: NE - Auditorium Average -8 -64 -14 -31 -7 -7 -19Min -71 -148 -64 -89 -29 -29 -44Max 11 36 6 27 5 14 18Delta [CO2]: SW - Auditorium Average 17 187 32 96 22 25 56Min -15 -80 0 -12 3 -2 -7Max 107 411 126 254 93 83 119Delta [CO2]: SE - Auditorium Average -16 -61 -19 -34 -12 -13 -27Min -79 -157 -70 -91 -43 -39 -52Max 3 22 3 8 -1 -1 10Delta [CO2]: RA - Auditorium Average 27 -165 -146 -45 71 -92 19Min -18 -312 -350 -286 -13 -305 -36Max 72 8 24 47 137 40 58Total Average 6 -31 -30 -16 15 -21 5Min -79 -312 -350 -286 -43 -305 -52Max 107 411 126 254 137 83 119A  way  to  see  this  is  noticing  that  at  most  the  absolute  level  in  concentration  in  between  the auditorium sensors is 107ppm while the average is 6ppm. On March  6  the low supply and return ventilation rates (1/3 of normal ventilation rate) do not allow a proper clearing of the CO2 generated by the students and a proper mixing in the auditorium.  The highest non uniformity is witnessed during this day with a 411ppm difference between two of the  auditorium sensors and among the highest averages of CO2 concentration difference between sensors (411ppm). The piling up of CO2 rate is the second highest among all: 526ppm/hour. High clearing rates are only observed when the system is put back on automatic when the critical CO2 concentration level has  been reach  and  is  therefore  not  representative  (-446ppm/hour)  of  the  experiment  itself.  On March  12  one  can  observe  similar  behaviors  since  the  measures  undertaken  are  equivalent  (a reduction of the fresh air intake) despite different occupancies. On March 7 the low fresh air intake (70% recirculation) also leads to the critical concentration of CO2 being reached around mid-day but can be deemed acceptable. Surprisingly the return air has much lower concentration levels than the auditorium average despite that the air is properly mixed. This should be understood but no explanation can be thought of with a more in depth study of the matter. On March 8 and 13 two CO2 concentration domes are  observed on the graphs.  They are separated by a certain low occupancy or vacancy period of the auditorium where the system had time to clear out the excess CO2. Uniformity is good apart from a deviation of the SW sensor on March 8. On March 9, the fresh air intake is maximized, the CO2 barley piles up in the auditorium, the critical level is far from being reached at any point of the auditorium. The uniformity is excellent. The system was put back on automatic after 16:00 an event provoking an unknown occupancy of the auditorium explains the second CO2 dome on the graph.The auditorium CO2 level behavior observed on march 13 is different that the one observed on march 5 despite the similarity in the controlled parameters (the temperature set-point change does not affect CO2 levels in any way). The reason behind this difference is the varying occupation patterns  for both days that are a huge factor in determining how the CO2 builds up in the auditorium.  Page 61/74e) Thermal Comfort  Assessment Results and LimitationsCIRS Auditorium  Thermal Comfort Assessment Table At 1.0 CloFrom To 03/05/12 03/06/12 03/07/12 03/08/12 03/09/12 03/12/12 03/12/1209:00 09:30Occupancy: 133RH: 30.4%Temperature: 20.4Occupancy: 133RH: 24.3Temperature: 20.6Occupancy: 133RH: 37.3Temperature: 20.5Occupancy: 133RH: 30.4Temperature: 20.409:30 10:00Occupancy: 255RH: 22.3%Temperature: 19.8Occupancy: 255RH: 25.3Temperature: 20.5Occupancy: 255RH: 29.7Temperature: 19.310:00 10:30Occupancy: 257RH: 30.2%Temperature: 20.5Occupancy: 257RH: 25.4%Temperature: 20.6Occupancy: 257RH: 38.9Temperature: 20.6Occupancy: 257RH: 30.2Temperature: 20.510:30 11:0011:00 11:30Occupancy: 202RH: 29.5%Temperature: 20.6Occupancy: 227RH: 23.3%Temperature: 20.5Occupancy:202RH: 35.36%Temperature: 21.50Occupancy: 