Bathroom extractor fans

[guinea]

Fitted some ceiling timer fans in bathrooms with no openable windows. A couple of the fans have failed, it looks like condensation has formed inside the fans causing fault across terminals. Has anyone come across similar problem ?

 

[Octopus]

Cheap fans don't last long these days!

 

[HappyHippyDad]

If it has a loft then I would always fit an In-line fan, so that any condensation forming will not go onto the electrics, plus keep the ducting fairly taut so that condensation doesn't get trapped and the air flow is better.

Do the maufacturers instructions say they are suitable for ceiling mounted? And how long is your ducting run usually Guinea? Plus if there are no windows then you will need a suitable vent to allow air into the room otherwise the fan will not be able to do its job efficiently and there will be more condensation.

 

[dingledong]

Never come across that ! I have had one in the ceiling that when you took the cover of I got soaked as it was full of water from condensation

 

[Richard Burns]

If you have a fan in the ceiling and there is any vertical uninsulated ducting above it then when the warm moist air is blown up the duct into the cold loft space then the condensation forms on the cold duct and runs back down to the fan, in these cases there should be a condensation trap fitted that can drain away the condensation (though where to is always a logistical nightmare) before it reaches the fan.

 

[Perci]

Need to make sure the condensation runs to the outside. And that the ducting is insulated as it can cause legionnaires disease from standing water.

 

[sparksburnout]

If you have a fan in the ceiling and there is any vertical uninsulated ducting above it then when the warm moist air is blown up the duct into the cold loft space then the condensation forms on the cold duct and runs back down to the fan, in these cases there should be a condensation trap fitted that can drain away the condensation (though where to is always a logistical nightmare) before it reaches the fan.

This is a very good point Richard, and one not easy to do in my opinion. I have never been happy installing these things, particularly when there is a decent horizontal run of ducting. The logical thing is to keep it under the loft insulation and hence stop some of the condensation forming, but then you need more robust ducting and an inline fan that can be covered. If your not careful a simple bathroom ceiling extractor can turn into quite an expensive almost semi-industrial installation. As you say finding somewhere for a trap to drain into is often near impossible!