Insulation materials reduce the transfer of heat from one place to another. In Maine homes, insulation reduces the flow of heat from the interior to the exterior in the winter, and in the summer months, from the exterior to the interior. For optimal energy efficiency, your home should be insulated from the roof down to the foundation. When insulation is properly installed, heating systems run less frequently, helping to reduce on-going energy expenses while meeting home heating needs.
Insulation’s ability to reduce heat transfer is rated in terms of its resistance, or R-value. You’ll often see information about insulation conveyed in total R-value. As an example, the Department of Energy recommends that attics in Maine be insulated to R49 or approximately 16 inches deep in a typical attic. The average Maine home is well below that and has an attic insulation level of R13 (e.g. – 3.5 inch fiberglass batt insulation). Efficiency Maine recommends that the entire building envelope be insulated from top to bottom including attics, cathedral ceilings, all wall cavities, rim joists, basement walls, and crawl spaces.
Insulation’s effectiveness depends on material used, how much of it is installed, where it is installed, and if the home has been effectively air sealed. For example, fluffy insulation works great where there is no air flow but does little if the area is drafty or unsealed. Gaps or settled insulation leave spaces for cold air and moisture to flow, while insulation properly installed leaves none of these gaps. There are a number of insulation materials available that range from recycled fiber materials to foam boards to wool.
During a home energy assessment, an energy auditor or insulation contractor will be able to recommend appropriate insulation levels and tell you which insulation materials might work best in certain locations. For example, cellulose insulation is a popular and relatively inexpensive choice for attic insulation. Many homeowners choose rigid foam or spray foam insulation for rim joists and basement walls. Insulating basement walls to at least two feet below grade is highly cost effective. Consulting with an energy advisor is the best way to determine what insulation materials will work best in your home as well as discuss indoor moisture or other health and safety concerns.
- Lower Heating and Cooling Costs – Effective insulation means that it takes less heat to make your home comfortable and will reduce heating demand no matter what fuel you use to heat your home.
- Increased Year-Round Comfort – Insulation projects typically make rooms warmer in the winter and cooler in the summer.
- Reduced Outside Noise – Increased insulation levels may also reduce outside noise making your home quieter.