227RH: 27.1Temperature: 20.8Occupancy: 202RH: 39.3Temperature: 20.7Occupancy: 202RH: 29.5Temperature: 20.6Occupancy: 227RH: 31.6Temperature: 19.411:30 12:0012:00 12:30Occupancy: 336RH: 28.8%Temperature: 20.8Occupancy: 336RH: 27.6%Temperature: 207Occupancy: 336RH: 40.9Temperature: 20.7Occupancy: 336RH: 28.8Temperature: 20.812:30 13:00Occupancy: 149RH: 24%Temperature: 21.1Occupancy: 149RH: 32.6Temperature: 19.413:00 13:30Occupancy: 371RH: 28.1%Temperature: 20.8Occupancy: 371RH: 29%Temperature: 20.8Occupancy: 371RH: 40.7Temperature: 20.7Occupancy: 371RH: 28.1Temperature: 20.813:30 14:0014:00 14:30Occupancy: 135RH: 25.5%Temperature: 20.6Occupancy: 316RH: 24.1Temperature: 21.4Occupancy: 135RH: 28.8%Temperature: 20.7Occupancy: 316RH: 28Temperature: 20.6Occupancy: 135RH: 40.5Temperature: 20.7Occupancy: 135RH: 25.5Temperature: 20.6Occupancy: 316RH:33.7Temperature: 19.514:30 15:0015:00 15:30Occupancy: 103RH: NaTemperature: Na15:30 16:0016:00 16:3016:30 17:00Table 21:  Thermal Comfort Assessment Over Testing Period Note: Green = Well Within Comfort Zone; Yellow = Comfort Zone Borders/Acceptable; Red=Off comfort Zone Page 62/74Table 22: Thermal Comfort Uniformity Within The Auditorium Analysis Page 63/74Results: Differences Analysis – Thermal Comfort Uniformity IndicatorParameter T2:Exp1 T2:Exp2 T2:Exp3 T2:Exp4 T2:Exp5 T2:Exp6 T2:Exp7TemperatureAverage Audi torium Temperature Average 20.5 20.5 20.6 20.8 20.6 20.8 19.2Min 20.1 20.5 20.5 20.3 20.3 20.6 19.2Max 20.6 20.5 20.9 21.3 20.7 20.9 19.2Del ta T: NW - Audi torium Average 0.3 0.4 0.3 0.3 0.3 0.2 0.5Min 0.2 -0.8 0.0 -0.1 0.2 0.1 0.0Max 0.7 0.9 0.8 0.7 0.6 0.5 0.9Del ta T: NE - Auditorium Average 0.1 0.3 0.0 -0.2 -0.1 -0.4 0.1Min -0.3 -1.1 -0.3 -0.6 -0.2 -0.6 -0.2Max 0.4 1.1 0.1 0.2 0.2 -0.2 0.3Del ta T: SW - Auditorium Average 0.3 0.9 0.1 0.5 0.1 0.1 -0.1Min -0.2 -0.9 -0.3 -0.4 0.1 -0.1 -0.5Max 1.3 1.7 0.4 1.4 0.5 1.1 0.3Del ta T: SE - Auditorium Average -0.2 0.0 -0.1 -0.3 0.0 -0.3 0.1Min -0.4 -1.2 -0.4 -0.7 -0.1 -0.4 -0.1Max 0.1 0.8 0.1 0.1 0.3 0.0 0.1Del ta T: SA - Audi torium Average -0.7 -2.1 -1.2 -2.1 -1.0 -1.4 -3.2Min -2.8 -6.3 -3.2 -6.1 -1.9 -4.1 -5.6Max 1.2 2.8 0.4 1.7 0.3 -0.1 -1.7Del ta T: RA - Auditorium Average 1.5 1.4 1.4 1.0 1.3 1.1 1.9Min 1.0 -0.4 1.0 0.5 0.8 0.4 1.0Max 2.0 2.6 1.9 1.8 1.8 2.0 2.4Tota l  Average 0.24 0.00 0.06 -0.12 0.18 -0.11 -0.21Min -2.79 -6.34 -3.23 -6.05 -1.85 -4.06 -5.55Max 2.03 2.80 1.91 1.77 1.80 1.99 2.45Average Audi torium Relative Humidi ty Average 27.9 23.7 26.9 28.2 39.6 35.1 32.4Min 22.0 22.0 23.4 24.6 36.3 30.5 28.7Max 31.0 24.9 29.6 32.0 41.4 38.6 34.0Relative HumidityDelta RH: NW - Audi torium Average -0.4 -1.1 -0.4 -1.2 -0.5 -1.3 -0.2Min -1.1 -2.2 -1.3 -2.6 -1.7 -2.5 -1.2Max 0.1 0.5 0.1 0.1 0.0 -0.4 0.3Del ta RH: SW - Audi torium Average -0.2 1.8 0.1 0.7 0.1 0.3 0.2Min -0.7 0.0 -0.4 -0.3 -0.5 -0.2 -0.3Max 0.3 3.5 0.7 1.6 0.8 1.6 0.8Del ta RH: SE  - Auditorium Average 0.7 -0.6 0.3 0.5 0.4 1.0 0.0Min 0.0 -1.5 -0.2 -0.6 -0.3 0.3 -0.5Max 1.4 0.2 1.0 1.6 1.4 1.9 0.9Del ta RH: SA - Audi torium Average 0.7 4.0 1.8 4.8 2.8 3.5 6.7Min -2.5 -6.2 -1.2 -2.2 0.2 0.3 2.8Max 4.2 15.5 5.4 13.6 5.5 9.2 8.9Del ta RH: RA- Audi torium Average 2.2 -0.3 -3.1 -0.2 -0.2 -1.4 -1.2Min 0.8 -1.5 -5.5 -2.7 -1.2 -3.8 -2.2Max 4.2 1.2 -0.3 1.5 0.7 0.7 1.0Tota l  Average 0.6 0.9 -0.2 1.0 0.5 0.6 1.1The  thermal  comfort  assessment  follows  the  method  described  in  the  corresponding methodology section. This is quite a rough estimate, specially that the concept of thermal comfort is ambiguous  and  subjective.  