Fan Efficacy Verification
ECC / HERS Fan Watt Draw Testing in Northern California
Fan efficacy verification measures how efficiently an HVAC system’s air handler moves air through the duct system.
Under the California Energy Code, this is a required ECC / HERS field verification to ensure the fan is not drawing excessive power to deliver airflow.
Pacific Airflow provides certified ECC / HERS fan efficacy testing for contractors and HVAC installers across Northern California.
What Is Fan Efficacy?
Fan efficacy is measured in:
Watts per CFM (W/CFM)
It tells us how much electrical power the fan motor must use to move a given amount of air.
A system that moves air efficiently uses less wattage.
A poorly installed system forces the fan to work harder and draw more power.
This is why the Energy Code requires this test.
2025 Code Requirement
For systems requiring verification, the fan must meet:
≤ 0.45 Watts per CFM
This is stricter than older code cycles and leaves less room for poor duct design, restrictive filters, bad transitions, or undersized returns.
If the fan draws too many watts to move air, the system fails.
When Is Fan Efficacy Testing Required?
Fan efficacy verification is required when:
New HVAC systems are installed
Duct systems are installed or replaced
Systems are installed as part of new construction
A project requires ECC / HERS verification for permit closeout
This test is commonly required along with:
Duct leakage testing
Refrigerant charge verification
Airflow verification
What Causes a System to Fail?
Most failures are not equipment problems — they are installation problems:
Undersized return ducts
Excessively long duct runs
Sharp transitions and poor fittings
Dirty or restrictive filters
Poor plenum design
Kinked or compressed flex duct
Improper airflow setup
The fan is forced to work harder to overcome these restrictions, which increases watt draw.
How We Test Fan Watt Draw
We measure:
Total system airflow (CFM)
Electrical watt draw of the air handler
Static pressure in the duct system
Using calibrated equipment, we determine whether the fan is operating within the allowed watt-per-CFM limit required by code.
This test provides real data about how well the duct system and air handler were installed.
Why This Matters
Poor fan efficacy leads to:
Higher electrical usage
Reduced system lifespan
Noise issues
Poor comfort and airflow
Failed inspections and permit delays
This test ensures the system performs the way the manufacturer and energy model intended.
ECC / HERS Certified Verification
As a certified ECC Rater, Pacific Airflow performs fan efficacy verification that is:
Registered with the ECC Provider (CHEERS)
Accepted by Northern California building departments
Required for permit final and inspection approval
This is official documentation of HVAC system performance.
Serving Northern California HVAC Contractors and Builders
Pacific Airflow provides fan efficacy testing for:
Residential new construction
HVAC changeouts
Additions and alterations
Multifamily projects
We work directly with HVAC installers to diagnose issues quickly if the system is close to failing.
Schedule Your Fan Efficacy Test
If your project includes new ductwork or HVAC installation, this test may be required before final inspection.
Pacific Airflow is your local ECC / HERS testing partner for compliant fan efficacy verification across Northern California.
Contact us today to schedule your test.