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Evaluation of two building air cleaning systems at UBC Life Science Building based on environmental impact… Hashemi, Seyedeh Zahra; Bao, Jie Feb 7, 2012

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   Evaluation of two building air cleaning systems at UBC Life Science building based on environmental impact and cost analysis  Author: Seyedeh Zahra Hashemi ,  Jie Bao Instructor: Dr.Tony Bi, Jeff Giffin, Brenda Sawada         UBC Centre for Interactive Research on Sustainability (CIRS) CHBE484 1  Contents  1.0 Introduction ............................................................................................................................... 2 1.1 Goal and Scope ......................................................................................................................... 3 2.0 Cost analysis ............................................................................................................................. 3 2.1Method ................................................................................................................................... 3 3.0 Environmental Impact assesment ............................................................................................. 6 3.1 Functional Unit ......................................................................................................................... 7 3.2 System Boundary ...................................................................................................................... 7 3.3 Emission Inventory ................................................................................................................... 7 3.3.1. Emissions during material manufacture ........................................................................ 7 3.3.2 Emissions during transportation from manufactures to UBC ........................................ 9 3.3.3 Emissions during disposal process ............................................................................... 11 3.4 Comparison of the old filters and the new one.................................................................... 12 3.5 Impact assessment ................................................................................................................... 13 4.0 Conclusion .............................................................................................................................. 15 5. References ................................................................................................................................. 16             2   1.0 Introduction It is an important process to fresh the air in Life Science Center in UBC, which requires quantities of energy and labor work. The air passes through the filters, getting purified to some degree. And then it will pass through the coil system to be heated or cooled. In the previous method, two kinds of filters were used. One is pre-filter, and the other one is box filter, which requires to be replaced every three months and every year correspondingly. Now, the Nalco Company provides filter replacement to take the place of previous two filters and coil cleaning procedure as well. The new filters should be replaced every 2 years.  Switching from previous filter system to new one reduces the costs, including the fan energy required to blow the air through the filters, waste disposal cost and the labor cost to replace the filters. The previous filter system contains four hundred pre-filters, 24x24x2 Red Excel filters, and 400 box filters, 24x24x12 MVP. In the new system, 400 24x24x2 3M filters are replaced. From January 9 th  to 14 th  2012, Nalco cleaned coils and changed the air filters on 11AHU’s(2,3,5,6, 9,27,27A,28,28A,29,29A,34) at the Life Sciences Centre. Nalco also replaced the air filters on AHU #10 and the main plenum servicing all 34 AHU’s.  Figure 1.Pre filter, Box filter, 3M filter  3  1.1 Goal and Scope The purpose of this work is to compare the environmental impacts of previous filter system including pre-filter and Box filter with new filters (3M filters) in Life science building of the University of British Columbia. Furthermore, the cost analysis has been done to investigate whether it was economical to replace the previous filters system with new filters (3M). For cost analysis, filter cost, energy cost, labor cost to change filters, and disposal cost have been considered. For the environmental Impact, The analysis will focus on the emissions resulting from filter raw material production, filter transportation from factory to UBC, and filter transportation from UBC to disposal field. 