According  to  the  standards  previously  stated,  most  of  the  time,  the comfort levels achieved in the auditorium are deemed just acceptable. A raise of two degrees Celsius set point would guarantee thermal comfort according to those standards given relative humidity of  20% to 30.5%.Depending on the uniformity of the relative humidity and temperature distribution and their combination some locations within the auditorium may easily fall outside the comfort zone.Other parameters not taken into account do also greatly affect how a person feels when using a given space: the vertical temperature gradient which in this case is not assessed. For the sake of reference an example will be sited: On the second experimentation day of the trial  period  2,  the  greatest  temperature  difference  between  the  SW  sensor  and  the  average auditorium temperature is 1.7 degrees. While the time of occurrence of this difference is not known (but could be) whenever it falls within the day it would drift the thermal comfort results way out of bonds. Page 64/74V- Results Integration, Energy Savings and Optimization RecommendationsThe essence of this analysis is to show that even on automatic there is still a possibility of energy savings through measures  that do not hinder the livability/comfort of the auditorium space.Figure 15: CIRS Energy System DiagramThe CIRS is a complex energy system of which description can be found on the CIRS official site:  “Multiple  systems  work  together  to  serve  the  different  needs  in  the  building  and  use  energy efficiently.  A heat  recovery system captures  waste  heat  in the exhaust  ventilation from the fume hoods on the adjacent Earth and Ocean Sciences (EOS) building and transfers it to the heat pumps in CIRS. The heat pumps provide heating and cooling for the building through the radiant slabs and a  displacement ventilation system. The energy exchange system returns excess heat from the CIRS heat pumps to EOS, which reduces its heat load and the demand on the campus steam system. The amount of energy in the heat transferred to EOS is greater than the total amount of energy consumed in CIRS.  A ground source geo-exchange field supplements the waste heat recovery and provides heating and cooling to the pumps. An evacuated tube array on the roof that captures solar energy and an internal  heat recovery system that captures waste heat from the building systems preheat the domestic hot water.  Photovoltaic cells on the atrium roof and the window sunshades convert solar energy into electricity.” Page 65/74Figure 16: Ventilation System Energy DiagramDepending  on  the  choice  of  the  system  and  its  boundaries,  estimating  the  savings  and environmental impact can be a very difficult task. The AHU under consideration involves 3 types of  energy:  direct  electrical  (fans  and  pumps),  indirect  electrical  (heat  pumps:  the  thermal  energy extraction is supported by the compression of the refrigerant which consumes electricity) and thermal  (HRU). The energy recovered from the air handling unit is dependent on whether it is needed (the recovery is automatically bypassed otherwise) by the various systems intended to be receiving it. The energy input (and paid for) to heat up the air,  is dependent on the coefficient of performance of the heat pump.  Page 66/74The coefficient of performance is dependent on the the temperature difference between the two thermal reservoirs exchanging heat. One of the thermal reservoirs, the EOS building, from which the  heat  pump extract  heat  is  highly  variable  (mainly  due  to  its  varying  occupancy  and  energy  demand). The fans and pumps draw energy which is either supplied by BC Hydro through the UBC grid or by the photovoltaic system installed. The amount of energy paid for is dependent on how much solar power is recovered and therefore the ambient conditions. Most of the energy (90% of it) is supplied by BC Hydro. 