How to choose a bathroom extractor fan?

rowly731

Hello everyone

our bathroom is very steamy (and I don't mean in a good way) and we want to get an extractor fan. We are set on a wall mounted unit but not sure what flow rate we need.

I saw some advice on an extractor fan website (fantronix) that rooms upto 10m3 need a flowrate of between 77-86 m3/hour and bathrooms between 10-25m3 need a flowrate of 149-168m3/hour.

The room is approximately 10m3 but I would rather have a fan that is overpowerful (within reason) than something that would just about manage.

I guess my question is does anyone have any thoughts on what sort of flowrate I need.

Also I want a timer but is a humidity sensor worth investing in?

Many thanks in advance

penguingirl

rowly731 wrote: »

Also I want a timer but is a humidity sensor worth investing in?

I have no idea about flowrate, but we recently got a humidistat extractor fan (we bought this one in b&q- if you want a pic it looks just like all the other white manrose ones b&q sell) and have been really pleased with it- it just made sense to us that it would come on when it's needed and not just because someone has the light on or remembered to switch it on. You can connect that one to the light, but we haven't, so it only comes on when it senses humidity (I have a real hatred of fans that come on when you go to the toilet in the night!)

ic

I think the humidity sensor is well worth it - if you shower and its daylight you don't have to unnecessarily put the light on (and risk forgetting to turn it off), and it'll run for as long as is needed, rather than just do the preset time and then give up. It also means that you don't even need to have the fan come on with the light, or if you do, only for a short period - so if someone nips to the loo in the night, the whole house doesn't have to lie there listening to a fan chugging away for a preset 20 minutes.

I've got an Icon Airflow 30, which is capable of 118m3/hr. The Airflow 60 is capable of 260m3/hr. Available with a variety of run options, including the humidity.

Things you need to consider are where it will be installed, where it will vent to, the length of the vent, and how close to any water it'll be (i.e. do you need a low voltage installation = more cost). This is a job for an electrician due to being in the bathroom. I'd guess if you can site an extractor in the ceiling above the shower, you'll probably find it is more effective at clearing the steam.

There's a calculator available here: http://www.tlc-direct.co.uk/Technical/Ventilation/Ventilation4.html