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Drain water heat recovery : a review of performance, economics, practical issues and applications Frankowski, Chris 2013-05-06

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UBC Social Ecological Economic Development Studies (SEEDS) Student Report       Drain Water Heat Recovery  Chris Frankowski  University of British Columbia CEEN 596 May 6, 2013           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”.         Drain Water Heat Recovery A review of performance, economics, practical issues and applications          CEEN 596 Final Project  May  6 , 201 3   Chris Frankowski  1   Executive Summary This project evaluates the economics of Drain Water Heat Recovery ( DWHR ),  more specifically the performance of a horizontal DWHR device manufactured by EcoDrain, the A1000 . The device was tested in a rig that mimics a typical real world installation. The temperature increase and flow rate of fresh water passing through the devi ce was recorded  to determine the energy saved while showering . Both the transient and steady state pe rformance of the device  was  determined. By combining the testing results with a dataset of Canadian household sizes, showering habits, and energy costs, a recommendation is made for the conditions under which the installation of an EcoDrain would be economically advantageous.  The testing simulates an installation where the fresh water being preheated supplies only the associated fixture , which would be the e asiest installation for an existing building. Testing showed an average temperature increase of 12.2 °C with a flow rate of 3.87 L/min of fresh water passing through the DWHR device, which corresponds  to a heat transfer rate (power  savings) of 3.29 kW , and a total of 0.43 kWh saved per shower .  The average Canadian household has a size of 2.59 people, with each person shower ing once a day for 8.5 minutes each. Energy costs vary significantly around the country, but the average electricity rate is 9.41¢/kWh an d 7.13 $/GJ. For the average household, the NPV of DWHR is - $203 .68 for homes with electric water heaters and - $464 .88  for homes with natural gas water heaters.  DWHR is much more economic al for households with electric hot water heaters as their energy cos ts are much higher. A household of 4 or more people with an electric hot water heater would benefit from installing a DWHR device such as the EcoDrain. Locations with natural gas heaters would benefit from DWHR if there are more than 14 users a day, or if natural gas prices return to more historic levels.   2   Acknowledgements I  would like to thank Dr. Eric Mazzi  for finding this project opportunity and continuous help along the way , and also for all the work he does for the CEEN program and its students . I wou ld also like to thank David Velan, who manages EcoDrain. David provided the EcoDrain A1000 for testing, as well as support in securing an installation location and technical support regarding installation, testing, and general information.  I would also lik e to thank  Brenda Sawada,  Lillian  Zaremba, Jeff  Giffin ,  and everyone at UBC Campus +  Community planning for their time and efforts in finding a location on campus to install the EcoDrain.  Although we weren’t able to secure a location for installation due to time constraints, the experience was valuable and hopefully we’ve laid some groundwork for a future student. Finally, I would like to thank those closest to me. M y parents , who have  shown me how much is possible with hard work  and have inspired me to fol low my dreams no matter how challenging that journey may be . Babcia,  for your continuous support and endless kindness throughout my life .  Dianne, you’ve brought  us to where we are today, thank you.    3   Table of Contents Executive Summary  ...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  1  Acknowledgements  ...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  2  Introduction  ...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  4  Background  ...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  4  Installation at UBC  ...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  8  Purpose and Objectives  ...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  9  Motivation  ...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  10  Literature Review  ...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  11  Data Sources and Methodology  ...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  12  Statement of Typical Conditions  ...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  14  DWHR Performance Eval uation ...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  16  Testing Setup  ...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  16  Testing Methodology  ...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  18  Results and Discussion ...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  19  Testing Results  ...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  19  Steady State Performance  ...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  19  Transient Response  ...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  21  Installation and Maintenance Costs  ...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  23  NPV  ..... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  24  Sensitivity Analysis  ...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  25  Break - Even ...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  26  Scenarios ...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  27  High Use  ...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  27  Atlantic Canada  ...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  28  Improvements  ...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  29  Use for DMS and Implications  ...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  30  Other Considerations  ...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  31  Conclusions ...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  32  Significance of Work  ..... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  32  Recommendations ...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  33  W orks Cited  ...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  34  Appendix A – Calculations ...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  37  Appendix B – NRCAN DWHR testing procedure  ...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  38  Appendix C – EcoDrain A100 0 DataSheet  ...... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  39   4   Introduction Background Drain water heat recover (DWHR) is the process of transferring heat from an effluent flow  to another flow  that requires heating , thereby utilizing energy  that would have otherwise been wasted.  A DWHR device is a heat exchanger that allo ws this heat transfer to occur, while ensuring that the two flows do not mix. Th is project analyzes the use of a DWHR device in a r esidential setting wh ere the effluent stream is grey water from a bathroom shower that is used to heat fresh water.  