Bathroom Ventillator Fan Position

[Yaz K]

I'm installing a ventilator fan in the bathroom but the location is causing a dilema. The outside wall is around 12 feet from the shower area so if I fit a wall fan, will it take be efficient at removing the steamcaused by the shower? The alternative is a ceiling fan directly above the shower area but then will a 12 foot duct out to the wall / roof be too long? Thanks for any advice.

[Nick Finnigan]

The (Marley 5") fan I fitted recently came with 3m of flexible ducting, and claims to move 180 m^3 /hour at most;

72m^3/h with 1m of ducting, 65m^3 /h with 2m of ducting.

Neither option looks great for such a large bathroom, so I'd probably go for the most convenient.

[fred]

In article , Yaz K writes

Have a think about where the air will be coming in to replace the damp air removed by the fan. If it is being draw past the position of the shower, say from a door at that end of the room, then I'd be happy to have the fan on the outside wall, but if the door is at the outside wall end, I'd duct one in.

I have put in a ducted one, but placed the inlet just near the shower area as I thought a meaty fan inlet just above my head would be noisy & draughty. 12' would not be a problem for a decent ducted fan.

[Owain]

"Yaz K" wrote | I'm installing a ventilator fan in the bathroom but the location | is causing a dilema. The outside wall is around 12 feet from the | shower area so if I fit a wall fan, will it take be efficient at | removing the steam caused by the shower? The alternative is a | ceiling fan directly above the shower area but then will a 12 foot | duct out to the wall / roof be too long?

The air flow will take the easiest route, so it depends on where the window or door is, because that is where the air will come from that replaces the air being extracted.

You should avoid air being sucked door > loo > washbasin > fan unless you want bacteria-laden aerosolised shit from the loo being wafted over your toothbrushes.

Points to consider:

1. If you mount a fan directly above the shower it may have to be a low-voltage one to comply with the electrical Zones in bathrooms (google for this).

1. 12 ft of ducting is nothing for a half-competent centrifugal fan (one designed for ducting, not the piddly little 4" axials the sheds sell) but it may be harder to find one in low-voltage. If you have the space, you can mount the fan part-way along the ducting. Consider noise/vibration.

2. If ducting, have the ducting slope away from the fan all the way, so condensation in the pipe runs out (or install a condensate trap with drain). My bathroom fan must go through about 40' of ducting.

1. Consider getting one with an integral humidistat.

[Chris J Dixon]

If ducted, there is no need for low voltage, the fan is outside the zone.

Chris