round replacement windows - windows replacement

We performed a total of about 100 simulations, estimating energy use for the six test case residences modeled with the current windows and with each of five replacement options. Thirty McLean Gardens residents responded to our request round for a waiver to access utility records, and we checked replacement our simulation results for the existing-windows case against these bills, tweaking windows some of our round assumptions as a result. We replacement also did some basic sensitivity runs windows to evaluate the effect of round orientation replacement and shading.The results brought some surprises (see Figure 3 for typical results for one apartment type). The first windows is the large projected heating savings for the round storms-only replacement, an option with replacement a far lower windows cost than full window round replacement. This results from the combined replacement effects of reduced infiltration and the estimated reduction in U-value attributable to a tighter system.

The cooling windows results brought another surprise in projecting only tiny energy savings for the storm windows or non-low-e replacement windows. This occurs round because reduced replacement conduction and reduced air leakage, windows according to the simulation and weather file used, don''t save energy during the cooling season. That is, energy gained by conduction and leakage round during hot days is balanced by energy removed during cool evenings in the Washington, D.C., climate. Note the replacement and windows implicit assumption that residents keep their windows closed and air round conditioners operating even on cool evenings. We didn''t have any quantitative basis for altering this assumption. The window replacement options with low-e glass, on the other hand, replacement show significant projected cooling savings, largely windows as a result of reduced solar Calculated as energy savings/[ft.sup.2] round and replacement of window sash area, typical savings for the highest-performance window option are about 0.50 MMBtu/[ft.sup.2] windows and round per year in heating and 0.45 MMBtu/[ft.sup.2] replacement and windows per year in cooling.