What is HERS?

HERs stands for Home Energy Rating Service. Title 24 of the California Building code was established by the California Energy Commission (CEC) in 2005 with goals for reducing energy in residential homes. All newly installed Furnace/AC (HVAC) units must be certified by a third partner HERS Rater. This has been a requirement in the hotter climate zones of California since 2005 and as of July 1, 2014 any system installed in ALL climate zones must be Certified for Duct Leakage. CalCERTS has been given the responsibility for running the program by the CEC.

It has been determined by the CEC that the average home has duct leakage of 30%. This means that you are spending extra money to heat and cool your attic or under house crawl space.

HERS rating typically consists of four measurements:

• First is duct leakage, any new home be leak less than 6%, existing homes must leak less than 15% of air flow.  The HVAC installer must seal all accessible leaks in the plenum and ducts as part of the new system installation process. The  duct leakage test the HERS Rater performs is done by first sealing all the registers in the home and then pressurizing the system through the return (intake) vent and testing for leakage. If the system fails all accessible leaks must be repaired and the system retested. 
• The second test is the refrigerant charge verification test. The HERS rater will verify the pressure of refrigerant is properly charged by the installer.
• The third test the rater performs is the air flow volume of air flowing over the cooling coil. This test is performed by using a flow hood which measures air flow. The flow must exceed 350cfm of air per ton of air conditioning.
  
• The fourth test is fan watt draw. The test is to verify the total energy consumed by the fan set at its highest speed. The fan must draw less than 0.58 watts/cfm of air.

The Process

The typical process is the HVAC installer obtains a permit from the local city and creates the CF-1R form. After the installer installs the new system they test the duct leakage and air flow and fill out the CF-2R form. Then the HERS Rater is called and he uses the CF-1R form which determines the requirements of the testing. The HERS rater works for the homeowner but may be contracted by the HVAC installer to perform the rating as part of a total installation service for the homeowner.