2.0 Cost analysis 2.1Method Input data for this analysis was obtained in two stages: before January 10 th   and after January 15 th  The Fan power has been measured for 13 units including units – 2,3.5.6.9.10.27.27a,28,28a,29,29a,34 .Before January 10 th  the pre-filter and Box filter were used as the air filters in Life Science Center. The project was carried out during the week of January 10 th  – 15th. This project included coil cleaning and filter changing. Pre filter and box filter were replaced with 3M filters. For cost analysis, project cost includes coil cleaning, price of filters, and BC hydro incentive. In this study, fan energy consumption, filter cost, labor cost for replacement of filters, and disposal cost will be considered. Table 2.1 summarizes the fan energy consumption for each unit before January 10 th  and after January 15 th .     4  Table 2.1 Fan energy consumption before Jan. 10th and after Jan 15 th    Before Jan 10 After Jan 15 Unit  KWs(average value) kwh/yr. KWs(average value) kwh/yr. 2 62.557 547999.057 60.098 526462.247 5 7.138 62531.595 7.181 62902.144 6 7.138 62531.595 7.181 62902.144 9 14.827 129889.338 12.171 106615.945 10 15.213 133270.610 13.816 121027.634 27 24.122 211309.683 18.453 161650.47 27A 22.811 199832.419 17.923 157003.202 28 32.259 282591.117 27.843 243904.768 28A 29.062 254582.419 25.773 225768.326 29 37.290 326659.787 30.783 269663.109 29A 37.679 330066.463 31.465 275633.926 sum   2541264.086   2213533.915  Energy cost is estimated as 0.05 $/KWh. The difference between energy consumption before January 10 th  and after January 15 th  will result in Energy saving (Table 2.2). Table2.2 Fan energy saving Fan Energy saving Cost,$ Energy, kwh/yr. 16387 327730.171  Pre filter, Box filter, and 3M filter cost 6.75$/filter, 73.90$/filter, and 75.90$/filter respectively. Pre-filters, box filters, and new filters should be replaced every 3 months, every one year and every two years respectively. Saving resulting from labor cost and disposal cost is due to different life time of filters. Also, it should be considered that 800 filters, 400 pre-filters and 400 box filter, were used in previous filter system and only 400 3M filters were installed. Furthermore, different filter cost and 5  different life time of filters cause the saving in filter purchases after switching from previous filter system to new one. It is obvious that labor cost is much more for previous filter system including pre-filters and box filters than new filters in that new filters have been replaced each two years. The cost analysis including filter cost, labor cost, and disposal cost are shown below in table 2.3. Table2.3Energy saving (Filter cost, Labor cost, Disposal cost)  The project cost includes coil cleaning labor cost, 3M filter cost. BC Hydro is also providing incentives based on energy payback from these programs which can help fund this work and provides for a very short payback period. Table 2.4 provides the project cost. Table 2.4.Project cost Project Cost Cost($) Coil cleaning 16500 3M filter 29519 Bc hydro incentive -12750 Total Costs 33269 Saving per year saving($/yr.) energy saving 16387 Avoided filter purchases 4163 Avoided labor cost 1754 Avoided disposal cost 3968 Total saving/year 26272 6  Figure 2.1 Saving distribution   The reduction in fan energy consumption has the major impact on saving and the impact of disposal cost, labor cost, and filter purchases on saving is nearly the same. Based on the project cost and savings the payback period is nearly one year (Figure 2.1). 3.0 Environmental Impact assesment There’s no doubt that cost analysis will be a major concern when choosing the filters. However, as environmental issues have been more and more emphasized, the environmental impact assessment should also be carefully considered. Unlike other life cycle analyses which consist of numbers of factors, in our case, there are just three main parts that we take into consideration including emissions during filter production, emissions during transportation of filters from factory to UBC, and transportation of used filters from UBC to disposal field . The three types of filters we study here are: pre-filter, box filter and new filter. Detailed information of these filters is listed below:     Avoided filter purchases Avoided disposal cost Avoided Labor Cost Energy Saving 7  Table 3.1 Information of filters (American Air filters) Name Type Company Pre-filter Red Excel Filter shop Box filter MVP Freudenberg New filter 3M American Air Filter  3.1 Functional Unit For the purpose of this study, a functional unit needed to be selected to provide equivalency amongst each system and enable comparison. For this analysis, the functional unit was set as per two years filter consumption for Life Science Center. 