90% of BC Hydro's generated electricity is from Hydro power, but given the fact that BC Hydro continuously import (from various origins, fossil and non-fossil) and exports electricity, the actual carbon savings would be hard to precisely predict. Further clarification will be made to help read the following table, assumption will be stated and system boundary defined:-The system boundary is illustrated in figure 16 by a yellow line, it includes the AHU2.-The total energy consumption and savings is both thermal and electrical, it is an aggregate value that  includes the thermal energy into the supply air stream, The SF and RF and heating pump electrical  consumption.-The energy being dealt with is absolute and not representative of the energy that is actually paid for (not all the energy inputted to the supply air is paid for due to the COP of the heat pump).-The reference day is assumed to be representative of a normal day of operation although some control parameters were overridden and fixed*. -Energetic  operating costs  are  derived from the average power consumptions  measured during  a whole daily period of interest (9am to 4pm) for the different systems mentioned for each experiment. -Savings  are  obtained  by  comparing  each  experiment  to  the  reference  day.  Setting  the  system's parameter  such  as  done  in  the  experiments  does  not  guarantee  the  same  savings  as  they  are dependent on many other factors such as ambient conditions, auditorium occupation etc...-The savings are not adjusted based on outside conditions of temperature and relative humidity. In other words if a hotter day will result in additional savings that are not originating from the control measures taken although expressed by the numerical figures.-The number given in this analysis are very rough estimates for the sake of illustration and support. In no way are those result claimed to be accurate but rather they are indicative of certain potentials and tendencies aimed at motivating changes in the system's control.-The energy recovered in the HRU is disregarded since outside of the system boundaries chosen. Page 67/74*While  it  is  true  that  even  on  the  reference  day  some  parameters  were  fixed  (to  reduce  the  variability  preventing  comparison) the reference day is still representative of a normal operating day where the system is set to automatic. This is  because the fixed parameters are assigned values that are nothing but the average of the respective parameters over a  day on automatic mode.  Reference Day Experiment 2 Experiment 3 Experiment 4Modification None 65% Fan Speed Reduction 40% Fresh Air Intake Reduction35% Fan Speed ReductionAverage Power Consumption [Kw]48.5 9.5 17.5 18Energy Consumption (over 860h*(1)) [Kwh]41710 8170 15050 15480Estimated Energy Savings Potential % w/r to ref.0% 80% 64% 63%Estimated Energy Savings Potential w/r to ref (Kwh over 860h)0 33540 26660 41692Estimated Energy Savings Potential % w/r to Auto. Day 1-31% 74% 53% 51%Estimated Energy Savings Potential  w/r to Auto. Day 1 (Kwh over 860h)-9890 23650 16770 16340Air Quality Assessment - VOCsVOCs  concentrations  levels remained  below  the  critical value at all time.Max [VOCs] = 0.99 ppmVOCs  concentrations  levels remained  below  the  critical value at all time.Max [VOCs] = 0.97 ppmMinor/brief  exposure  of student  to  critical  VOCs concentration levels.Max [VOCs] = 2.13 ppmVOCs  concentrations  levels remained  below  the  critical value at all time.Max [VOCs] = 1.92 ppmAir Quality Assessment - CO2CO2  concentrations  levels remained  below  the  critical value at all time.Max [CO2] =761 ppmProlonged exposure to above critical CO2 levels at a certain point during the experimentMax [CO2] =1329 ppmBrief  exposure  to  above critical CO2 levels at a certain point during the experimentMax [CO2] =1053 ppmCO2  concentrations  levels remained  below  the  critical value at all time.Max [CO2] =994 ppmThermal Comfort