Bathrooom heat recovery extractor or simple extractor fan ?

[Talay]

I want an extractor fan installed in the bathroom and I would like it humidity controlled.

So I can get a cheap fan like this http://www.tlc-direct.co.uk/Products/ADAUE100HT.html or a more expensive one like this http://www.amazon.co.uk/Xpelair-Bathroom-Centrifugal-Extractor-Humidistat/dp/B004TQ0POC or you can go the whole hog and go for a heat recovery model like this http://www.amazon.co.uk/Kair-Heat-Recovery-Extractor-Fan/dp/B004VW3RGW which is significantly more expensive.

So is it worth paying more and what are the real points which I should look out for when choosing a fan for the bathroom ?

Also, what level of humidity should I aim for ? Some go down to 60% and others 40% ?

 

[stem]

Cheaper fans usually work OK, but in my experience, they don't always last all that long and tend to get noisy bearings, vibrate or rattle. With basic fans as with most things, you tend to get what you pay for.

If you don't have a damp problem and just want a fan to run for a while to clear the bathroom of steam post showering, 60% would probably be OK for you, however, it might not stay on whilst the towels are drying, whereas a 40% fan would would keep going for longer. (I'm not sure what our maximum humidity levels are in the UK, but you may find on a humid day, that the ambient humidity might be in access of 40% so the fan may run continually)

With the fan with a built in heat exchanger, they are normally used for continual ventilation as they can be left on a trickle (very slow) setting continuously. Because they are designed for continuous use, the advantage here is that much of the heat in the outgoing air is transferred to fresh air that is blown into the room from outside via the side vents so not much heat is lost from the room, unlike a normal extractor.

How well the boost setting works I dont know. With a correctly sited traditional fan, air is sucked out of the room and replacement air is drawn in under the door, via window vents etc., so that fresh air is pulled across the entire room (or as much of it as possible) The heat exchanger type, comes with two fans, one blowing 'in' and one blowing 'out'. As they are combined in the same unit, the effect of drawing the air across the room is lost.

If you just want to ventilate the room post showering and don't have a condensation issue with your bathroom, I would go for a good quality 60% fan.

If you require that extra ventilation, then the 40% would probably be more useful.

If you want continual ventilation then the heat exchanger version would be worth the extra outlay, probably not so if you just wish to use it for a short time after showering IMHO

Personally I have a simple extractor controlled by a PIR sensor with a run on timer set to 15 minutes. This keeps the fan running for 15 minutes after the room has been vacated. The advantage here is that it also works when the fan may be required for activities that don't generate steam