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What is HERS?

HERS stands for Home Energy Rating System

The goal of the program is to provide reliable information to differentiate the energy efficiency levels among California homes and to guide investment in cost-effective home energy efficiency measures.

The Energy Commission has a process for certifying Home Energy Rating System (HERS) raters who perform third-party inspections when verification of duct sealing, thermostatic expansion valves (TXVs), refrigerant charge, airflow measurement, and building envelope sealing measures are used when complying with the 2005 Standards. Testing and verification exists in both Residential and Nonresidential situations

Beginning October 1, 2005, you must have your home's ducts tested for leaks when you have a central air conditioner or furnace installed or replaced. Ducts that leak 15 percent or more must be repaired to reduce the leaks. After your contractor tests and fixes the ducts, you choose whether to have an approved third-party field verifier check to make sure the duct testing and sealing was done properly or to have your house included in a random sample where one in seven duct systems are checked.

Duct sealing is not required in the following situations:

when homes are in specific coastal climates.
when systems have less than 40 feet of ductwork in unconditioned spaces like attics, garages, crawlspaces, basements or outside the building.
when ducts are constructed, insulated or sealed with asbestos.

There also are specific alternatives that allow high efficiency equipment and added duct insulation to be installed instead of fixing duct leaks.

You also should know that any contractor failing to obtain a required building permit and failing to test and repair your ducts is violating the law and exposing you to additional costs and liability. Real estate law requires you to disclose to potential buyers and appraisers whether or not you obtained required permits for work done on your house. If you do not obtain a permit, you may be required to bring your home into compliance with code requirements for that work and you may have to pay penalty permit fees and fines prior to selling your home.

The greatest energy use in California homes is for central air conditioning and heating. Most homes with central air conditioning and heating systems have ducts that were never properly sealed. The average home's ducts leak around 30 percent of the conditioned air outside the home. These leaks are taking money straight out of your pocketbook. Properly sealed ducts will lower your energy bills, reduce pollution inside your home, and help to avoid a repeat of the inconvenience and health and safety risks that we suffered during the power blackouts in 2000.