AssessmentRH: 30.2% Temperature: 20.5 from 10am to 11amRH: 22.3% Temperature: 19.8 from 10am to 11amRH: 25.4% Temperature: 20.6 from 10am to 11amRH: 25.3% Temperature: 20.5 from 10am to 11amFeasibility Yes No Yes YesRecommendations Increase temperature set point by 2 degreesDecrease Fan Speeds Less DrasticallyA 25% to 30% fresh air intake reduction would be advisedImplement but Increase temperature set point by 2 degreesTable 23: Experiments Outcome Summary 1 Page 68/74Reference Day Experiment 5 Experiment 6 Experiment 7Modification None 40% Fresh Air Intake Increase 60% Fresh Air Intake Reduction + 50% Window OpeningTemperature Set Point Decrease by 2 degreesAverage Power Consumption [Kw]48.5 57 19.5 27Energy Consumption (over 860h*(1)) [Kwh]41710 49020 16770 23220Estimated Energy Savings Potential % w/r to ref.0% -18% 60% 44%Estimated Energy Savings Potential w/r to ref (Kwh over 860h)0 -7310 24940 41683Estimated Energy Savings Potential % w/r to Auto. Day 1-31% -54% 47% 27%Estimated Energy Savings Potential  w/r to Auto. Day 1 (Kwh over 860h)-9890 -17200 15050 8600Air Quality Assessment - VOCsVOCs  concentrations  levels remained  below  the  critical value at all time.Max [VOCs] = 0.99 ppmVOCs  concentrations  levels remained  below  the  critical value at all time.Max [VOCs] = 1.00 ppmVOCs  concentrations  levels remained  below  the  critical value at all time.Max [VOCs] = 1.16 ppmVOCs  concentrations  levels remained  below  the  critical value at all time.Max [VOCs] = 1.77 ppmAir Quality Assessment - CO2CO2  concentrations  levels remained  below  the  critical value at all time.Max [CO2] =761 ppmCO2  concentrations  levels remained  below  the  critical value at all time.Max [CO2] =577 ppmBrief  exposure  to  above critical CO2 levels at a certain point during the experimentMax [CO2] =1035ppmCO2  concentrations  levels remained  below  the  critical value at all time.Max [CO2] =734 ppmThermal Comfort AssessmentRH: 30.2% Temperature: 20.5 from 10am to 11amRH: 38.9% Temperature: 20.6 from 10am to 11amRH: 30.2% Temperature: 20.5 from 10am to 11amRH: 29.7% Temperature: 19.3 from 10am to 11amFeasibility Yes Unnecessary Yes NoRecommendations Increase temperature set point by 2 degreesFresh air increase is only advised momentarily when critical levels of air quality are reachedThis measure can be resorted to but leads to less uniformity. The temperature is not recommended to be decreased. Table 24: Experiments Outcome Summary 2*(1)860 hours  represent  the  approximate amount  of  hours  that  the  ventilation  system is  active  during  one  academic  semester (4 month, 5 days a week, 10 hours a day)The green color indicates that the measure implemented to reasonable extents shouldn't be source of concern when it comes to the adequacy of a certain parameter. The yellow color indicates that the conditions were still overall acceptable according to criteria with minor exceptions but may drift away if some conditions that are not  controlled favor the drift. The orange color shouldn't be source of worrying, but rather an indication that extra attention should be given when interpreting the results  and  the  limitations  should  clearly  be  identified  in  order  not  to  classify  an  acceptable environment as bad one. A very simple modification can drastically affect the result: For example in experiment 3 the orange color should not be interpreted as indicative of a big problem that makes the  measure (the reduction of fresh air intake non viable) non viable.  