A DWHR device must be designed to withstand  an effluent stream with irregular flow containing a mixture of  various liquids and solids,  with little to no maintenance. This durability comes as a sacrifice of performance and size.  A ll of the  DWHR device s currently eligible for Natural Resources Canada ’s incentives (ThermoDrain, Power - Pipe, and Watercycle ) consist of  a similar design including copper tubing wrapped around a copper drain pipe that is to be installed in a vertical portion of drain piping . This project reviews the performance of the A1000 DWHR device made by EcoDrain,  which is a horizontal DWHR device.  Horizontal DWHR devices have seve ral advantages over vertical DWHR devices  including more flexible installation options and opportunities for innovation and cost reductions. Installation op tions for a vertical DWHR device are limited to perfectly vertical pipe .  If the pipe is not perfectl y vertical, the tested heat transfer rate will not be achieved  because the water will not completely and evenly cling to the inside wall of the pipe as is necessary . Horizontal DWHR devices can be installed on horizontal or slo ped runs, which occur more fr equently  (installation is feasible in more locations) , are closer to the fixture  (higher efficiencies due to l ower  heat loss , and lower likelihood of having cold effluent streams running through the DWHR device), and are more accessible generally  (construction will have a smaller and more contained footprint) .   5   T he design of vertical DWHR devices has changed very little over the time that they’ve been available , and it is unlikely that the design can be significantly improved or for drastic cost savings to be achieved. The horizontal DWHR device from EcoDrain has more components  but  contains less copper. The  modular design has more opportunities for design improvements and variety ,  for example varying performance for a variety of acceptable pressure drops.  By having a smaller portion of the price attributed to material costs there are greater opportuni ties for cost savings through larger scale production and the cost will be less affected  by  rising copper prices.   A DWHR device can be plumbed  in multiple conf igurations depending on the location of the DWHR device relative to the water heater and the fixture. The choice of configuration will affect installation costs as well as the energy savings achieved.  The three most common configurations are shown on the f ollowing page  in Figure 1 .  Configuration A has the fresh water exiting the DWHR device running directly to the shower fixture .  Configuration B has the fresh water exiting the DWHR device running directly to the water heater.  The l ast option, configuration C, is a combination of the two other configurations. Fresh water is piped through the DWHR and then splits to both the fixture as well as the water heater. Configuration A is the easiest to install in an existing building as plumb ing modifications will only need to occur close to the fixture. Configuration C is the most efficient as it has the largest fresh water flow through the DWHR device , matching the volume of water flowing through the drain side . The temperature gain will be the lowest, but it is applied to a large volume of water.  Both options B and C require running the main cold water line through the DWHR device and back to the water heater , which in most cases will be separate d by a large distance, and in existing homes w ould require a large amount of construction . Since this project will be considering retrofitting DWHR devices into existing homes, configuration A will be used to determine savings.    6   Configuration A Configuration B Configuration C Figure 1: Installation configurations for DWHR devices The DWHR device that is being studied in this project is the EcoDrain A1000 . It is shown on the next page  in Figure 2 . The device has a heat exchanger length of 1 22 cm (48’’) ,  a total length of 1 42  cm (56’’) , a width of 13 cm (5’’), and a height of 11 cm (4.5’’) .  The body of the device is made of plastic.  The device consists of the upper drain water region where the effluent steam flows, having a flat copper bottom.  A p hotograph of the interior of the device is shown  on a following page  in Figure 3 .  The lower region of the device is for the fr esh water flow, and contains a turbulator  to increase the heat transfer coefficient of the fresh water p assing through it. Most building and plumbing codes  require a double 7   wall construction to ensure that grey water does not cross over into the fresh supply water. The A1000 has a double wall design and  also features a vent connected to the  interface between  the double wall,  which provides an indication if either of the walls of the heat exchanger begin to leak.  More information , including dimensions, connection options, and installation schematics are  available in A ppendix C, the datasheet for the EcoDrain A 1000 .    Figure 2: The EcoDrain A1000  8    Figure 3: The interior of the EcoDrain A1000  Installation at UBC The initial scope of this project included the installation of the EcoDrain in an actual shower on UBC campus. A suitable location would have a shower with heavy use that also had easy access to the DWHR device while installed for testing purposes. Multiple locations were scouted over a three week period including the Student Recreation Centre, War Memo rial Gymnasium, UBC Aquatics Centre, and the Chemical  & Biological Engineering Building . The UBC Aquatic Centre was the best candidate because of the high frequency of shower use and access below the showers, but an installation was unable to be organized within the time constraints. The remainder of the buildings have their showers located on the 9   lowest level with drainage piping in the floor, which would have made testing difficult and installation costs prohibitively high, making them unviable candidates .  Another concern with installing the DWHR device on campus was receiving approval of the UBC plumbing inspector. The feedback that was given to a demo installation focused on health and safety concerns regarding cross connection. Approval was given for a  trial installation on the condition that a reduced backflow device was required for potable water connections and that the leak vent indicator needed to be plumbed to a high visibility drain. Certification of the device was a requirement for larger scale deployment. At the time of this writing, the EcoDrain is in the process of being listed for the Uniform Plumbing Code (UPC) by the International Association of Plumbing and Mechanical Officials (IAPMO) in California, and the Canadian UPC (cUPC) by the Cana dian Advisory Council on Plumbing (CACP).  