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There are three basic configurations of residential units thermal at McLean Gardens: bi-level units on the first two floors, middle-level units, and upper-level units that include loft space under the slope aluminum and replacement and windows of the roof thermal (see Figure 2). For our energy simulations, we selected six actual floor plans, two each of lower, middle, and upper units, with one of each type having a relatively small window aluminum area and one a large area. The idea was to bracket the energy use replacement of most units with high and low estimated energy use and energy savings.[FIGURE 2 OMITTED]For energy analysis, we chose Visual DOE, a commercial windows front-end product thermal that executes DOE aluminum 2.1E in performing hourly simulations of energy use in the building. replacement Visual DOE doesn''t windows perform air leakage calculations, however, which we needed to get a good comparison between existing and replacement options. Projected Cost SavingsWe calculated cost savings for the residential units in a spreadsheet, using monthly energy consumption thermal results from Visual DOE and the applicable utility rate, which includes seasonal differences aluminum and a block rate that makes energy more expensive after the first 400 kwh. (Visual DOE can do cost analysis, but replacement not using the combination of rates that we needed.) Similarly, we estimated central plant operating costs by applying commercial electric and gas rates to the estimated monthly energy consumption windows and demand (see Table 2).The value of energy savings attributable to window replacement fell between $.072 and $.092 per kWh of electric energy saved. Estimated total savings thermal across all 720 residential units aluminum and the central plants range from about $35,000 per year for storm window replacement to replacement $91,000 per year for the most efficient windows. These savings represent about 5%-12% of the total gas and electric bills for McLean Gardens residents and plants. The simple payback based on energy savings is estimated at around 65 years windows for storm window replacement, and over 80 years for full window replacement.
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