Bathroom Fan Calculator

This page is designed to be a general guide for selecting an exhaust fan based on the size of the room and the type of application the fan will be used for.

Bathroom fan 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. The cfm represents the airflow required to completely exchange the air in your bathroom 8 times in one hour. Minimum size fan allowed extract table 1 to see official ventilation regulations. All you need to do is select the application from the dropdown enter the size of the room and we will provide you with a general capacity range m3 hr that you should be looking to achieve from the extraction fan.

A bathroom fan is an essential piece of hardware in any indoor bathroom without a window. 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. This tool may be used to comply with the requirements of 2015 irc section m1506 2 and 2018 irc section m1504 2. 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.

This keeps the moisture from the. When installing a vent fan make sure there s at least a 1 2 gap under the bathroom door to allow fresh air to enter the room when the fan is running. Other options for bath fans include lights heaters and even humidity sensors. The fan pulls air out of the bathroom and allows fresh air to be drawn in.

The bath fan calculator is standard guide to help you find the minimum fan rating for your specific bathroom. 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. The result is the cfm or cubic feet per minute rating required for your bathroom fan.

Bathroom 15 litres second. The higher the bath fan rating the more air can be vented out of the bathroom which means less moisture and mold build up. For a second fan selector based only on the building regulations and excludes air change rates click here. It removes hot moist air and it can remove odors.

How to calculate cfm for bathroom fan. Divide the volume of your bathroom in feet by 7 5.