Extractor fan advice, kitchen and bathroom?

delmonta

Hi, I've just had my house externally insulated. They have made holes for extractor fans, a larger one in the kitchen. It seems they have just bought the cheapest fans you can get, no timer, no brand, probably very noisy once they hook them up! So at some point I'll change them, but they've already fitted these so I'll see how they go

But I was wondering a few things...

- Do I need extractor fans with a timer? My bathroom has a decent size window, which spends a fair bit of time open. The kitchen has a big window and French doors. 

- Do you get extractor fans with isolating switches, or do you have to wire one in separately? I'd like to be able to turn the fan off even when the lights are on at times
- In the bathroom the lights are only 2 core, can you get fans that only require that?

FaceHead

- Do I need extractor fans with a timer? My bathroom has a decent size window, which spends a fair bit of time open. The kitchen has a big window and French doors. 

Whether you need one at all is up to you, and possibly building control, and again whether it needs a timer is situation specific on how damp the room would be without one.

- Do you get extractor fans with isolating switches, or do you have to wire one in separately? I'd like to be able to turn the fan off even when the lights are on at times

Most manufacturers specify that is has to be on a double pole isolating and/or a fuse. You'll have to refer to the instructions for the one you want. To get the behavior you want i.e being able to operate it with or without the lights, clearly you need some sort of isolator or secondary switch for it. 

EDIT: I've never seen one where there is a local isolation switch - The switch will usually need to be outside the bathroom, so it a separate item.

- In the bathroom the lights are only 2 core, can you get fans that only require that?

Yes. The ones without a timer or humidistat, which will go off as soon as you turn the light off. You'll need 3-core and earth if you want the timer or humidistat. I'd recommend the humidistat - I have a timer in my bathroom, and it irks me how it stays on unnecessarily If you go to the loo, but might go off prematurely after a shower. As it is wired with 3-ore and earth (to enable the timer) it will be an easy swap to humidistat if I feel like it. 

delmonta

FaceHead said:

- Do I need extractor fans with a timer? My bathroom has a decent size window, which spends a fair bit of time open. The kitchen has a big window and French doors. 

Whether you need one at all is up to you, and possibly building control, and again whether it needs a timer is situation specific on how damp the room would be without one.

- Do you get extractor fans with isolating switches, or do you have to wire one in separately? I'd like to be able to turn the fan off even when the lights are on at times

Most manufacturers specify that is has to be on a double pole isolating and/or a fuse. You'll have to refer to the instructions for the one you want. To get the behavior you want i.e being able to operate it with or without the lights, clearly you need some sort of isolator or secondary switch for it. 

- In the bathroom the lights are only 2 core, can you get fans that only require that?

Yes. The ones without a timer or humidistat, which will go off as soon as you turn the light off. You'll need 3-core and earth if you want the timer or humidistat. I'd recommend the humidistat - I have a timer in my bathroom, and it irks me how it stays on unnecessarily If you go to the loo, but might go off prematurely after a shower. As it is wired with 3-ore and earth (to enable the timer) it will be an easy swap to humidistat if I feel like it. 

Thanks, ok so I'd need a separate pull cord switch probably. The cheap one they have for the kitchen appears to have a small pull cord coming out of it. So this must be an on off switch? 

I also find it annoying when fans stay on when you just go into the bathroom and dont create any humidity! Thats why I want the isolator. The humidistat ones look nice, but also a bit out of my budget right now

daivid

I have recently had an extractor fan installed in my bathroom that did not have a fan previously. I went for an inline fan as on paper they shift a lot more air, also the motor is not in the room so this makes it very quiet - good for a peaceful bath. I went for separate switches and no timer, so I can have light & no fan to go to the toilet or brush teeth or fan and no light if having a bath/shower in daylight. If I was in the habit of showering just before leaving the house I would have asked for a 15min timer but as I'm not I just leave the fan as I think is necessary.

Emmia

We had new vent axia fans installed with a humidstat (no windows in the bathrooms) and they are significantly quieter than the cheaper vent axias they replaced (I looked at the db ratings and extraction rates when selecting them to get quiet but effective fans...) - ours have a separate switch above the doorway outside the bathroom controlling the fan  but we don't tend to turn them off at at all... 

The thing with a humidstat is that if the humidity goes over a certain level, the fan will come on at low speed (it's pretty quiet) for a few minutes, even if the light is off and it is 3am! As we have no windows in the bathrooms this is definitely a plus, but if you want no fan noise at all unless you're  bathing/showering then you may want to consider that.

Screwfix have a good selection of fans, and the db ratings & features are easy to see and compare.

Alanp

I’ve recently changed out my humidistat controlled bathroom fan, it packed up so I took the opportunity to get rid, it would come on during those humid days we get in summer, it would stay on for hours no matter what the setting was at, so I replaced it with a timer version, we haven’t got a large window in the bathroom as we changed it when we altered it, so we tend to have the light on most times when using the bathroom.

Chickereeeee

I have an inline fan also, and it has the option of a timer. I have it wired it on a separate pull-cord, so it doesn't come on with the lights. You can switch it on when you start your shower, and off when when you have finished. It will then run on for about 15 minutes (selectable) to clear any moisture from the room after you have finished.
So, no activations in the night, or when you don't want it, no premature turning off during a shower, much less moisture in the bathroom due to the run-on, and no accidently leaving it on for hours because you forget to go back and turn it off. And if you want a quick burst, an on/off cycle gives you 15 minutes of extraction.

delmonta

Thanks everyone. My bathroom is quite small but has a large window which opens wide. The insulation people just put a standard on/off fan in without asking me, it has no timer. It has a little pull cord hanging out the bottom I guess so you can isolate it if it's wired to the lights. 

I imagine this will be fine, as we tend to open the window when showering anyway, and in summer its open all the time. 

I hate noisy fans, especially if you want the lights on and want to have a bath

Thanks for all the advice