Bath Exhaust Fan Duct Length

Enter bathroom width ft.

Bath exhaust fan duct length.

Here we provide specifications for recommended minimum maximum duct lengths for bathroom vent fans. If the enclosed space is small a 50 cfm fan should suffice. A bath vent fan duct that is too short may violate the manufacturer s installation instructions may not work properly or may be drafty. A bath vent fan duct that is too long may restrict air flow such that the fan is not functional.

Otherwise use the appropriate calculation based on the room size. Enter bathroom height step 4. Suggested cfm for the bathroom is based on cycling all the air in the bathroom 8 times per hour. Result maximum recommended length of straight duct in compliance with 2015 irc section m1506 2 and 2018 irc section m1504 2 ft 0 ft nl no limit on duct length for the specified system.

Just remember that the fan needs airflow to do its job. Enter bathroom length ft. If your bathroom has a toilet or shower area enclosed by a door it s a good idea to install a separate exhaust fan for that area. Press calculate minimum suggested bath fan cfm.

The bathroom exhaust ventilation fan disperses air through an opening in the fan housing which is usually 3 inches in diameter and ideally faces in the direction of the ventilation system outlet. Bathroom exhaust fan duct length specifications. A 3 or 4 inch duct connects to the outlet on the fan housing and runs to a side wall or to the roof and connects to a vent cap that allows the.