Frequently asked Questions
FAQ for Existing Homes
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What is a HERS rater?
HERS is an acronym for Home Energy Rating System rater. This is a certified third party special inspector who does “field verification and diagnostic testing” for compliance of Title 24 energy measures.
What is an energy measure?
The California Energy Commission has certain testing requirements on energy measures. Energy measures, commonly on an existing home, may include duct testing, refrigerant charge measurement, cooling coil airflow measurement and fan watt draw measurement.
How do I know if I need to have a test done?
Normally, your contractor will let you know. Some unscrupulous contractors try to convince a homeowner not to “pull” a permit in order to avoid any testing and avoid a third party inspector verifying that the contractor has done their job well or properly. If that is the case, find another contractor. The installation of any part of a central heating or cooling system will “trigger” required testing.
What kind of test do I need?
It depends on where you live. You may not need any testing in coastal zones in California but the central valley and sierra region will require some type of testing. If you know your zip code, you can look up your “climate zone” from this list.
If you live in climate zone 2, and 9 through 16, and you have replaced a furnace, air handler, heating or cooling coil, outside condenser, or furnace heat exchanger, you will need to have a duct test completed by a HERS rater.
If you live in climate zone 2, and 8 through 15, and you have replaced a furnace, air handler, heating or cooling coil, outside condenser, or furnace heat exchanger, you will need to have a refrigerant charge and airflow measurement completed by a HERS rater.
If you live in climate zone 2, and 9 through 16, and you have added or replaced over 40’ of ductwork (in unconditioned space), you will need to have a duct test completed by a HERS rater.
If you live in climate zone 10 through 15, and you have replaced all your split system heating and cooling equipment and all your ductwork, in addition to the above testing, you will need to have a cooling coil airflow and fan watt draw measurement completed by a HERS rater.
Are there any exceptions to having my house tested?
Yes. There are three.
- If your duct system is sealed or insulated with asbestos you do not need a duct test. If you have a split system air conditioner, you still need to have a refrigeration charge and airflow measurement.
- If your duct system has less than 40’ of ductwork in unconditioned space you do not need a duct test. If you have a split system air conditioner, you still need to have a refrigeration charge and airflow measurement.
- If your duct system has previously been tested and certified by a HERS rater you do not need a duct test unless you have added or replaced over 40’ of ductwork in unconditioned space since the previous HERS testing. If you have a split system air conditioner, you still need to have a refrigeration charge and airflow measurement.
My contractor told me he can do the testing. Is that true?
Contractors who do their own testing can place your home into a sample group and that is fine. A HERS rater will select one home from that sample group for testing. If you want your home tested and not be part of a sample group, that is your right but it may cost you more money.
Who is supposed to pay for this testing?
Since this testing is for the benefit of the homeowner, you actually hire the HERS rater and it is your financial responsibility to pay for this service. Many contractors include the testing fees in their contracts and pay the HERS rater directly for you, so look closely at your contract or ask your contractor who will be responsible for payment to the HERS rater. Pricing varies depending on how many tests are required and how many trips to the house would be required. Typical pricing is $275 to $350 per trip but there are some exceptions. Feel free to call for your specific situation.
What is the benefit to me? It just sounds like more money out of my pocket!
I love this question. Before October 2005, contractors did not seal the leaks in the existing ductwork because they didn’t have to. Studies showed the average duct system leaks 30% of the airflow of the system. That means you are receiving only 70% of your heating or cooling air into your home. That’s big money out of your pocket. Since October 2005, the California Energy Commission requires contractors to cut that loss in half. Contractors now have to keep the duct leakage under 15% of the total airflow. Many contractors I have dealt with have been able to reduce duct leakage below 10%. That is huge money savings. If the contractor replaces all your ductwork, they have to keep the leakage below 6%. Also, studies have shown that two thirds of all split system air conditioners do not have the right amount of “freon” or refrigerant charge in the system. That means you will use a lot more energy to operate your air conditioner and improper charge can absolutely affect the lifespan of your air conditioner. To be sure, the Energy Commission wants a third party special inspector to confirm and certify the contractor has actually completed their task(s).
What if the contractor can’t get it under 15% leakage?
If your home has an existing building cavity or platform that is conveying airflow which is not ducted, the contractor must seal all accessible leaks in the duct system using a theatrical fog test to confirm the leaks are sealed and have a HERS rater certify the results. This option cannot be put in a sample group.
I have some additional questions. Should I email you or can I call you?
Either way is good for me. I can’t answer every possible question here. I want you to be confident about the process and results. If you email me at Rater@HVACrater.com please include your phone number in case your question requires more than a quick response. My phone number is 925-864-5668. I appreciate the opportunity to help. This is a confusing process and saving energy and money is the ultimate goal.