The Home Energy Rating System (HERS) Program addresses problems in insulation, installation, and poor quality equipment installation for heating, ventilation, and air-conditioning (HVAC) systems. Studies have shown that the heating and air-conditioning ducts in the average home leak 30 percent of the conditioned air in the system. Incorrectly installed insulation does not provide the resistance to heat flow listed on the label.
The Energy Commission requires licensed contractors to seal and test the ducts of a home when an HVAC system is installed or replaced. After the licensed contractor seals the ducts, a HERS rater will verify the leakage amount of the duct system.
HERS Booklet: What Is Your Home Energy Rating? - This booklet provides whole-house rating information.