Purpose and Objectives The purpose of this project  is to evaluate the performance of a DWHR system in a real world setting in order to assess the economics and practicality of using DWHR systems to reduce energy co nsumption. A commercially available unit, the EcoDrain A1000 , will be installed in a rig that mimics typical showering plumbing and piping  and the performance characteristics of the unit will be measured. This information will form the basis of an economic  assessment, including the net present value, of installing a DWHR system under different conditions.  The key variables in the economic assessment of this system will be the capital and installation costs of the device, the volume of drain water that flows  through the system (which is the prod uct of the flow rate of the showerhead and the total length of showers taken), and the cost of heating water ( energy  costs and heater efficiencies). The testing will find the conditions necessary for a DWHR system to b e economically viable and will produce a calculator tool that finds the net present value given an 1 0   estimated operating environment.  A recommendation will be made with suitable applications for DWHR systems and a consideration of employing incentives to inc rease DWHR system installations as a form of demand side management (DSM).  Motivation Heating water is the second biggest household energy use (after space heating) in Canada, accounting for 17% of residential energy use in 2010 [1] . Canadians use approximately 347 PJ of energy to heat water for residential and commercial use, and emit 18 megatons of CO 2  equivalent greenhouse gases to do so [2] . Other research finds that 25% to 41% of this hot water use can be attributed to showering [3], [4] . Finally, 80 - 9 0% of the energy added in a water heater is still contained in the water going down the drain of a shower [5] . These facts represent a massive opportun ity for energy use and greenhouse gas emissions reductions which can be realized by transferring energy from the hot drain water to cold incoming fresh water using a heat exchanger.  It is my personal belief that the carbon and energy crises will be the gre atest challenges faced  by humanity .  Our societ ies ha ve developed in the presence of cheap and abundant energy , and have created infrastructure and lifestyles that rely on it .  With the fast approaching end of conventional fossil fuels and the need to drasti cally reduce carbon emissions, we must change the existing infrastructure and lifestyles to work in a low carbon  and low energy world.  Effective DSM is critical to making this transition.     1 1   Literature Review There is a lack of significant research in the field of DWHR systems, and the studies that have been completed are based on laboratory testing or computer simulation. The research is focused primarily on efficiencies of differen t designs and does not address the practical and economic implications of installing such a system.   A report titled “Drain Water Heat Recovery Characterization and Modeling ” compared eight different models (2 from 4 different manufacturers) of DWHR systems in terms of the Number of Thermal Units (NTU) and effectiveness  and found  that NTU per wrapped foot ranged from 0.17 to 0.33 and that effectiveness ranged from 0.1 to 0.16 per foot of wrapped length between the different models [6] . The report focused on theoretical efficiencies and did not do a broad economic evaluation of DWHR systems.   A 2011 ASHRAE journal article covers DWHR systems in the Emerging Tech nologies section, and mentions efficiencies of up to 40% with payback ranging from 2 - 5 years [5] .  Research from the Hong Kong Polytechnic Universit y titled “Shower water heat recovery in high - rise residential buildings of Hong Kong ” showed that only 4 - 15 % of shower water heat can be recovered using a 1.5m long single - pass counter– flow heat exchanger on a 50 mm drainage pipe. [7] . The experiment was performed using a lab setup and a custom DWHR unit with thermocouples at all inlets and outlets and flow meters on both flows.   Another prototype built for testing purposes generated annual savings of $160 , but w as based on a standard heat exchanger and not a commercial product specifically for DWHR [8] . A valid economic assessment could not be made as real world costs were not included, and performance data could have been potentially skewed due to the ideal conditions that the unit was operated under (not used in an actual shower). No assessment of maintenance issues was made in any of the studies.  1 2   Natural Resources Canada (NRCan) has a protocol establish ed to standardize testing procedures  for DWHR ,  but it is limited to vertical DWHR devices  (Appendix B) . The testing procedu re stipulates even flow conditions (drain water flow rate matches fresh water flow rate, configuration C described earlier). The protocol employs a n energy balance to ensure accuracy (the heat gained by fresh water must match the heat loss on of the drain water within 5% for the results to be valid).  The performance is based on the steady state heat transfer, and the pressure drop of fresh water across the DWHR device is measured.  Data Sources and Methodology The economic analysis of DWHR units that is per formed is the product of two sets of data. The first set of data describe s the  conditions that a DWHR device will be exposed to in an  average Canadian home. This includes  water heater type and efficiency (electric / natural gas), energy  costs, showering wa ter temperatures, shower  head  flow rates, and the frequency and duration of showers. The second data set is derived from the testing performed as part of this project. A test rig will be constructed that mimics the plumbing associated with showers  and the DWHR unit will be exposed to the conditions described in the first data set. By combining these two data sets, the economics of installing a DWHR will be determined.  T he effectiveness of the system will be quantified by measuring the amount of energy added  to the cold water supply. This can be calculated by recording the inlet and outlet temperatures and flow rate of fresh water through the DWHR system.    1 3   The temperature transfer efficiency can be calculated using the formula:  µ𝑡 =  (𝑡2 − 𝑡1)(𝑡3 − 𝑡1) Where: µ𝑡 is the temperature transfer efficiency, and 𝑡1 , 𝑡2 , and 𝑡3 are the temperatures of the incoming fresh water, incoming drain water, and outgoing freshwater, respectively.  The equipment used to measure temperature and f low rates during testing is presented below in Table 1 . The temperature measurement has an accuracy of ± 0.1°C.  Device Description Drain Water Heat Recovery Unit  EcoDrain A1000  Temperature Sensors  Omega Thermistors, TH - 10 - 4 40 34 - 1/ 8 - 4 - 40  Temperature Logger  Omega Logger, OM - USB- TEMP  IR Temperature Sensor  SKF TMTL 260 ThermoLaser  Portable Water Meter  Endress&Hauser Prosonic Flow 93P  Table 1: Equipment used to measure DWHR system performance    1 4   Statement of Typical Conditions In order for an accurate assessment to be made on the impact of installing a DWHR device in a Canadian home, a summary of typical hot water systems, energy costs, and showering habits must be made.  