3.2 System Boundary The boundary for Environmental impact assessment will be considered from material production to disposal of filters. The emission releasing from filter production is not included in this LCA because it is negligible in comparison with martial production. 3.3 Emission Inventory 3.3.1. Emissions during material manufacture Emissions during the production may be divided into two parts, one is during the production of raw materials of filters, and the other one is during the manufacturing of filters. However, compared to the emissions from the production of raw materials, the later one seems negligible. As a result, only emissions during the production of raw materials are considered. Table 3.2 shows the components of each filter, and the composition of each component, as well.       8   Table 3.2 Components and compositions of filters Pre-filter Component Weight fraction, % Weight, kg Synthetic fibers 100% 0.56 Box filter Component Weight fraction, % Weight, kg Micro-glass fiber 30.87 0.92 Halogen-free plastic 69.13 2.06 New filter Component Weight fraction, % Weight, kg Ultra-fine glass fiber media 51.03 0.74 2” plastic 48.97 0.71  Table 3.3 shows the emission factors of each component. Table 3.3 Emission factors of each component, g/kg-component (U.S. Life Cycle Inventory Database, K.G. Harding et al., 2007, Jyri Seppala et al., 2002. S.V. Joshi, 2004)  Pre filter Box filter New filter Synthetic fiber Glass fiber Halogen-free plastic Ultra-fine glass fiber media Plastic CO2 2.04 2.04 19.30 2.04 19.3 CO 0.80 0.80 0.12 0.80 0.12 NOx 2.93 2.93 0.014 2.93 0.014 SOx 8.80 8.80 0.023 8.80 0.023 PM 1.04 1.04 0.0001 1.04 0.0001  Then we can get the emissions of these three filters during the production.  9    Table 3.4 Emissions from material production, g/filter  Pre filter Box filter New filter Synthetic fiber Glass fiber Halogen-free plastic Ultra-fine glass fiber media Plastic CO2 1.14 1.88 39.76 1.51 13.70 CO 0.45 0.73 0.25 0.59 0.085 NOx 1.64 2.70 0.03 2.17 0.0099 SOx 4.92 8.10 0.05 6.51 0.016 PM 0.58 0.96 0.0002 0.77 0.000071  Table 3.5 Emissions from two systems for two years, g/2 years  Old system New system CO2 36963.52 6085.04 CO 2220.16 270.88 NOx 7430.11 871.26 SOx 22284.30 2611.33 PM 2629.28 307.87  3.3.2 Emissions during transportation from manufactures to UBC While filters are transported, the vehicles may give rise to serious emissions, like greenhouse gases, NOx, SO2, etc. Based on the emission factors we get from the internet, the emissions of these pollutants will be calculated hereby: emissions=emission factors ×distance. Also, we assume that the vehicles are all large diesel trucks, with a full load of 20 tones. For Life Science Center, there are 400 filters working inside the building. Each pre-filter can last for three months, box filter for one year, while new filter can be used for two years. We consider the emissions based on two years’ usage. Therefore, 3200 pre-filters, 800 box filters and 400 new 10  filters are considered. Table 3.6 shows the location of factories and the distance from factories to UBC. Table 3.6 Distances from factory to UBC Filter Address distance ,km Pre-filter 5711-103A Street, Edmonton, Alberta, Canada 1179 Box filter 2975 Pembroke Road, Hopkinsville, KY, USA 4073 New filter 10300 Ormsby Park Place Suite 600 Louisville, Kentucky, USA 3223   Table 3.7 Emissions of three filters during transportation from factory to UBC  Emission factors g/km Emission, g Pre-filter Box filter New filter CO2 1419 1673001 5779587 4573437 CO 0.9 1061.1 3665.7 2900.7 NOx 7.74 9129.88 31540.29 24958.11 SOx 1.12 1320.48 4561.76 3609.76 PM 0.11 125.27 432.76 342.44 VOC 0.17 198.96 687.32 543.88  Table 3.8 Emissions Inventory during Transportation from Factories to UBC, g/2 years  Old system New system CO2 7452588 4573437 CO 4726.8 2900.7 NOx 40670.18 24958.11 SOx 5882.24 3609.76 PM 558.03 342.44 VOC 886.28 543.88  11  3.3.3 Emission during filter usage  3.3.4 Emissions during disposal process As for the usage period of filters, the pre-filter should be changed every three months, box filter can last one year, and the new filter is supposed to be useful for two years. All of them are not recyclable, therefore while disposing the used filters, emissions do exist. In Vancouver, the Cache Greek landfill is located North Shore Transfer Station- 30 Riverside Drive, North Vancouver BC, 23.4 km away from UBC. Again, it is assumed that large diesel trucks are used as vehicles. The emissions are as follows:  Table 3.9 Emissions of three filters during disposal process, g/2 years  emission factors, g/km emission, g Pre-filter box filter new filter CO2 1419 33204.6 33204.6 33204.6 CO 0.9 21.06 21.06 