Articles from September 2018

Watch out for misleading air flow claims

In 2017 the California Energy Commission set a new requirement for whole house fan makers to more accurately report their fan performance. The commission requires that each fan maker test their fans to the Appliance Efficiency Standards HVI-916 Test Method. All of the suppliers are complying with that rule. But one, QuietCool, has devised a way to get around the rule in a clever way. QuietCool created a new set of models for 2018 with model numbers like ES-6000 and ES-7000 and they now present the performances using a reference to a standard that has nothing to do with performance testing.

QuietCool has this performance data on the web page “

“QC-ES-7000 Airflow* Hi: 6878 CFM  HVI-916 Airflow (CA Title 24)** 5170 CFM
*Listed airflow specs are tested via a device that is calibrated to NIST standards.
**Recommended SQFT Coverage @ 2 CFM per SQ FT”

To the company’s credit, it has the specification for HVI-916 air flow on the line after the inflated air flow.

NIST standards do not require the same test as HVI-916 so the air flow stated is higher than what you really get in your home. What is IMPORTANT here is that both the model number (7000) and the higher air flow (6878) are misleading. The true air flow when installed in your home is the HVI-916 air flow (5170) – far lower than what they imply by their model number. Notice that the ** comment is an error – it has nothing to do with air flow.


Good news – a survey of all the other sources listed by me on this web site shows that they all are now showing true HVI-916 compliant air flow specifications. Here is the latest 2018 list in order of performance to HVI-916:

Thorwaldson    6320 CFM
VentCool          6123 CFM
Airscape           5350 CFM
QuietCool        5300 CFM