Electricity and natural gas prices v ary province to province, and even city to cit y, and include various connection, demand, time of use, and delivery charges. For this analysis, savings will only be considered for consumption charges, and a simplified summary of those costs are presented by  province in Table 2  and Table 3  below.  P rovince City Provider Comment Rate (¢/kWh) Rate ($/GJ) BC Vancouver  BC Hydro  Step 2  10.34 [9]  28.72  AB  Calgary  Enmax  5 year fixed rate  8.90 [1 0 ]  24.72  SK  Saskatoon  Saskatoon Light and Power   12.24 [11 ]  34.00  MB  Winnipeg  Manitoba Hydro   6.94 [1 2 ]  19.28  ON  Toronto  Toronto Hydro  Mid - peak Price  9.90 [1 3 ]  27.50  QC  Montreal  Hydro Quebec  Above 30kwh/day  7.78 [1 4 ]  21.61  NB  Saint John  Saint John Energy   9.05 [1 5 ]  25.14  NS  Halifax  Nova Scotia Power   13.79 [16 ]  38.31  PE  Charlottetown  Maritime Electric   12.41 [17 ]  34.47  NL  St. John's  Newfoundland Power   11.17 [18 ]  31.03  Table 2: Provincial electricity costs  Province City Provider Comment Rate ($/GJ) BC Vancouver  Fortis BC   7.86 [1 9 ]  AB  Calgary  Enmax  5 year fixed  5.99 [1 0 ]  SK  Saskatoon  SaskEnergy   5.71 [2 0 ]  MB  Winnipeg  Manitoba Hydro  Primary Gas  6.12 [2 1 ]  ON  Toronto  Enbridge Gas  "Next 55"  6.37 [2 2 ]  QC  Montreal  Gaz Metro  Rate D 6.41 [2 3 ]  NB  Saint John  Enbridge Gas New Brunswick   17.29 [24 ]  NS  Halifax  Herit age Gas   18.15 [25 ]  PE  Charlottetown   Not available in PE  N/A  NL  St. John's   Not available in NL  N/A  Table 3: Provincial natural gas costs  1 5   As is shown in Table 2 , the rate for the equivalent amount of energy in electricity is much higher than it is for natural gas. This is caused by the inefficiencies of the conversion of thermal energy to electric energy. The National average ener gy cost for electricity and natural gas were calculated by performing a weighted average of provincial costs by provincial population. The weighted average cost s w ere found to be 9.41 ¢/kWh  for electricity  and 7.13 $/GJ  for natural gas .  Hot water boilers f uelled by electricity and natural gas are both very common. The proportion of each by province is shown below in Table 4 , along with populations and household sizes . Electric hot water heaters use immersed resistance coils and transfer nearly all of the electric energy to the water. Efficien cies of natural gas boilers vary significantly depending on design and age ,  from 60 % to 95 %. For the economic analysis performed in this project, a boiler efficiency of 80% is used.   Population Households People/Household % Electric HWH % Natural Gas HWH  Canada 34,484 ,000  13,3 20 ,610  2.59  41.2  48.2  B.C.  4,57 6 ,6 00  1,76 4 ,6 35  2.59  33  58.7  Alta.  3,77 8 ,1 00  1,39 0 ,2 75  2.72  5.2  84.2  Sask.  1,05 7 ,8 00  409 ,64 5  2.58  30.7  63  Man.  1,25 1 ,7 00  466 ,14 0  2.69  30 .7  63  Ont.  13,3 66 ,300  4,88 7 ,5 10  2.73  22.1  67.9  Que.  7,97 8 ,0 00  3,39 5 ,3 40  2.35  89.1  2.7  N.B.  755,30 0  314 ,01 0  2.41  72.6  *  N.S.  948,50 0  390 ,28 0  2.43  72.6  *  P.E.I.  145 ,70 0  56,4 60  2.58  72.6  0  N.L.  512 ,90 0  208 ,84 5  2.46  72.6  0  Table 4: Canadian population, households, and HWH mix from Statistics Canada [26]  and NRCan[ 27]   The duration of an average shower is difficult to determine, but based on re search of showering and water use,  the average shower was found to be 8.5 minutes  long [28]  with  a frequency of approximately once a day . The temperature of a shower will also vary by user preference . To keep things consistent, the temperature of 36°C from the NRCan DWHR testing protocol is used in this testing.  1 6   The lifetime of the DWHR device was ev aluated at 15 years based on the  “Measure of Life” study for energy evaluation  performed for the state of Wisconsin [29] .  DWHR Performance Evaluation Testing Setup A test rig was constructed in order to replicate the conditions that would be experienced by a DWHR unit installed in an actual shower. More specifically, the system wa s in configurati on A, as described earlier, where the cold water supplying the shower mixing valve passes through the DWHR un it where it recovers heat from the drain water.  A schematic of the layout and instrumentation is shown on the following page in Figure 4  In order to measure the heat gained by the fresh water  in the DWHR device, the temperature wa s measured at the inlet and outlet. Immersion thermistors were  used, which offer ±0.1 °C accuracy .  The flow rate was measured at the inlet to the DW HR device using a clamp- on ultrasonic f low meter.  The temperature of the hot water supply was periodically checked using an infrared temperature sensor to ensure that it remained at 45 °C.  Following the mixing valve, the water was poured into a basin that s lopes slightly towards a drain, as would be present in an actual shower. The temperature and flow rate are measured to ensure conf ormance with Canadian averages, 3 6 °C and 9.5 L/min.  The drain plumbing replicates that of building code standards, including a  p- trap. The drain connects to the EcoDrain which is sloped at 3/8‘’ per foot (1.79°) . The line then releases into an open building drain .  A photograph of the actual testing rig is shown in Figure 5 .  1 7    Figure 4: Schematic of testing setup   Figure 5: The testing setup  1 8   Testing Methodology The system was kept in a room temperature (2 0 °C) environment for 30 minutes before each trial in order to incorporate the effects of warming up t he parts of the system. Including these transient effects more accurately represent an actual shower system where showers are short and/or infrequent.  Before running the shower water through the system, the temperate and flow rate were set to their target values. The temperat ure was measure d via a thermistor  probe inserted into the flow. The flow rate was measured by timing the filling of a container of known volume, in this case a bottle  that was 2 L. Adjustments were made until both values reached their t arget. Both measurements were then repeated to confirm they were at their target. Next, the logging was started on the flow meter and the temperature probes.  Finally, the shower flow was put into the shower drain system. With the shower water running thro ugh the drainage piping and DWHR device, the system warmed up. As the DWHR system warmed up, it transferred energy to the cold water supply, increasing its temperature which would have raised the temperature of the shower water. The mixing valve was adjust ed to increase the cold water flow rate to maintain the temperature in the shower, and the hot water flow rate was decreased to maintain the flow rate at 9.5 L/min.  The system was ru n until a steady state was reached and maintained for 5 minutes.  The wate r flow was turned off and the system was left for 30 minutes to allow the component s to return to room temperature before performing additional trails.  The data processing and analysis are described in the results section below.  