The Thermal Envelope
The buildings’ themal envelope includes the roof, foundation and walls. Together they maintain air sealing, moisture control and ventilation in the home. Sealing and insulating the roof, walls, windows, doors and floors of a home is the most cost effective way to improve energy efficiency. Good air sealing alone can reduce energy costs of running a home by as much as 50 percent.
Inside the home you have a network of ducts which transport the cool and warmed air. Proper duct sealing is essential to ensure the air is flowing out of the registers and into the home and not escaping into the walls. When any part of that ductwork or the air handler itself is outside of the building envelope a duct leakage test is required.
Ventilation of a home is very important to remove moisture and prevent mold. Attic fans, kitchen fans and bathroom fans are effective at doing that during the winter months when natural ventilation does not occur through the opening of windows. Many people think bathroom fans are for removing odor but they are actually there to remove moisture.
When building a home insulation is one place you don’t want to skimp on. Over the long run savings will be tremendous in energy costs and the home comfort will be improved. Each residential unit in Philadelphia is required to have the building envelope tested by conducting a blower door test which will check the air lekage of a home.