Calculate the proper exhaust fan size for your bathroom with our professional CFM calculator. Ensure optimal ventilation for homes in Fairfax County, Arlington, Alexandria, DC, Montgomery County, and Prince George's County.
Use our professional calculator to determine the proper CFM (cubic feet per minute) rating for your bathroom exhaust fan.
Understanding the industry standards and best practices for bathroom ventilation sizing.
1 CFM per square foot of bathroom space, with a minimum of 50 CFM for any bathroom.
For bathrooms over 100 sq ft, calculate CFM based on individual fixtures.
Optimal ventilation provides 8-10 air changes per hour for effective moisture removal.
Choose fans with appropriate sone ratings for comfortable operation.
Proper ductwork design is critical for achieving rated CFM performance.
Virginia building codes require mechanical ventilation in windowless bathrooms.
Important factors that affect exhaust fan performance and installation requirements.
Ceilings over 8 feet require additional CFM to handle increased air volume.
Separate shower and tub, multiple sinks, or jetted tubs increase moisture production.
Inadequate insulation allows more condensation on cold surfaces.
Extensive ductwork reduces effective CFM, requiring higher-rated fans.
May require wall-mounted fans or creative ductwork routing through walls.
Joists, HVAC ducts, or plumbing may limit fan placement options.
New circuits may be needed for fans with lights, heaters, or high CFM ratings.
Proper exterior termination prevents moisture infiltration and backdrafts.
Our licensed electricians provide expert ventilation design and installation throughout Fairfax County, Arlington, Alexandria, DC, Montgomery County, and Prince George's County.