The test was repeated 3 tim es to ensure accuracy by verifying the consistency of the results. The average energy transfer of the 3 tests was used in the following economic analysis.   1 9   Results and Discussion Testing Results The following results are for the performance of the EcoDrain  A1000 running in configuration A described earlier . The shower water temperature was set at 36°C with a flow rate of 9.5 L/min. The device was installed at a slope of 3/8‘’ per foot (1.79°). According to EcoDrain Performance can be improved by 5 - 10 % by in stalling the device at a larger slope, up to 75° [30 ] .   Steady State Performance The steady state conditions for the three runs  are shown in Figure 6  on the following page and are summarized below in  Table 5 . The average steady state values will be used in all further analysis.    Run 1 Run 2 Run 3 Average Temp In (°C) 1 1 .1  11.3  10.9  11.1  Temp Out (°C) 2 3 .3  23.1  23.5  23.3  Drain (°C) 3 6 .2  35.8  36.0  36.0  Flow (L/min) 3 .83  3.94  3.83  3.87  Table 5: Summary of steady state characteristics  Based on the values in Table 5  above, the steady state heat transfer rate is 3284 W (calculation shown in appendix A) . For the  average 8.5 minute shower , the DWHR device would save 0.465  kWh of water thermal energy .    2 0     Figure 6: The steady state conditions of the 3 runs   05101520253035400 10 20 30 40 50Time (s)Run 1 Steady State05101520253035400 10 20 30 40 50Time (s)Run 2 Steady State05101520253035400 10 20 30 40 50Time (s)Run 3 Steady State2 1   Transient Response The transient response of the three runs is shown in Figure 7  on the following page  and in Table 6  below . There is a delay of approximately 10 seconds  after  beginning the shower bef ore there is an increase in the temperature of the fresh water exiting the DWHR unit. A further 60 seconds are required before the temperature of the water exiting the DWHR device  reaches the steady state  value.  During th ose 72 seconds,  the DWHR device tra nsfers 46.4% of the energy it would have if it were operating a steady state levels.     Run 1 Run 2 Run 3 Average Warm Up Time (min) 1 :1 6  1:1 0  1:0 9  1:1 2  Average Heat Transfer (kW) 1 .55  1.57  1.44  1.52  SS Heat Transfer (kW) 3 .23  3.23  3.38  3.28  Transient % of SS 4 8 .0%  48.6%  42.5%  46.4%  Table 6: Summary of transient response characteristics    2 2      Figure 7: The transient response of the 3 runs 10121416182022240 10 20 30 40 50 60 70 80 90Time (s)Run 1 Transient Response10121416182022240 10 20 30 40 50 60 70 80 90Time (s)Run 2 Transient Response10121416182022240 10 20 30 40 50 60 70 80 90Time (s)Run 3 Transient Response2 3   Installation and Maintenance Costs The economic analysis assumes that the installation of the DWHR device occurs during a major renovation of a bathroom. Under these circumstances, the marginal cost of installing the DWHR device will be negligi ble compared to the remainder of the renovations being done. If an extremely conservative approach is to be taken, then an installation cost of $200 can be applied, which will decrease the NPVs presented in the following sections by $200 .  The grey water si de of the EcoDrain was designed to not add any additional restrictions to the effluent flow compared to a 2’’ drain pipe. As a result, the maintenance cost of a shower with a DWHR device will not be any different from a shower without one . If a shower clog ged frequently before the installation of a DWHR device, it will continue to clog frequently. If a shower did not normally clog, the addition of a DWHR device should not increase the likelihood of clogs. Once again, taking  an extremely conservative approach, we can add an hour of maintenance every 3 years to correspond to a cleaning of the drainage piping and DWHR device, which would decrease the NPVs in the following sections by $26 7 .7 6    2 4   NPV The net p resent value of installing the EcoDrain A1000 was calculated based on the values in Table 7  below.  The results by provin ce are presented in Table 8  below.  Example calculations are in Appendix A.  Values differ by province due to varying energy costs  and household sizes . Note that natural gas is not available in PEI and Newfoundland and Labrador.   Base case Discount rate 5 %  Cost ($) 6 00  Steady state heat transfer (kW) 3 .28  Shower Length (minutes) 8 .5  Electricity rate (¢/kWh)  9 .41  Natural Gas rate ($/GJ) 7 .13  Lifetime (years) 1 5  Table 7: NPV parameters    Annual Savings ($) NPV ($) Payback (years)   Electric Natural Gas Eletric  Natural Gas Electric  Natural Gas Canada 38.18  13.02  - 203 . 6 8  - 464 .88  15.71  46.09  B.C.  42.04  14.38  - 163 .63  - 450 .73  14.27  41.72  Alta.  37.92  11.48  - 206 .44  - 480 .81  15.82  52.25  Sask.  49.55  10.40  - 85 .69  - 492 .03  12.11  57.68  Man.  29.21  11.59  - 296 .76  - 479 .66  20.54  51.75  Ont.  42.44  12.29  - 159 .44  - 472 .48  14.14  48.84  Q ue.  28.66  10.63  - 302 .54  - 489 .71  20.94  56.47  N.B.  34.13  29.34  - 245 .78  - 295 .43  17.58  20.45  N.S.  52.54  31.12  - 54 .66  - 276 .99  11.42  19.28  P.E.I.  50.21    - 78.88   11.95   N.L.  43.01    - 153 .58    13.95    Table 8: NPV and payback results The NPV of installing a DWHR device is not positive for the average Canadian household. The NPV is highest for homes with electric water heaters and high energy costs (Saskatchewan, Nova Scotia, and PEI)    2 5   Sensitivity Analysis Here a sensitivity analysis is performed to determine the variables that have the most significant impact on the NPV of a DWHR system. Each variable from the base case NPV  calculation is modified one at a time to a value 20% higher and 20% lower than the base case , as shown in Table 9  below . The NPV and % change  from base case  are calculated and shown below in Table 10  and Table 11   -20% Base case +20% Discount rate 4 %  5%  6%  Cost ($) 4 80  600  720  Steady state heat transfer (kW) 2 .62  3.28  3.94  Number of users 2 .07  2.59  3.11  Electric rate (¢/kWh) 7 .53  9.41  11.29  Natural Gas rate ($/GJ) 5 .70  7.13  8.56  Lifetime (years) 1 2  15  18  Table 9: Variable values for sensitivity analysis F or systems with electric  water heaters ,  the NPV is most sensitive to the capital costs. Since a relatively low discount rate was selected, the 20% increase or decrease does not have a significant impact on the NPV. Since the steady state heat transfer, number of users, and energy rates are all linearly related to the annual savings, the % change is the same for those 3 variables.      NPV   % Change -20% Base Case +20% -20% 20% Discount rate - 1 75 .39  - 203 .61  - 229 .09   14%  - 13 %  Cost ($) - 8 3 .61  - 203 .61  - 323 .61   59%  - 59 %  Steady state heat transfer (kW) - 2 82 .88  - 203 .61  - 124 .33   - 39 %  39%  Number of users - 2 82 .88  - 203 .61  - 124 .33   - 39 %  39%  Electric rate (¢/kWh) - 2 82 .88  - 203 .61  - 124 .33   - 39 %  39%  Natural Gas rate ($/GJ)       Lifetime (years) - 2 61 .52  - 203 .61  - 153 .58   - 28 %  25%  Table 10: NPV response to sensitivity analysis for electric HWH 2 6   The lower energy costs of natural gas water heaters decrease the significance of the variables that contribute to ann ual savings, further emphasiz ing the importance of capital cost in the final NPV value of a DWHR unit.     