Kostenloser Ablüfter-Rechner

Berechnen Sie den CFM-Bedarf für Ablüfter in Bad, Küche und Hauswirtschaftsraum.

ft
ft
ft
ACH

Fan Rating Needed

85 CFM

Raumvolumen640 cu ft
CFM per Sq Ft Rule80 CFM

Fan Rating Needed vs Room Length

Formel

## Exhaust Fan Sizing **CFM = Room Volume x ACH / 60** The HVI (Home Ventilating Institute) recommends a simpler rule for bathrooms: 1 CFM per square foot for rooms up to 100 sq ft, and 50 CFM minimum. For larger bathrooms, add 50 CFM per fixture (toilet, shower, tub). Kitchens need 100-400 CFM depending on cooking.

Lösungsbeispiel

10 x 8 ft bathroom, 8 ft ceiling, 8 ACH.

  1. 01Volume = 10 x 8 x 8 = 640 cu ft
  2. 02CFM = 640 x 8 / 60 = 85 CFM
  3. 03Square foot rule = 80 CFM
  4. 04Use at least an 80-90 CFM fan.

Häufig Gestellte Fragen

What sone rating is quiet?

Under 1.0 sone is considered very quiet (leaves rustling). 1-2 sones is quiet operation. Above 3 sones is noticeable. Look for fans rated under 1.5 sones for bathrooms.

Does duct length affect fan performance?

Yes. Longer duct runs and more elbows create back-pressure that reduces actual airflow. Check the fan performance curve at your estimated static pressure, typically 0.1 to 0.25 inches of water.

Lernen

How to Calculate Concrete Needed for Any Project

Verwandte Rechner