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#1 WALL/ ATTIC INSULATION: Adequate insulation is among the most important
considerations for energy conservation with heating and cooling. The effectiveness
of insulation is determined by the “R” value meaning resistance to passage of heat. If it is unfeasible to replace all insulation, targeted areas with the greatest savings potential can be determined via a thermal infrared energy audit. In particular double check the roof and exterior walls are sufficiently insulated in order to prevent unnecessary heat escape. There are several types of insulation to choose from some of which are easier for the occupants to install. Fiberglass batts or foam board are easiest for residents to use, but only work in exposed wall or attic cavities. Spray foam and blown-in cellulose insulation is slightly more difficult to install, and is often used by insulation contractors, but it does provide access to enclosed wall and attic cavities. Some additional ways to improve insulation:
- Exterior wall outlets and light-switches, which are often holes in existing insulation, can be insulated with outlet and light-switch gaskets.
- If a home sits on rafters or blocks, having a non-insulated space below wastes energy. Insulated concrete forms or spray foam can sometimes be used on the exterior of these below-house areas. Blown-in cellulose or spray foam can also sometimes be added to interior floor cavities.
#2 ADDING INSULATION TO WINDOWS: Heat conductivity in windows is usually
measured in U-value, which is the inverse of R-values – window manufacturers often argue that this is an entirely different measure, which it is not. Converted into R, the worst performing windows usually provide 0.5R, while the most advanced high-tech / low-conductivity windows provide around 3R, as compared to R-19 or R-44 in well-insulated walls or attics. Due to this reason, windows are not the best place to attempt to improve insulation (though you should definitely make sure that all cracks are well sealed). However, you can improve insulation to windows in a number of ways:
- Replacing single pane windows with Energy Star models is expensive but does reduce heating and cooling costs marginally. It is higher priority to replace windows when cracks and breaks compromise their functionality or make it too hard to properly seal your windows. If the frame and sash of the old windows are rotting or dysfunctional it is all the more reason for an upgrade if not a total replacement.
- Assuming you have sealed all air leaks, the next step is using clear plastic window film cover. It achieves about the same energy savings as replacing your windows but for a tiny fraction of the cost. Putting clear plastic wrap tightly stretched and sealed over the windows will provide some translucent insulation that still allows natural light can be used for the winter months.
- You can also use thermal curtains or insulated draperies to reduce heat loss through your windows at a lower cost.