Page 69/74A slight increase in the temperature set point would make the conditions adequate according to  the  criterion  followed  for  thermal  comfort  while  not  hindering  too  much  the  energy  savings obtained thanks to the measure implemented.Overall, the results show that saving measures can be implemented through the tweaking of the control algorithm linking the different parameters of the ventilation system.The results of experiment revealed some drifting with regards to the CO2 and thermal comfort criteria, it wouldn't be recommended to set the system to obtain such a low air circulation despite the appealing  energy  savings.  A  less  drastic  measure  implementation  similar  to  this  one  is  seen  in  experiment 4 would be recommended. In other words modify the control parameters of the system in such a way that the average circulation flow is decreased. Experiment 3 is comparable to experiment 4 when it  comes to energy savings,  while  not  too bad when it  comes to environmental  adequacy. However the results should be interpreted as such that if the choice is available one should rather opt for the decrease in circulation. Experiment 6 shows that opening windows can be a good substitute to mechanically forcing outside air in it is a less severe measure that the one adopted in experiment 3  and makes it more feasible. Experiment 7 is representative of the order of magnitude of savings one would  obtain  by  decreasing  the  temperature  set  point.  The  deviation  from the  thermal  comfort criterion does not indicate that such measure is inadequate, but rather that the temperature set point  was already appropriately chosen and didn't need further modification.One should be careful when reading and interpreting those results. As has been previously discussed there are limitations to relying on solely those criteria and methodologies. The table simply  summarizes what was observed, more through interpretations of the results will be subject to fallacies  and therefore left to the reader's discretion. To illustrate what has been said some example are taken. For experiment 3, at some point during the day, the conditions were such that when plotted on a psychometric chart the point fell outside the comfort box defined by Ashrae. The experiments fail to  pass this specific criteria but does that mean the environment is inadequate when it comes to CO2 concentrations? Not really because the criteria has a lot of limitations and the methodologies relied upon are broad.  What  the criteria  aim to achieve is  to guarantee in certain ways that  if  the the conditions  are  such  that  the  criteria  are  met  it  is  most  likely  that  the  conditions  should  not  be perceived by an overwhelming majority of people as problematic.  Page 70/74VI- ConclusionThe  study  has  shown the  advantages  of  dealing  with  a  modern  ventilation  system.  Some defects were identified and attention was drawn to motivate their repair. Through this study, it has  been verified that criteria of comfortable living space are met by the environment of the auditorium thanks to its supporting ventilation system. Despite the fact that simple criteria were relied upon the result are meaningful.  The various experiment performed, most of which led to energy savings, have shown that a tweaking of the ventilation system is possible without hindering the livability of the  environment  provided  by  the  auditorium.  Overall  it  was  concluded  that  tweaking  the  control algorithm of the ventilation system in a way to obtain 10% less circulation flow is recommended. This measure  will  not  hinder  the  livability/comfort  of  the  auditorium's  environment.   