Building Exhaust Fan Sizing

Use this table to calculate the cubic feet per minute cfm capacity needed for an exhaust fan in a specific room.

Building exhaust fan sizing.

The results are highly variable areas around doors and windows will be well ventilated while pockets of stagnant or contaminated air can build up in other areas. Exhaust fans force out stale indoor air so it can be replaced by fresh outdoor air. One pound per square inch is equivalent to 27 7 sp. 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.

Sizing and finding high quality low maintenance exhaust and air movement equipment can save money for agencies and business owners. A pressure differential between the duct and the. Commercial and industrial ventilation can be expensive to install or update and finding the right type and size of fan will keep companies and industries in compliance with codes and regulations. Fan ventilation fan assisted ventilation overcomes these problems.

A ventilation fan should meet at least the minimum standard cfm to provide proper exhaust. 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. It removes hot moist air and it can remove odors. Static pressure in fan systems is typically less than 2 sp or 0 072 psi.

Its performance depends on the size and position of the doors and windows and natural airflow patterns. The exhaust fan drawing below illustrates how static pressures are measured in ductwork with a manometer. Belt driven exhaust fans handle large volumes of air at. Bathroom exhaust fans or vent fans are required by the nec national electrical code and local building codes for any bathroom that doesn t have a window that can be opened to provide ventilation and in some jurisdictions they are required even if windows are present a vent fan does two important things.

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. Sizing an exhaust fan use this table to calculate the cubic feet per minute cfm capacity needed for an exhaust fan in a specific room. Exhaust fans mount through a cutout in a roof or wall. 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.

Before you install bathroom kitchen or garage exhaust fans start here to determine what you need to proceed for. They re commonly used to reduce moisture and remove smoke and odors in restaurants residences shop and production floors and commercial buildings.