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Cleaning. The existing window system is almost impossible to clean thoroughly from inside the building. As a result, many residents pay for professional cleaning, at a cost of $100 or more, once or twice a year. Tilt-in replacement windows, and brynmawr and replacement elimination of the separate storms, would allow relatively easy cleaning of all surfaces from the interior. Thus, residents who drop professional cleaning in favor of doing it themselves, and consider it a free-time activity, might save more in cleaning costs than in energy costs.Ventilation. Although the McLean windows Gardens brynmawr buildings don''t have mechanical ventilation systems, reports of excess moisture accumulation replacement and windows and mold growth are uncommon. The leaky windows are undoubtedly a major factor in providing natural ventilation rates sufficient to limit moisture accumulation during cold weather. (Air conditioning limits moisture accumulation brynmawr and replacement during the summer.) Window replacement would significantly reduce overall building infiltration. windows Our project did not include measurement brynmawr of overall building leakage, but we believe that overall natural infiltration rates would be cut by more than 50%, and that the resultant increase replacement in interior humidity and condensation would probably cause paint failure and mold growth in some units. This windows issue could be addressed directly through the installation of mechanical ventilation systems. The risk of excess moisture accumulation and the cost and complexity of installing a ventilation system are significant factors to be weighed in planning window replacement. Comfort. Window brynmawr replacement at McLean Gardens would result in reduced window air leakage and increased wintertime temperatures at the inner glass surface. Reduced air leakage means fewer drafts near windows. Increased wintertime glass temperature would reduce cold convection currents that spill off windows, further reducing the sensation of drafts. The temperature increase would also increase the average radiant temperature of the indoor environment. (Average radiant temperature has nearly as strong an influence on comfort as does air temperature.) replacement While all the replacement options would yield windows some increase in temperature, the higher-performance low-e, argon-filled glass would offer the greatest increase. While improved comfort has value in itself, it may also result in thermostat adjustments that yield additional real energy savings. 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 brynmawr responded to our request for a waiver to access utility records, and we checked our simulation results for the existing-windows case against these bills, tweaking some of our assumptions as a result. We also did some basic sensitivity runs to evaluate the effect of orientation and shading.The results brought some surprises (see replacement Figure 3 for typical results for one apartment type). The first is the large projected heating savings for the storms-only replacement, windows an option with a far lower cost than full window replacement. This results from the combined effects of reduced infiltration and the estimated reduction in U-value attributable to a tighter system.
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