The  important findings of this study are summarized in the executive summary and will  not be presented in this section to avoid redundancy.VII- Project SignificanceThe project reveals the importance of investing into advanced and modern ventilation systems: most of the study was made possible thanks to the on-site sensors monitoring its functioning. The flexibility of the system was taken advantage of in a way that the system was tweaked in order to  obtain energy savings while maintaining the comfort of the living space; and this is what the project partially aims to motivate. Given the fact that a building's ventilation system consumes about a 1/3 of  its total energy requirements, any energy saving achieved at this level would be significant. The world is  heading towards  sustainability  through generation of  electricity  from clean energy sources and conservation. The energy savings promoted by this project fall in the category of conservation and can motivate such energy saving measures implementation in the management of other buildings. It is  therefore in total accordance with the higher objectives of this masters program. Page 71/74VIII- References1]Christopher Y. Chaoa, M.P. Wana, Anthony K. Lawb. Ventilation performance measurement using constant concentration dosing strategy.[2]  http://www.energymanagertraining.com,  PDF document:  The importance of energy efficiency in buildings.[3] World  Business  Council  for  Sustainable  Development,  Energy  Efficiency  in  Buildings  Summary Report.[4] Sherman MH, Matson N. Residential ventilation and energy characteristics.ASHRAE Transactions 1997;103:717–30.[5] Emmerich SJ, Persily AK. Energy impacts of infiltration and ventilation in U.S.Office buildings using multizone airflow simulation. In: Proceedings of IAQand energy, New Orleans, LA; 1998. p. 191–203.[6] Bearg DW. Indoor air quality and HVAC systems. Boca Raton, FL: Lewis Publishers; 1993.[7] Andrew  K.  Persily,  Manual  for  Ventilation  Assessment  in  Mechanically  Ventilated  Commercial Buildings[8] ASHRAE, 1989, Ventilation for Acceptable Indoor Air Quality, Standard 62-1989, American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc., Atlanta..[9] ASHRAE,  1992,  HVAC  Systems  and  Equipment  Handbook,  American  Society  of  Heating, Refrigerating and Air-Conditioning Engineers, Inc., Atlanta.[10] ASHRAE,  1993,  Fundamentals  Handbook,  American  Society  of  Heating,  Refrigerating  and  Air Conditioning Engineers, Inc., Atlanta.[11]  W.M.P. (Jeffry) van der Pluijm, The Robusten and Effectiveness of Mechanical Ventilation in Air-Tight Dwellings[12] Rim, D., & Novoselac, A. (2010). Ventilation effectiveness as an indicator of occupant exposure to particles  from  indoor  sources.  Building  and  Environment,  45(5),  1214-1224.  Elsevier  Ltd. doi:10.1016/j.buildenv.2009.11.004[13] Petty, S. (1989). SUMMARY OF ASHRAE’S POSITION ON CARBON DIOXIDE CO2 LEVELS IN SPACES. Refrigeration And Air Conditioning.[14] Unknown  Author.  The  Importance  of  Energy  Efficiency  in  Buildings.  The  Bulletin  on  Energy  Efficiency, 6(4-6).[15] Federal Energy Management. (n.d.). Demand-Controlled Ventilation Using CO 2 Sensors. Energy. Page 72/74[16] European Consumer Protection Commission. (2003). Environment and Quality of Life Ventilation ,  Good Indoor Air Quality. Indoor Air.[17] Apte, M. G. (2006). A Review of Demand Control Ventilation. Ashrae Standard, (May).[18] Memarzadeh,  F.,  &  Manning,  A.  (n.d.).  Thermal  Comfort  ,  Uniformity  ,  and  Ventilation Effectiveness in Patient Rooms : Performance Assessment Using Ventilation Indices. Assessment.[19] Dunn, W. A., Brager, G. S., Brown, K. A., Clark, D. R., Deringer, J. J., Hogeling, J. J., Int-hout, D., et al.  (2004).  ASHRAE  STANDARD  Thermal  Environmental  Conditions  for  Human  Occupancy.  Ashrae Standard, 2004.[20] Erdmann, C. A., Steiner, K. C., & Apte, M. G. (2002). INDOOR CARBON DIOXIDE CONCENTRATIONS AND SICK BUILDING SYNDROME SYMPTOMS IN THE BASE STUDY REVISITED : ANALYSES OF THE 100 BUILDING DATASET. Indoor Air, 443-448.IX- Appendices The appendix files are located in a digital folder accompanying the digital version of this report.  