25 1/4" Fans | McMaster-Carr

Measured in decibels (dB), volume ratings indicate how much noise equipment makes. Some common volume levels include a whisper @ 20 dB, a refrigerator @ 40 dB, a conversation @ 60 dB, and a light machine shop @ 90 dB. OSHA recommends hearing protection for exposure to 80 dB and greater.

Direct-Drive Upblast Roof-Mount Exhaust Fans

Direct-drive fans have fewer moving parts than belt-drive fans for less maintenance. These exhaust fans draw stagnant and humid air out through your roof and then expel it up and away from the roof surface. All fans have a disconnect switch to turn off the power for servicing.

Fans with a brushless motor have advanced electronic controls that allow them to precisely operate at wide range of speeds, making them more efficient, quieter, and longer lasting than fans with a standard motor.

Note: Airflow depends on the resistance created by ductwork. This resistance, known as static pressure (SP), is measured in inches of water.

Fans
						Overall									Mounting Bases
	Blade Dia.	Airflow @ Static Pressure	Volume	Motor Speed, rpm	Power, hp	Dia.	Ht.	Base Wd.	Wt., lbs.	Max. Ambient Temp., °F	Housing Material	Specifications Met		Each		Each
Open Dripproof Motor Enclosure
120V AC, Single Phase—Hardwire
1	11 3/4"	750 cfm @ 1/2 in. of H₂O 1,050 cfm @ 0 in. of H₂O	59 dBA @ 5 ft.	1,300	1/4	25 1/2"	25 1/4"	21"	67	300°	Aluminum	AMCA Certified, ETL Listed	0000000	0000000	0000000	0000000
1	12"	1,100 cfm @ 1/2 in. of H₂O 1,300 cfm @ 0 in. of H₂O	68 dBA @ 5 ft.	1,625	1/3	25 1/2"	25 1/4"	21"	50	300°	Aluminum	AMCA Certified, ETL Listed	0000000	000000	0000000	000000
Totally Enclosed Motor Enclosure—Brushless Motor
120V AC, Single Phase—Hardwire
1	11 3/4"	1,050 cfm @ 1/2 in. of H₂O 1,300 cfm @ 0 in. of H₂O	70 dBA @ 5 ft.	1,575	1/3	25 1/2"	25 1/4"	21"	64	300°	Aluminum	AMCA Certified, ETL Listed	0000000	000000	0000000	000000