NPV   % Change -20% Base Case +20% -20% 20% Discount rate - 4 84 .18  - 491 .87  - 498 .83   2%  - 1%  Cost ($) - 3 71 .87  - 491 .87  - 611 .87   24%  - 24 %  Steady state heat transfer (kW) - 5 13 .50  - 491 .87  - 470 .25   - 4%  4%  Number of users - 5 13 .50  - 491 .87  - 470 .25   - 4%  4%  Electric rate (¢/kWh)       Natural Gas rate ($/GJ) - 5 13 .50  - 491 .87  - 470 . 2 5   - 4%  4%  Lifetime (years) - 5 07 .67  - 491 .87  - 478 .23   - 3%  3%  Table 11: NPV response to sensitivity analysis for natural gas HWH  Break-Even  The break even analysis below is performed for each variable of the NPV calculation. The variable is adjusted while keeping the other variables as base case until an NPV of 0 is reached , i f possible. The results of the analysis are shown below in  Table 12 . The analysis shows that energy rates above 14.24 ¢/ kWh  for electricity and 39.56 $/GJ for natural gas create a positive NPV under the conditions of an average hou sehold.  Households with electric hot water heaters hav ing 4 or more people would also be viable candidates for having DWHR installed.  The breakeven for cost shows that a price of less than $ 400 would create a positive NPV for the average household with an electric heater, but a much lower cost is required for homes with natural gas water heaters.  It is not possible to achieve a positive NPV by varying discount rate alone.    27     Electric HWH  Natural Gas HWH    NPV ($)   NPV ($) Discount rate 0% -27.16  0% -443.74 Cost ($) 396.39 0.00  108.13 0.00 Steady state heat transfer (kW) 4.96 0.00  18.20 0.00 Number of users 3.92 0.00  14.37 0.00 Electric rate (¢/kWh) 14.24 0.00    Natural Gas rate ($/GJ)    39.56 0.00 Lifetime (years) 31.56 0.00  1167 -391.66 Table 12: Break-even analysis for electric and natural gas HWH  Scenarios Although the NPV calculation for provincial averages was negative, there are many cases where installing a DWHR would provide a positive NPV. Below are 3 examples of cases where DWHR would provide economic benefit. High Use This scenario describes an installation in a location where the DWHR device would receive much higher usage then average, for example in a dormitory with common showers, or in recreational facility showers. The number of users was increased to 48 (6 an hour for 8 hours). Maintaining all other variables at base case settings, the total savings would be $1,800 for locations with natural gas water heaters, and over $8,000 for locations with electric water heaters. Results are shown in Table 13 on the following page.   28        NPV      Natural Gas Electric Discount rate 5%  $1,807 $8,224 Cost ($) 600    Steady state heat transfer (kW) 3.28      Number of users (people) 48    Electric rate (¢/kWh) 9.41      NG rate ($/GJ) 7.13    Lifetime (years) 20      Table 13: NPV for high use scenario  Atlantic Canada This scenario describes a household of 4 or more people in Atlantic Canada. According to Statistics Canada, there are more than 3 million households in Canada with 4 or more people[26]. The combination of above average usage and higher electrical (natural gas not available in parts of Atlantic Canada) costs result in a positive NPV, as shown in Table 14 below.      NPV      Electric   Discount rate 5%  $337   Cost ($) 600    Steady state heat transfer (kW) 3.28      Number of users (people) 4    Electric rate (¢/kWh) 14.4      Natural Gas rate ($/GJ)     Lifetime (years) 15      Table 14: NPV for Atlantic Canada scenario   2 9   Improvements This scenario is based on further improvements to the EcoDrain A1000 design  and performance , cost reductions through mass production, and installation at a higher angle for a higher heat transfer rate.  With a 30% increase in performance and a 30% de crease in price, the DWHR device would be economically beneficial for the average household with an electric hot water heater. The results are shown  in Table 15 .        NPV      Natural Gas Electric Discount rate 5 %   - $28 4 .26  $77 .64  Cost ($) 4 20     Steady state heat transfer (kW) 4 .264       Number of users (people) 2 .5     Electric rate (¢/kWh) 9 .41       Natural Gas rate ($/GJ) 7 .13     Lifetime (years) 1 5       Table 15: NPV for improvements scenario    3 0   Use for DMS and Implications The use of a DWHR device reduces the amount of energy a household uses to heat water for showering. Utilities looking to reduce household energy demand could incentivise the install ation of DWHR devices by providing a rebate of the purchase price. Since the NPV calculation for the average house is negative, the average homeowner would not realize a savings by installing a DWHR device based on current conditions. A rebate could lower the cost and create a positive NPV, making the installation of a DWHR device beneficial for the average Canadian.  The difficulty is in ensuring that the location where the device is installed will receive sufficient usage to justify the incentive from the utility provider’s point of view. Most showers take place in the early morning[28] , so a DWHR de vice could also serve as method of peak shaving.  The re is the possibility that the installation of a DWHR device could drive higher consumption rates. If the user knows that the shower has a  DWHR device installed, they may be more inclined to take a longer shower. If users normally wait until the hot water temperature begins to fall as a result of the water heater tank emptying , this would take longer to occur if a DWHR device is being used. It may be possible for a HWH to keep up with a shower if a DWHR de vice is installed.     3 1   Other Considerations There are some additional factors that should be considered when looking at this analysis. The amount of use that the DWHR device receives is treated as a factor of household size. The analysis assumes that all members of a household use a common shower where the DWHR device is installed. The number of showers within a home will generally scale with the number of bedrooms, so a larger household will not necessarily mean that an individual shower will be used more f requently. Newer homes are also more likely to have a higher number of showers within them. The analysis also assumes that each member of the household bathes by showering. While this is common for Western cultures, in many parts of the world taking baths is more common. For the installation that was described in this project, there would not be any energy savings realized with taking a bath due to the temporal gap between fresh water flow and drain water flow. Lastly, the efficiencies of how water systems and flow rates of showers that were used in the analysis reflect the standard for modern homes. Older homes with original equipment and fixtures would receive greater benefits due higher energy consumption for equivalent heat production out of the water he ater, and also higher shower head flow rates.     