Some of the appendices are absolutely necessary to understand the results and the whole analysis.  The other files  are  supporting documents  for  additional  insight  on the system or complementary understanding. A list of the files available is posted in this section of the report. Please contact SEEDS office to request the files. • Appendix_1_Flow_Meter_User_Manual_ABB ACG550 PCR.pdf• Appendix_2_ VOC_Sensor_Greystone Air 300.pdf• Appendix_3_ Honeywell_Temperaturre_C70xx sensors.pdf• Appendix_4_ Honeywell_CO2_sensor_C7632.pdf• Appendix_5_ Honeywell Humidity H763x.pdf• Appendix_6_ Honeywell Press P7640.pdf• Appendix_7_ UltraTech Air Flow Stations EDPTjr OM.pdf• Appendix_8_ AHU_Specifications.pdf• Appendix_10- Honeywell TR21_TR24 temp sensor.pdf• Appendix_12- AHU2_Sequence_of_Operation.pdf• Appendix_13_Image_Auditorium.jpg• Appendix_14_Image_Auditorium.jpg• Appendix_15_Image_Auditorium.jpg• Appendix_16_Image_Auditorium.jpg• Appendix_17_Image_Auditorium.jpg• Appendix_18_Image_Auditorium.jpg• Appendix_19_Image_Auditorium.jpg• Appendix_20_Image_Auditorium.jpg• Appendix_21_Image_Auditorium.jpg• Appendix_22_Image_Auditorium.jpg• Appendix_23_Image_Auditorium.jpg• Appendix_24_ A-101 - Floor Plan Level Ground.pdf• Appendix_25  Understanding How to Calculate Enthalpy of Moist Air.pdf• Appendix_26_Experiment_1_Test_Period_1_9am_to_4pm_Results.pdf Page 73/74• Appendix_27_Experiment_1_Test_Period_1_All_Day_Results.pdf• Appendix_28_Experiment_2_Test_Period_1_9am_to_4pm_Results.pdf• Appendix_29_Experiment_2_Test_Period_1_All_Day_Results.pdf• Appendix_30_Experiment_3_Test_Period_1_9am_to_4pm_Results.pdf• Appendix_31_Experiment_3_Test_Period_1_All_Day_Results.pdf• Appendix_32_Experiment_4_Test_Period_1_9am_to_4pm_Results.pdf• Appendix_33_Experiment_4_Test_Period_1_All_Day_Results.pdf• Appendix_34_Experiment_5_Test_Period_1_9am_to_4pm_Results.pdf• Appendix_35_Experiment_5_Test_Period_1_All_Day_Results.pdf• Appendix_36_Experiment_6_Test_Period_1_9am_to_4pm_Results.pdf• Appendix_37_Experiment_6_Test_Period_1_All_Day_Results.pdf• Appendix_38_Experiment_7_Test_Period_1_9am_to_4pm_Results.pdf• Appendix_39_Experiment_7_Test_Period_1_All_Day_Results.pdf• Appendix_40_Experiments_Comparison_Absolute_Trial_1.pdf• Appendix_41_Experiments_Comparison_Relative_Trial_1.pdf• Appendix_42_Experiment_1_Test_Period_2_Results_9am_to_4pm.pdf• Appendix_43_Experiment_1_Test_Period_2_Results_All_Day.pdf• Appendix_44_Experiment_2_Test_Period_2_Results_9am_to_4pm.pdf• Appendix_45_Experiment_2_Test_Period_2_Results_All_Day.pdf• Appendix_46_Experiment_3_Test_Period_2_Results_9am_to_4pm.pdf• Appendix_47_Experiment_3_Test_Period_2_Results_All_Day.pdf• Appendix_48_Experiment_4_Test_Period_2_Results_9am_to_4pm.pdf• Appendix_49_Experiment_4_Test_Period_2_Results_All_Day.pdf• Appendix_50_Experiment_5_Test_Period_2_Results_9am_to_4pm.pdf• Appendix_51_Experiment_5_Test_Period_2_Results_All_Day.pdf• Appendix_52_Experiment_6_Test_Period_2_Results_9am_to_4pm.pdf• Appendix_53_Experiment_6_Test_Period_2_Results_All_Day.pdf• Appendix_54_Experiment_7_Test_Period_2_Results_9am_to_4pm.pdf• Appendix_55_Experiment_7_Test_Period_2_Results_All_Day.pdf• Appendix_56_Experiments_Comparison_Absolute_Trial_2.pdf• Appendix_57_Experiments_Comparison_Relative_Trial_2.pdfAppendix_58_Automatic_Day_1_Results_9am_to_4pm.pdf• Appendix_59_Automatic_Day_1_Results_All_Day.pdf• Appendix_60_Automatic_Day_2_Results_9am_to_4pm.pdf• Appendix_61_Automatic_Day_2_Results_All_Day.pdf• Appendix_62_Automatic_Day_3_Results_9am_to_4pm.pdf• Appendix_63_Automatic_Day_3_Results_All_Day.pdf• Appendix_64_Automatic_Day_4_Results_9am_to_4pm.pdf• Appendix_65_Automatic_Day_4_Results_All_Day.pdf• Appendix_66_Automatic_Day_5_Results_9am_to_4pm.pdf• Appendix_67_Automatic_Day_5_Results_All_Day.pdf• Appendix_68_Auto_Day_Results_2_Comparison.pdf Page 74/74

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