Bathroom Fan – 18W

The VO-FN4W18-AC-50 is a 50 CFM ceiling exhaust fan for powder rooms and half baths, ENERGY STAR certified in Canada and the US at 3.0 CFM/W.

Fifty CFM through a 4 in. duct, and it still holds 43.4 CFM at 0.25 in. w.g. Single speed, continuous-run rated, 0.15A.

Galvanized-steel housing, dual ball bearing motor, thermal fuse and damper built in. cETL listed for insulated ceilings and over a tub or shower on a GFCI-protected branch. HVI certified. 2-year warranty.

Is 50 CFM enough for a bathroom fan?

Yes, for a bathroom up to about 50 square feet. The rule is 1 CFM per square foot of floor area, so 50 CFM suits a powder room, a half bath or a small full bath. An enclosed shower, a soaking tub or ceilings over 8 ft need more air, and the 80 and 100 CFM models cover those.

Can you have too much CFM?

Yes, and it costs you twice. An oversized fan pulls more heated or cooled air out of the building than the room needs, and the manual lists "CFM too great" as a cause of a fan running louder than it should. Match the rating to the room, not to the opening.

Will it replace an existing fan?

Usually. The grille is 13 in. x 13 in. over a 9-1/4 in. x 9-1/4 in. opening, so it covers most existing cut-outs without patching. Two cautions. The manual warns that fans reusing existing ductwork may not reach rated airflow, and this unit discharges through a 4 in. duct. Don't adapt it down to a 3 in. run, because that costs airflow and adds noise.

What the ENERGY STAR listing confirms

VO-FN4W18-AC-50 is certified for the US and Canada, qualified 2025-07-11, at 50 CFM and 3.0 CFM/W. That clears the 2.8 CFM/W minimum for the 10 to 89 CFM class. The certification ID and UPC are on the register, so both are quotable on submittals.

Installation limits worth knowing

Keep the first duct elbow at least 18 in. from the discharge, and run the duct short and straight. Branch-circuit wiring is 14 AWG minimum. It won't work on a dimmer or any solid-state speed control. It isn't a range hood, and it can't go in a cooking area or where air temperature passes 104F. The manual caps ceiling insulation at R40, so confirm the assembly before specifying it into a new Ontario attic. Junction box, wire nuts, duct and clamps aren't included.

For the wiring diagram, the duct routing do's and don'ts and the eight-step sequence, open the Manual (PDF) in the Related documents panel, and take the Spec sheet for dimensioned drawings. Send us your unit count and ceiling type and we'll come back with a wholesale quote and the right fan for the room.