In homes with central heat and air, ducts are used to distribute conditioned air throughout the house. Both new and old homes typically lose 30 to 40 percent of the air that moves through the duct system due to leaks, holes, and poorly connected ducts. The result is higher utility bills and difficulty keeping the house comfortable, no matter how the thermostat is set. A duct system that is properly sealed can lower your utility bill and make your home more comfortable, energy efficient, and safer.
Air infiltration is the passage of air through cracks and gaps in the shell of a building. Infiltration increases heating and cooling costs and reduces the comfort level of occupants. Loose fitting windows and doors, cracks between the house and the foundation, and gaps around plumbing and electrical penetrations are typical sources of leaks. Reducing air infiltration is often the first action item of a weatherization plan. Reducing air infiltration is a simple improvement that we provide at no cost.
Common places we check for air infiltration include:
- Electrical outlets, switches, and ceiling fixtures
- Operable features of windows and doors
- Window and door frames where they meet the wall
- Fireplace dampers
- Chimney flashing and flues
- Attic hatches
- Wall or window-mounted air conditioners
- Plumbing, electrical, cable, and telephone penetrations
- Ducts in unconditioned spaces (though conductive heat loss is generally more significant in this situation).
Your attic plays a primary role in your homes energy efficiency. If your home is always hot or cold, then the furnace will run constantly; shortening the heating and cooling system life span and costing you thousands in energy bills and early replacement cost. The shell of your home is the barrier that prevents the temperatures of the inside and outside air from equalizing. Insulation reduces the exchange of heat through the ceiling. Adding attic insulation creates a thermal envelope which holds the temperature inside and keeps your home comfortable and efficient year round.
Your insulation level is specified by R-Value. R-Value is a measure of insulation's ability to resist heat flow. The higher the R-Value, the better the thermal performance of the insulation. The Department of Energy recommends R-30 or about 10 to 14 inches, depending on insulation type. If your attic is not insulated to R-30, 20 to 30 percent of your heating and cooling costs may go through the ceiling.
View the image below and observe the typical areas of energy loss.