Under the 2016 Energy Standards, newly constructed residential buildings have mandatory and prescriptive HERS measures. These measures include duct leakage, ventilation airflow, indoor air quality, fan efficacy, and depending on the climate zone, refrigerant charge verification (Non-residential standards include duct leakage testing, insulation of hot water pipes and HVAC efficiency verification). If your Title 24 Energy documentation calls out any of the mentioned HERS requirements, a certified third party HERS Rater will need to conduct verification testing to confirm that the systems have been installed properly and meet code compliance.

There are conditions that can be verified prior to HERS testing that will help the process run efficiently, mitigate any possible failures, and avoid delays in Certificate of Occupancy. Below are 5 things to keep in mind when scheduling a HERS Rater:

  1. Permanent power – The HERS Rater will need power to operate the testing equipment and turn on the HVAC systems. It is highly preferable to test using permanent power rather than temporary power. Temporary power runs the risk of voiding the warranty of the HVAC systems and may not reflect accurate results for the performance of the systems.
  2. Thermostats installed – To properly verify the ventilation airflow and indoor air quality measures, the HERS Rater will need to turn on the HVAC system using the thermostats.
  3. Ensure all possible sources of duct leakage are sealed – This includes grilles secured to the ducts and register boxes sealed to the drywall. Often overlooked are the FAU door frames. If the door frames are not sealed to the drywall, a portion of the return air will be drawn in from the FAU location into other parts of the building. Depending on the FAU location (e.g. if it is located in the bathroom), this is not only a duct leakage concern, but could also become an indoor air quality issue down the line.
  4. Mechanical startups completed prior to testing– HERS Testing is the verification of the installing contractor’s work. Mechanical startups will ensure that all systems are operating properly and any issues are resolved prior to HERS Testing. In general, this is a great contributing factor in preventing possible HERS Testing failures and will help speed up the testing process.
  5. Gas meters and heating system operational during colder months – This is specifically needed if your Title 24 calls for refrigerant charge verification. To take proper readings, the HERS Rater will need to be able to raise the indoor temperature to at least 70˚F. If the heating system is not operational on the day of HERS Testing, the rater might need to return to the site at a later date to complete testing, risking the possibility of a delay in C of O. For HERS Testing during warmer months, this won’t be necessary at the time of testing.

VCA Green possesses a highly qualified team of HERS Raters to perform these tests. For energy consultation services such as this, please contact Moe Fakih below.


Moe Fakih, Principal
714-363-4700 x501

Contributing Writer: Yvonne Lo