Bathroom Fan Calculator

The bath fan calculator is standard guide to help you find the minimum fan rating for your specific bathroom.
Bathroom fan calculator. To determine the square footage of your bathroom multiply the length times the width. The cfm represents the airflow required to completely exchange the air in your bathroom 8 times in one hour. The rule of thumb is that you need at least 1 cfm per square foot of room area.
Actual costs will depend on job size conditions and options. That s why we developed this handy bathroom vent fan cfm calculator. Simply enter the dimensions of your bathroom in the calculator below to determine the minimum size vent fan you need for the bathroom in your home.
For a second fan selector based only on the building regulations and excludes air change rates click here. For example if your bathroom is 80 square feet you ll need an 80 cfm fan such as the broan smartsense 80 cfm ventilation fan available from supplyhouse. Building regulations part f 1995 england wales.
It is based on hvi home ventilating institute guidelines that recommend approximately 8 room air exchanges per hour for a bathroom under 100 square feet of area. Minimum size fan allowed extract table 1 to see official ventilation regulations. Determine the required cfm for your bathroom fan.
An effective bathroom fan should be capable of replacing the entire volume of air 8 times per hour or every 7 5 minutes. Bathroom 15 litres second. For a basic project in zip code 47474 with 1 fan the cost to install a bathroom fan starts at 216 626 per fan.
Whether exhausting air or bringing fresh air into a structure the calculation produced should help to figure out the size of fan s required to accomplish the air exchanges needed. To arrive at your required cfm simply divide your bathroom s volume by 7 5. Divide the volume of your bathroom in feet by 7 5.
Standard fan sizing applies to bathrooms that are 100 square feet or less. The result is the cfm or cubic feet per minute rating required for your bathroom fan. This fan calculator is typically used to calculate the cfm or cubic feet per minute of air exchange that may be desired in a building.
Kitchen 60 litres second. Bathroom vent cfm calculator uses 3 stage formula located below. The higher the bath fan rating the more air can be vented out of the bathroom which means less moisture and mold build up.