Improving Home Energy Efficiency by Sealing and Insulating

Studies continue to show that sealing and insulating one’s home in the outer walls, ceilings, windows, doors, and floors is among the most cost-effective ways to improve energy efficiency and provide comfort. Residential customers can often expect to save 20 percent on their heating and cooling costs (i.e. 10 percent of their total annual energy bill) by sealing air leaks throughout the home to stop drafts, improving insulation will prevent heat loss in the winter and cooling loss in the summer, and selecting energy efficient windows,

Locate and Measure Air Leaks

Air leaks and drafts can often be easily identified through feel, particularly around doors and windows. Depending on accessibility, holes in attics, basements, and crawlspaces can pose challenges to locating and subsequently addressing leaks. Residential customers should consider hiring a contractor who can offer rigor and precision via the use of diagnostic tools and processes to ensure the greatest impact when applying caulk, spray foam, or weather stripping to identified leaks. Some of the specialized diagnostic tools include

• Blower Door: Using a variable speed fan mounted in a door frame, a blower door measures air leakage by pressurizing and depressurizing a house.
• Duct Blower: Used to measure duct air leakage.
• Manometer: Measures the difference in pressure between 2 locations.
• Flow Hood: Measures air flow through a register.
• Infrared Camera: Identifies surface heat variations (detects heat losses and air leakage in buildings).

Air Seal Tips

In applying the various sealing techniques, there are several of factors to consider:

• Though unlikely in older homes, homeowners need to be aware of the possibility of sealing homes too tightly. Some fresh air is need in every home to ensure sound indoor air quality. Should a home be too tight, a fresh air ventilation system will be required.
• After completing a home sealing project, ensure that the combustion appliances (e.g. furnace, water heater, and dryer) are venting properly

Adding Insulation

Insulation is used to maintain warmth in the winter and coolness in the summer. It is measured by R-value which measures its ability to resist heat flow. The higher the R-value, the more its power to insulate and different R-values can be appropriate by application and location (i.e. walls, attics, basements and crawlspaces). Most significantly, insulation works most effectively when air is not moving through or around it. Consequently, the previous discussion regarding air sealing is critical to attaining the desired results of improved insulation.

For optimal results, homeowners should start with the attic where R-38 is most commonly recommended (R-49 is recommended for the coldest climates).

Sealing Air Ducts

Air ducts are used to distribute air that has been conditioned via forced-air heating or cooling systems throughout a house. Typically, 20 percent of the air moved in this manner is lost due to leaks or improperly sealed connections. This results in increased utility bills and  challenges in maintaining comfort in the home, independent of any thermostat setting. Unfortunately, many ducts are concealed in walls or between floors, presenting challenges regarding accessibility. Those that are exposed (attics, basements, crawlspaces and garages) can be addressed by sealing the leaks with a duct sealant. One might consider insulating those ducts that are more exposed to outside temperatures (attics, garages and crawlspaces), thus mitigating the impact of severe heat in the summer and extreme cold in the winter.