The best whole house fan is the one sized for your home and your attic, quiet enough to sleep with, and efficient enough to run every night. Here is what to compare on any spec sheet.
The best whole house fan for you comes down to nine specs: tested airflow sized to your home, CFM per watt, noise in dBA, damper insulation, required attic vent area, the ceiling opening and joist fit, warranty, controls and installation support. CentricAir lists the home size each model is built for, so sizing starts with your square footage.
Spec sheets for whole house fans list a lot of numbers. A handful of them decide whether you will be happy with the fan in August. This checklist works for any brand, and we show where each CentricAir model lands.
1. Is the airflow tested and sized to your home?
Match the fan to your home size, and look for a tested rating.
CentricAir’s sizing guide lists the home size each model is built for, for one story and two story homes. For a tested rating, California’s energy code only accepts fans listed in the Home Ventilating Institute Certified Products Directory for new homes that need one. CentricAir lists the California Title 24 airflow for each model. Our sizing calculator matches your home to a model.
2. How much air does it move per watt?
CFM per watt tells you how efficiently a fan turns electricity into airflow.
Divide rated airflow by watts. The CentricAir 2.7 lists 9.41 CFM per watt and the 3.4 lists 8.49. Check low speed watts too: that is where ECM motors pull ahead.
3. How loud is it?
Look for a dBA rating on high and low.
CentricAir lists its fans at 47 to 49 dBA on high and 45 to 47 on low. The World Health Organization puts a library at about 40 dB and conversation at about 60. See our noise guide.
4. How well does the damper seal?
The damper closes the ceiling when the fan is off, so its insulation matters all year.
CentricAir fans come with an R5 backdraft damper, with a motorized R13 cold weather damper as an upgrade. In cold climates, the higher R value helps. Our winter guide explains when it is worth it.
5. Can your attic vent it?
Every fan needs attic vent area, about 1 square foot per 750 CFM.
That is Building America’s guideline, and California’s code uses the same ratio. CentricAir lists the required net free vent area on every model page, from 1.75 square feet for the 1.5 to 5.5 for the 4.0 ECM. If your attic is short on vents, plan to add them or choose a smaller fan.
6. Will it fit between your joists?
A fan that fits standard joist spacing avoids framing work.
CentricAir models fit between joists 16 inches on center, and the 4.0 models also fit 24 inch spacing. Rough openings run from 14 by 14 inches to 14 by 28 inches.
7. What does the warranty cover?
Read both the motor term and the parts term.
CentricAir fans carry a 15 year limited fan motor warranty, with other components and electrical parts covered for 3 years. QA-Deluxe fans carry a 10 year limited fan motor warranty, with other parts covered for 3 years.
8. What controls come with it?
A timer is the minimum. Temperature control is better.
See our controls guide for every CentricAir option, from the included remote with timer to WiFi.
9. How hard is it to install?
Look for clear instructions and a design that avoids framing.
CentricAir says a typical installation takes about 90 minutes. Our installation guide walks through every step.
| CentricAir model | Airflow | Watts | Noise (high) | Attic vent | Price |
|---|---|---|---|---|---|
| 1.5 | 1,263 | 143 | 47 dBA | 1.75 sq ft | $849 |
| 2.0 | 1,918 | 207 | 48 dBA | 2.5 sq ft | $1,049 |
| 2.7 | 2,709 | 288 | 49 dBA | 3.25 sq ft | $1,249 |
| 3.4 | 3,242 | 382 | 49 dBA | 4.0 sq ft | $1,449 |
| 4.0 | 3,921 | 623 | 49 dBA | 5.25 sq ft | $1,649 |
| 4.0 ECM | 4,146 | 749 | 49 dBA | 5.5 sq ft | $1,949 |
From CentricAir product pages, September 2026. CentricAir 4.0 and 4.0 ECM figures confirmed by Comfort Cool, October 2026. Prices are the sale prices listed in September 2026 (regular prices are higher), before installation, and may change.
Enter your square footage and get a matching model.
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Frequently asked questions
What should I look for in a whole house fan?
Rated airflow sized to your home, CFM per watt, noise in dBA, damper insulation, required attic vent area, the ceiling opening size, warranty and controls.
How do I know a whole house fan’s airflow rating is accurate?
Look for a tested rating. California’s energy code accepts only fans listed in the Home Ventilating Institute Certified Products Directory for new homes that need one. CentricAir lists the California Title 24 airflow for each model.
What size whole house fan do I need?
Start with CentricAir’s sizing guide, which lists the home size each model is built for, from a single room to two story homes up to 4,400 square feet. Then check that your attic has 1 square foot of net free vent area per 750 CFM.
Is a bigger whole house fan always better?
No. A bigger fan needs more attic vent area, about 1 square foot per 750 CFM, and more open windows. If your attic cannot vent it, a smaller fan may move more air in practice.
Keep reading
Sources
- U.S. Department of Energy, Building America Solution Center (PNNL), Whole-House Fans, updated Sept. 29, 2022.
- California Energy Commission, 2025 CF1R-NCB-01-E Prescriptive Newly Constructed Building form, and 2022 Energy Code Section 150.1(c)12, Whole House Fans (Energy Code Ace).
- CentricAir 1.5, 2.0, 2.7, 3.4, 4.0 and 4.0 ECM product pages (specifications tab), centricair.com, accessed Sept. 30, 2026.
- QA-Deluxe 3300 (PSC), 4800 (ECM), 5500 (PSC) and 6500 (PSC) product pages, accessed Sept. 2026.
- CentricAir Insulated R5 Gravity Backdraft Damper and Cold Climate Damper product pages, accessed Sept. 2026.
- World Health Organization, Deafness and hearing loss: Safe listening, March 6, 2026.