How to determine bathroom exhaust fan size

Use our handy online calculator to see what size bathroom vent fan you need for your home. Tam asks, What size exhaust fan should we use in our small bathroom ? Or use our online bathroom vent fan calculator. Having the right size for your bathroom is very important!

Bathrooms with higher ceilings and larger dimensions require more powerful fans to keep moisture and humidity at appropriate levels.

Standard fan sizing applies to bathrooms that are 1square feet or less.

Bathroom exhaust fans , or extractor fans, come in variety .

To determine the square footage of your . First you need to measure the size of your bathroom. To use our fan selection tool (located in the search area to the right of every page) this measurement needs to be in metres. SHOP ALL BATHROOM EXHAUST FANS . Air movement is typically measured in cubic feet per minute ( CFM ). Ventilation rates based upon eight air changes per hour are generally suggested.

For most bathrooms this works out to one CFM per square foot of bathroom area. As the trend to larger spa-like bathrooms continues to gain in popularity, the need for proper ventilation becomes more important.

The following table does lots of the math for you. The first step in determining what size exhaust fan is neede is to calculate the volume of the room. The usual rule of thumb is to equate square footage to CFM.

Panasonic with recessed light is . The formula for optimum bathroom ventilation, measured in cubic feet of air moved per minute, is.

To apply this to your bathroom , multiply the width by the length by the height to determine the total cubic feet. A properly installed bathroom fan provides ventilation , drawing humid air — and odors — out of the home. Make sure the fan you choose is powerful enough to ventilate your bathroom.

Use the room size to determine the necessary cubic feet per minute ( CFM ) rating of the . Watch this video for tips on how to determine the correct size ventilation fan you need for your bathroom , based on the bathroom size and airflow of the fan.

The size or capacity of the exhaust fan you need is determined by the type of room it is to be installed in, as different rooms require different rates of air flow. The rate of air flow is determined by the number of complete changes of air within the room per hour. For example: A bathroom without shower requires 6-changes of .