3 2   Conclusions Based on the preceding analysis, the conditions necessary for the economic use of a DWHR device have been determined. Based on the configuration of the analysis , the average Canadian household wo uld not see a benefit from installing this DWHR device. Generally speaking, the current low costs of natural gas make the economics of using a DWHR device in a h ousehold with a natural gas water heater difficult.  If natural gas prices return to more histor ical rates, this could change.  The br eak - even analysis revealed that  a household size of 4 or more with an electric hot water heater would benefit from installing a DWHR device. Canada has more than 3 million households of 4 or more people [26] , which would benefit from the installation of a DWHR device under current conditions. This analysi s was specific to the conditions mentioned, and broader adoption could be possible ( ex. different installation configuration ).  Significance of Work Preceding  this work, little research has been done on the practicality of installing DWHR devices . The scope of this project was limited to one set of tests performed on one model of horizontal DWHR device. Cha nges to installation options such as slope, or installation configurations, could potentially increase the performance of the DWHR device to the point wh ere it would be economically advantageous to be installed  in the average Canadian home. There is a large opportunity for energy and cost savings which could be achieved if DWHR devices are installed in suitable locations.     3 3   Recommendations M y recommendati on for further work to be done in this area would be to have the device installed in  an actual shower for real world test results. While the setup of the testing performed attempted to mimic actual shower conditions as closely as possible, it is still not an exact match. The drain water contains other additives other than water, including soaps and shampoos, as well as dirt and debris.  Furthermore, my assessment did not monitor the pressure drop through the DWHR unit, which is part of the NRCAN testing  protocol for vertical  DWHR system. Future research should include pressure drop through DWHR units to ensure they do not negatively impact the remainder of the system.  Monitoring an installation in an actual shower will also allow an assessment of maintenance issues and costs and the lifetime of a DWHR device. The economic assessment was based on a lifetime of 15  years with no maintenance costs, and it is unknown whether this is representative of actual conditions. Maintenance fees or a shorter (or longer) life time will impact the economic assessment of installing such devices.   Works Cited [1]  Natural Resources Canada, “Energy Use Data Handbook Tables, 1990 and 2001 to 2010,” 17 - Jan -2013 . [Online]. Available: http: //oee.nrcan.gc.ca/corporate/statistics/neud/dpa/showTable.cfm?type=HB&sector=res&juris=00&rn=1&page=5&CFID=29287 61 7&CFTOKEN=2a90e5d55c648a17 - 65B13E9B - DFDB - 4646 -0 94 78C8527 243 86 4 . [Accessed: 24 - Jan - 2013 ].  [2]  M. Thomas, A. C. S. Hayden, O. Ghiricociu, R. L. D. Cane, and R. Gagnon, “A New Study of Hot -Water Use in Canada.,” ASHRAE Transactions , vol. 117, no. 1, pp. 673 –6 82 , May 2011 .  [3]  W. B. DeOreo and P. W. Mayer, “The End Uses of Hot Water in Single Family Home from Flow Trace Analysis,” 2001. [4]  B. Schoe nbauer, D. Bohac, and M. Hewett, “Measured Residential Hot Water End Use.,” ASHRAE Transactions , vol. 118, no. 1, pp. 872 – 88 9 , May 2012 .  [5]  A. Cooperman, J. Dieckmann, and J. Brodrick, “Drain Water Heat Recovery.,” ASHRAE Journal, vol. 53, no. 11, pp. 58 – 64 , Nov. 2011 .  [6]  C. Zaloum, M. Lafrance, and J. Gusdorf, “Drain Water Heat Recovery Characterization and Modeling,” 2007. [7]  L. T. Wong, K. W. Mui, and Y. Guan, “Shower water heat recovery in high - rise residential buildings of Hong Kong,” Applied Energy , vol. 87, no. 2, pp. 703 –7 09 , Feb. 201 0 .  [8]  S. Bartkowiak, R. Fisk, A. Funk, J. Hair, and S. J. Skerlos, “Residential Drain Water Heat Recovery Systems: Modeling, Analysis, and Implementation,” Journal of Green Building , vol. 5, no. 3, pp. 85 –9 4, Aug. 20 10 .  [9]  BC Hydro, “BC Hydro Residential Rates.” [Online]. Available: https://ww w.bchydro.com/accounts - billing/customer - service- residential/residential - rates.html. [Accessed: 01 - Apr - 2013 ].  [10 ]  Enmax, “Enmax Residential Rates.” [Online]. Available: http://w ww .enmax.com/easymax/residential/questions/Current+Prices/Current+Prices.htm. [Accessed: 01 - Apr - 2013 ].  [11 ]  Saskatoon Light and Power, “Saskatoon Light and Power Residential Rates.” [Online]. Available: http://www .saskatoon.ca/DEPARTMENTS/City Clerks Offic e/Documents/bylaws/268 5 .pdf. [Accessed: 01 - Apr - 2013 ].  [12 ]  Manitoba Hydro, “Manitoba Hydro Residential Rates.” [Online]. Available: http://www .hydro.mb.ca/regulatory_affairs/energy_rates/electricity/current_rates.shtml#residential. [Accessed: 01 - Apr - 201 3 ].   [13]  Ontario Energy Board, “Toronto Hydro Residential Rates.” [Online]. Available: http://www .ontarioenergyboard.ca/OEB/Consumers/Electricity/Electricity Prices. [Accessed: 01 -Apr - 2013 ].  [14 ]  Hydro Quebec, “Hydro Quebec Residential Rates.” [Online]. Available: http://www .hydroquebec.com/residential/understanding - your - bill/rates/residential - rates/rate -d/. [Accessed: 01 - Apr - 201 3].  [15 ]  Saint John Energy, “Saint John Energy Residential Rates.” [Online]. Available: http://www .sjenergy.com/cms/residential_rates . [Accessed: 01 - Apr - 2013 ].  [16 ]  Nova Scotia Energy, “Nova Scotia Power Residential Rates.” [Online]. Available: http://www .nspower.ca/en/home/aboutnspower/ratesandregulations/electricityrates/domesticservicetariff.aspx. [Accessed: 01 - Apr - 201 3 ].  [17 ]  Mariti me Electric, “Maritime Electric Residential Rates.” [Online]. Available: http://www .maritimeelectric.com/about_us/regulation/reg_irac_regulations_det.aspx?id=136&pagenumber=63. [Accessed: 01 - Apr - 201 3 ].  [18 ]  Newfoundland Power, “Newfoundland Power Residential Rates.” [Online]. Available: https://secure.newfoundlandpower.com/AboutUs/PDF/ratebook.pdf. [Accessed: 01 - Apr - 2013 ].  [19 ]  Fortis BC, “Fortis BC Residential Rates.” [Online]. Available: http://www .fortisbc.com/NaturalGas/Homes/Rates/Pages/Lower - Mainland. aspx. [Accessed: 01 -Apr - 2013 ].  [20 ]  SaskEnergy, “SaskEnergy Residential Rate.” [Online]. Available: http://www .saskenergy.com/residential/resrates_curr.asp. [Accessed: 01 - Apr - 201 3 ].  [21 ]  Manitoba Hydro, “Manitoba Hydro Residential Rates.” [Online]. Available: http://www .hydro.mb.ca/regulatory_affairs/energy_rates/natural_gas/current_rates.shtml. [Accessed: 01 - Apr - 2013 ].  [22 ]  Enbridge Gas, “Enbridge Gas Residential Rates.” [Online]. Available: https://ww w.enbridgegas.com/homes/accounts - billing/residential - gas- rates/purchasing - gas-from - enbridge.aspx. [Accessed: 01 - Apr - 2013 ].  [23 ]  Gaz Metro, “Gaz Metro Residential Rates.” [Online]. Available: http://www .grandeentreprise.gazmetro.com/data/media/conditionsservicetarif_an.pdf?culture=en- ca. [Accessed: 01 - Apr - 2013 ] .  [24 ]  Enbridge Gas New Brunswick, “Enbridge Gas New Brunswick.” [Online]. Available: https://secure.naturalgasnb.com/CMS/site/media/naturalgasnb/Handbook of Rates and Distribution Services -  Oct 1 2012 .pdf. [Accessed: 01 - Apr - 2013 ].  [25 ]  Heritige Gas, “Heritige Gas Residential Rates.” [Online]. Available: http://www .heritagegas.com/residential/residential - rates.html. [Accessed: 01 - Apr - 2013 ].   [26]  Statistics Canada, “2011 Census of Population and Statistics,” 2011. [27]  Natural Resources Canada, “Survey of Household Energy Use,” 2007. [28]  C. R. Wilkes, A. D. Mason, and S. C. Hern, “Probability Distributions for Showering and Bathing Water - Use Behavior for Various U.S. Subpopulations,” Risk Analysis , vol. 25, no. 2, pp. 317 –3 37 , 200 5 .  [29 ]  PA Consulting Group , “State of Wisconsin Public Service Commission of Wisconsin,” 2009. [30]  EcoDrain, “EcoDrain A1000 Installation Manual.” .     Appendix A – Calculations Heat t ransfer rate (23.1℃− 11.1℃) ×3.87 𝐿60 𝑠×4.185 𝑘𝐽𝐿 ∙ ℃= 3.284 𝑘𝐽𝑠= 3.284 𝑘𝑊 Per sho wer energy savings (𝑊𝑎𝑟𝑚 𝑢𝑝 𝑡𝑖𝑚𝑒 × 𝑤𝑎𝑟𝑚 𝑢𝑝 𝑟𝑎𝑡𝑒) + (8.5min−𝑤𝑎𝑟𝑚 𝑢𝑝 𝑡𝑖𝑚𝑒) × 𝑠𝑡𝑒𝑎𝑑𝑦 𝑠𝑡𝑎𝑡𝑒 𝑟𝑎𝑡𝑒 72 60 𝑚𝑖𝑛𝑢𝑡𝑒𝑠 × 1.52𝑘𝑊 + 7.3 𝑚𝑖𝑛𝑢𝑡𝑒𝑠 × 3.284 𝑘𝑊 = 25.8 𝑘𝑊 ∙ 𝑚𝑖𝑛 = 0.43𝑘𝑊ℎ  Annual  energy  savings 0.43𝑘𝑊ℎ × 2.59 𝑠ℎ𝑜𝑤𝑒𝑟𝑠𝑑𝑎𝑦× 365 𝑑𝑎𝑦𝑠 = 406 𝑘𝑊ℎ Annual e lectric cost savings 406 𝑘𝑊ℎ ×9.41¢𝑘𝑊ℎ×$100¢= $38.25 Annual n atural gas cost savings 406 𝑘𝑊ℎ × 3.6𝑀𝐽𝑘𝑊ℎ×𝐺𝐽1000 𝑀𝐽×$7.13𝐺𝐽= $10.42    Appendix B – NRCAN DWHR testing procedure     		 					 !"			 !"	# !"			 !" # 				 !"	$%&'()**+( !"	#					,	###,-./ #				0		11#	#	#	213"$/	#1	))%4 &'(2		#31	)$ (#5						##&6	/	*$$+,  +-7 !"			+.7 !"							++7 !"		4$	8#/0$) !"			1#	4  !"		0# ###%&'()**+( !"	011# #			1# #	#/###/	##	2,													1#1## 9#		#	:	 !"#	1###+;)))+-<1##%!#'=>#;>1##/, !"	4 	 !"	# #		 !"	1##1  	 !"#					1#%)1#	1	#   	?10?	0 ?	0 ?0 ?0 	?1	0 ?	0 ?		0 ?	: !"	## 1#/"	 !"				#		#			 !"	1#1)$$3"$. !"		#				#&&		#			#@;>  $1#1!"+)$4$3+# 5$:!.	;> !.	'=>: 6&-<1#69#		#5#	##5		#	#1#7+$$"/!	#1#			#		1#7# #	#					&'1#7#/!#			# !"1	#	#1#.$"$$###		#1	1		#	#.	A&B	#	#1#8")$$3	#5 !"	#&6.				#:5	 !"212C8C33# !"*&	#C8C	#'*&# !"C2C	#=)*  2#28 !D	/ !"		 			E		#/		#&)*	#		#2#/#		 !".					#			  $1#8")$$3# 5$ $ +.!	 @;> A)> E1		+;>: +;)))+-<A*&-< #,$ D A@> 2#	2#	 9		 !"	A&> .	! .*& E		F2# !",&*		 !"E		$	#	#		E	2	A*@> E1				#/	F	E	2	A*@&B E1			:E	2	A@B E1		98 A&B E1		:			1# "#4 		#  !"/# -< B	 	/F 21 !"	21  -9-&*'41# 9"$-""!#  	-9.&2*'$)"9	#/				&=) 	2	G<3*)H		@ :2		$:8+=*&	#G<3)B' 		#	#				$ FI)***83)**II		G<3*@&B	*)**2						#+ ./	I)%@99@%*-$/#& .	21			1		'=>11&3)@*F9@+*= F	2					#521/				% .23	31				/			; .!/#			;>#	#23	/				6 . !"*=# !"#		28	#		  -9+&*'""$"!1#7#'   Appendix C – EcoDrain A1000 DataSheet   All rights reserved - Ecodrain Inc.Page 1 A1000HEU_DATA.pdfinfo@ecodrain.comwww.ecodrain.comHIGH PERFORMANCE HEAT EXCHANGERA1000 HEAT EXCHANGER DATA SHEETDesign Part identificationABCDAABEBEcodrain Inc. offers a 10 YEAR limited performance warranty and a four year guarantee free of factory defects, provided the device is used under normal shower drain water heat recovery applications (and no other application) and is used with potable water, free of excessive iron  or hardness inducing salts and minerals. Defects from shipping, installation, repackaging, lackof proper maintenance of adjoining appurtenances and system connected fluid flow devices, alterations, misuse, mishandling even by plumbing contractors, the house owner or other service personnel, will not be covered.Ecodrain Inc. will not accept liability or responsibility for any value of consequential damages (no matter what is the source) resulting in whatever replacement value, caused by whatever reason.It is the responsibility of the Installation personnel to ensure full compliance to local codes and laws.No other warranties/guarantees are implied or suggested beyond what is stated above.In order to avail of additional accessories, like filter baskets, attachments, or types of connectors, the company is available for further consultation.Warning:Preheated cold water from a shower water heat exchanger can accidentally cause scalding if not properly adjusted for temperature before use. Hot water can cause third degree burns in6 seconds at 60C (140F), and in 30 seconds at 54C (130F). In households where there are children, physically challenged individuals, or elderly persons, mixing valves at the point of use are recommended as a means to reduce the scalding potential of hot water. For your safety and to avoid damage caused by improper installation, this shower heat exchanger should be installed by a Certified Licensed Professional, and meet all applicable building codes. Ecodrain Inc.cannot be held responsible for accidental injuries resulting from improper or careless use of hot water. A1000 Cut out viewwith interior tubingA1000 Complete viewwith drain and p-trap connectionGrey water connectionCold water connectionDouble wall tube assemblyFG P-trap and shower floor drainDEGFDrain and connector to fitexisting grey water connectionAtmospheric ventE ShellThe A1000 Heat Exchanger is symmetric.Either grey water connector can function as the grey water inlet.Either cold water connector can function as the cold water inlet.For best performance, the cold water line should be connected such that cold water enters the device at the end opposite from which grey water will enter the device. CAll rights reserved - Ecodrain Inc.Page 2 A1000HEU_DATA.pdfinfo@ecodrain.comwww.ecodrain.comHIGH PERFORMANCE HEAT EXCHANGERA1000 HEAT EXCHANGER DATA SHEETA4 1/2”(114 mm)BINSTALLATION SLOPE PERFORMANCE CHARACTERISTICSModel Box TubeLengthConnectorA1000  -  A  -  MC  -  48  -  2Check with local codes in order to validate the minimum angle required. Note that heat transfer performance will increase as the tilt angle increases. This can boost heat exchanger performance by 5%-10%. The reason is that at a higher tilt angle, the waste water travels faster. This generates turbulence in the waste water flow and as a result the waste water gives off heat at a higher rate. With the A1000 unit, a maximum slope of 75 o is recommended to allow an efficient heat transfert. Beyond that slope, some of the grey water will travel down the center of the exchanger and will have reduced contact with the heat transfer tubes. A1000 Heat Exchanger to be installed leveled in order to deliver optimal performance6 5/8”(168 mm)leveledHOW TO SPECIFYgreywaterinletgreywateroutletcold wateroutletcold waterinletAB75°maximalrecommendedslope30°1°  (1/4”:12”)minimalslopeHeat exchanger performance varies based on several factors including installation configuration, cold water temperature, shower temperature, shower usage, type of water heater and cost of energy. Please consult website for greater performance details.MATERIALS AND DIMENSIONS OPTIONSA1000  ModelAABSBoxCCopperMCtype M copperTubeLCtype L copperSSStainless Steel48 inchesHeat TransferLengthOverallLength72 inches96 inchesConnector(B)PPVC4 inches2 inches3 inches56 inches80 inches104 inches

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