All About HERS Testing and HERS Rating

All About HERS Testing and HERS Rating

What is HERS testing?
HERS Testing, also known as a Home Energy Rating System test, originated from the HERS program which was created to measure the efficiency of whole house energy components.

Who needs HERS Testing?
The California Energy Commission mandates that newly constructed residential and non-residential buildings have HERS testing to comply with local permits. HERS testing also applies to existing buildings such as installation of a new home HVAC system. HERS can be triggered by a new furnace, new or altered duct system, new AC condenser or refrigerant containing component, new ductless or ducted mini split system.

Why HERS Testing?
The purpose of HERS Testing is to ascertain the energy performance of a building and verify that it complies with current regulations. These tests examine the energy efficiency of the heater, AC condenser, air ducts, duct insulation, HVAC damper, and more. HERS Testing also ensures optimal air quality for the comfort, health and safety of the people who occupy that space, plus indicates opportunities to help reduce energy costs.

How is a HERS Rating Determined?
An air conditioning and heating contractor, general contractor, builder or homeowner enlists a certified HERS rater, like Rapid Duct Testing, to render several diagnostic tests, known as HERS testing. Once these tests are completed the technician will be able to determine a HERS report with the data collected.

The primary tests that comprise HERS Testing, include the blower door test (whole house test) and duct leakage test (duct blaster test).

The WHOLE HOUSE test involves a high-powered fan, called a blower door, that draws air from inside the house to the outside or vice versa. This creates a pressure differential between the home and the outside which determines air leakage. Acceptable air leakage will then be determined by the size of the home or the equipment.

Performing a smoke test for duct leakage enhances this process. Should excess leakage be discovered, corrections to the air duct sealing will be required and the process of pumping smoke (theatrical fog) into the duct system will allow the contractor to identify leakage. Additional tests that may be performed include an EER/SEER verification, fan efficacy test (fan watt draw), minimum air flow measurement, refrigerant charge verification test, etc. With each test that passes, a corresponding form is issued.

Due to the different allowances for new buildings versus HVAC modifications or replacements in older buildings, it is vital to find a HERS rater that stays up-to-date on current regulations