12,000 sq ft Single Story
Inputs
Home2,000 sq ft
Ceiling8 ft
Stories1
Result
Required CFM5,333 CFM (30" fan)
2,000 × 8 = 16,000 cu ft / 3 min = 5,333 CFM. A 30" fan (6,000 CFM) recommended.
Be the first to rate this calculator
No ratings yet
Whole House Fan Calculator — CFM Sizing Tool
Units
Required CFM
5,333
Fan
30" Fan
Savings
$1,117/yr
Fan Sizing
Recommended Fan
30" Fan
6,000 CFM (5,333 needed)
Power
350W
Annual Cost
$35/yr
Cost & Savings
Fan Cost$500
Installation$500 – $1,500
Total$1,000 – $2,000
Fan Annual Cost$35/yr
AC Annual Cost$1,152/yr
Annual Savings$1,117/yr
Find an HVAC Technician Near You
Get free quotes from HVAC professionals near you
100% freeNo obligation2-minute match
We may earn a commission when you request quotes, at no extra cost to you.
Showing results for your area
Find an HVAC Technician Near You
Get free quotes from HVAC professionals near you
100% freeNo obligation2-minute match
We may earn a commission when you request quotes, at no extra cost to you.
Showing results for your area
What You'll Need
Quietcool QC CL-4700 RF Classic Advanced Whole House Fan with Wireless Control - Up to 4415 CFM - Two Speed - Covers up to 2,208 SQFT - 10 Year Warranty - Removable Grille
$1,109.00
View on Amazon
Quietcool QC ES-4700 RF Energy Saver Advanced Whole House Fan with Wireless Control - Up to 4195 CFM - As low as 75 watts - Two Speed - Covers up to 2,098 SQFT - 10 Year Warranty - Removable Grille
$1,349.00
View on Amazon
Quietcool QC CL-5400 RF Classic Advanced Whole House Fan with Wireless Control - Up to 5024 CFM - Two Speed - Covers up to 2,512 SQFT - 10 Year Warranty - Removable Grille
$1,209.00
View on AmazonQuietcool QC CL-4700 RF Classic Advanced Whole House Fan with Wireless Control - Up to 4415 CFM - Two Speed - Covers up to 2,208 SQFT - 10 Year Warranty - Removable Grille
$1,109.00
View on AmazonQuietcool QC ES-4700 RF Energy Saver Advanced Whole House Fan with Wireless Control - Up to 4195 CFM - As low as 75 watts - Two Speed - Covers up to 2,098 SQFT - 10 Year Warranty - Removable Grille
$1,349.00
View on AmazonQuietcool QC CL-5400 RF Classic Advanced Whole House Fan with Wireless Control - Up to 5024 CFM - Two Speed - Covers up to 2,512 SQFT - 10 Year Warranty - Removable Grille
$1,209.00
View on AmazonAs an Amazon Associate, we earn from qualifying purchases.
Price as of Jul 24, 2026. Product prices and availability are accurate as of the date indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
Related calculators
AC Size CalculatorCentral AC sizingBTU CalculatorBTU calculationAttic Ventilation CalculatorAttic vent sizingWhole House Fan Cost Calculator — 2026 QuietCool & Centric Air InstallEstimate 2026 whole house fan cost by CFM, brand, and install type. A QuietCool or Centric Air unit typically runs $1,200-$2,800 installed nationwide.Bathroom Fan CFM CalculatorCalculate the correct exhaust fan CFM for your bathroom based on room size and fixtures. Get duct sizing, sone ratings, and code-compliant ventilation.Mini Split Calculator — BTU Sizing ToolCalculate mini split BTU size by room dimensions, climate zone, and insulation. Get tonnage, SEER-based energy costs, and installation price estimates.
Example Calculations
22,500 sq ft Two Story
Inputs
Home2,500 sq ft
Ceiling9 ft
Stories2
Result
Required CFM15,000 CFM (48" fan)
2,500 × 9 × 2 = 45,000 cu ft / 3 = 15,000 CFM. A 48" fan (14,000 CFM) needed.
Frequently Asked Questions
QHow do I calculate CFM for a whole house fan?
Multiply your home volume (sq ft × ceiling height × stories) and divide by 3 for a complete air exchange every 3 minutes. A 2,000 sq ft home with 8 ft ceilings needs about 5,333 CFM.
- Formula: Home Volume (cu ft) / 3 minutes = required CFM
- 2,000 sq ft × 8 ft ceiling = 16,000 cu ft / 3 = 5,333 CFM
- Multi-story: multiply volume by number of stories
- Round up to next fan size (4500, 6000, 8000, 10000, 14000 CFM)
QHow much can a whole house fan save on AC costs?
A whole house fan uses 200–900 watts vs 3,500–5,000 watts for central AC. Annual savings range from $200–$600. The fan pays for itself in 1–3 years.
- Whole house fan: $0.01–$0.05 per hour to operate
- Central AC: $0.30–$0.60 per hour for a 3-ton system
- Best when outdoor temp drops below 80°F in evenings
- Can reduce AC usage by 50–90% in dry climates
QHow much open window area do I need?
You need 1 square foot of open window area for every 750 CFM. A 6,000 CFM fan needs at least 8 sq ft of open window area to prevent back-pressure and noise.
- 6,000 CFM fan needs 8+ sq ft of open window NFA
- Open 4–6 windows on the windward side for cross-ventilation
- Insufficient window area causes whistling noise and reduced airflow
- Screen reduces NFA by 30–50%; account for this in calculations
QHow much does a whole house fan cost to install?
A whole house fan costs $300–$1,600 for the unit plus $500–$1,500 for professional installation. Total ranges from $800–$3,100 depending on fan size and attic access.
- 24" fan (4,500 CFM): $300–$500 for homes under 1,500 sq ft
- 30" fan (6,000 CFM): $500–$800, most common residential size
- 36–42" fan (8,000–10,000 CFM): $800–$1,100 for larger homes
- Installation: $500–$1,500 including ceiling opening, wiring, and damper
Related Resources
What 800+ DIY Framing Calculations Reveal About Home Builds in 2026
Read our guide
Drywall Calculator Guide: Sheets, Mud, Tape & Cost for Any Room
Read our guide
Wall-to-Wall WiFi Coverage for a House: How Many Mesh Nodes (2026)
Read our guide
AC Size Calculator
Size a central AC
BTU Calculator
Calculate BTU needs
Ceiling Fan Size Calculator
Ceiling fan sizing
More Construction Calculators
See all construction calculators
Last Updated: Jul 24, 2026
This calculator is provided for informational and educational purposes only. Results are estimates and should not be considered professional financial, medical, legal, or other advice. Always consult a qualified professional before making important decisions. UseCalcPro is not responsible for any actions taken based on calculator results.