21.06 NOx 7.74 181.20 181.20 181.20 SOx 1.12 26.21 26.21 26.21 PM 0.11 2.49 2.49 2.49 VOC 0.17 3.95 3.95 3.95  Table 3.10 Emissions Inventory of Transportation during disposal process, g/2 years    old system new system CO2 66409.2 33204.6 CO 42.12 21.06 NOx 362.41 181.20 SOx 52.42 26.21 PM 4.97 2.49 VOC 7.90 3.95 12   3.4 Comparison of the old filters and the new one Based on the previous emissions we get, now we’ll make a summation of the emissions from production and transportation for the old and new filter systems, respectively. The results are as follows: Table 3.11 Summary of emissions of two systems  emissions during production, g emissions during transportation, g total emissions, g  old system new system old system new system old system new system CO2 36963.52 6085.04 7518997.2 4606641.6 7555960.7 8070398.4 CO 2220.16 270.88 4768.92 2921.76 6989.08 4109.36 NOx 7430.11 871.26 41032.58 25139.31 48462.70 29947.89 SOx 22284.30 2611.33 5934.66 3635.97 28218.96 13668.8 PM 2629.28 307.87 563.00 344.93 3192.28 1010.57 VOC 0 0 894.17 547.83 894.17 547.83  Figure 3.1 Emission comparison  0 10000 20000 30000 40000 50000 60000 CO NOX SOX PM VOC OLD SYSTEM NEW SYSTEM 13   Table 3.12 Comparison of two systems in emissions Emission Percentage of reduction, % CO2 38.95 CO 54.32 NOx 46.33 SOx 77.86 PM 79.55 VOC 38.73  3.5 Impact assessment  Once the emissions have been aggregated for the life cycle of filters, the environmental impacts can be determined. Table 3.13 contains the impact indexes used to evaluate the environmental and health impacts associated with whole life cycle of filters. Impact indexes were taken from IPCC 4th assessment report, 2007. GWP(Global Warming Potential), SFP(Smog Formation Potential), and ARP( Acid Rain Potential) are all measures of environmental impacts. Table 3.13 Environmental Impact indexes Environmental Impact Index emission GWP ARP SFP CO2 1 0 0 CO2 1.9 0 0 NOX 27 0.7 0 SOX 0 1 0 PM 0 0 0 VOC 0 0 1     14  Table 3.14 Environmental Impacts  Old system New system Reduction, % GWP, g CO2- eq 8877733 5321078 40.06 ARP, g SO2-eq 62142.85 24454.7 60.65 SFP, g ORG-eq 894.17 547.83 38.73   Based on the GWP, SFP, ARP, we can know that the new system will help greatly in the reduction of SFP and ARP, and the GWP remains almost the same (Table 3.14).    15  4.0 Conclusion Switching from pre-filters to the new filter system reduce labor cost, waste disposal cost, and filter cost. The payback period is nearly one year so based on cost analysis; it seems that it is reasonable to change the old system to new one. Moreover, according to the total emissions, compared to the old system in which pre-filter and box filter are used  together, the new system(3M filter) only consisting of 3M filter can reduce the emissions of CO, NOx, SOx, PM and VOC significantly. The new system also reduces CO2 emission by 38.95%. The exchange of pre-filter and box filter with new filter will help to reduce the emissions to the ambient environment Besides Cost analysis and Environmental Impact, there are other factors which should be investigated before filter selection. For instance, another major problem of previous filter system was that they occupy a huge storage place before transportation from UBC to disposal place. The old filters occupy 6 times of the storage space that 3M filters occupy. The filter performance is another factor which should be evaluated. Evaluation of 3M filter performance needs much more time.      16  5. References  American Air Filters. Air Filtration Products and Capabilities, Advanced Solutions for the Removal of Airborne Particulate and Gaseous Contaminants  Assessing the effects of freight movement on air quality at the national and regional level. Appendix B: Estimation of future truck emissions. Available at: http://www.fhwa.dot.gov/environment/air_quality/publications/effects_of_freight_movement/ch apter07.cfm  IPCC 4th assessment report, 2007  Jyri Seppala, Sirkka Koskela, Matti Melanen, Matti Palperi, The Finnish metals industry and the environment. Resources, Conservation and Recycling 35 (2002) 61-76.  K.G. Harding, J.S. Dennis, H. von Blottnitz, S.T.L. Harrison, Environmental analysis of plastic production processes: Comparing petroleum-based polypropylene and polyethylene with biologically-based poly-β-hydroxybutyric acid using life cycle analysis. Journal of Biotechnology 130 (2007) 57-66.  S.V. Joshi, L.T. Drzal, A.K. Mohanty, S. Arora, Are natural fiber composites environmentally superior to glass fiber reinforced composites?. Composites: Part A 35(2004) 371-376.  U.S. Life Cycle Inventory Database. Available at: https://www.lcacommons.gov/nrel/search  

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