Extractor Fan in small office

[leevis]

Hi

I am currently in the conversion phase of a small office which is an old converted kitchen in my house. This will not have any windows and i need to put in an extractor fan to turn the air when required.

The current electrics have lights and thats about it so i was thinking of taking a feed from those to power the fan. Since the lights are going to be on most of the time when it is used i would rather it wasnt in operation all of the time, not too sure if these can be set so that they go on when the light is turned on and then turn off after a while and then on again.

I have a couple of the hydrostatic ones which work quite well but as there will not be anything in there that would set it off i doubt these are going to be of any use.

I want a really quiet one if possible.

Is this possible, anyone want to spec one?

 

[leevis]

Just noticed that there is an existing 'hole' for a tumble dryer in there, would it be easier to get one of those new inline ones and connect that to the hole and have it on the floor? Might be less of a pain in the neck

 

[johnny2007]

Fit an extractor fan isolator in line.
All newer installations I have seen have one.

 

[leevis]

Are they OK at ground level? I was thinking of getting the unit and putting it in a box with a vented front?

 

[johnny2007]

You can place the isolator wherever you want, I don't know about the fan though.
I've always fitted extractor fans up the wall.

 

[Harry Bloomfield]

Are they OK at ground level? I was thinking of getting the unit and putting it in a box with a vented front?

Providing there is an obvious place for the replacement air to flow in from, preferably at an opposite corner to where the fan is located, the fan will do what you expect. You can get fans which run while ever the light is on, or a period after the light goes off and/or ones which are PIR triggered and/or humidity triggered. I have never come across one which only runs for a preset period after a light has been turned on, so you would have to devise a control for that.

 

[JohnD]

Water vapour is lighter than air so it rises towards the ceiling. So extractor fans are usually mounted up high.

Warm air does the same.

The "Silent 100" model branded Envirovent or Soler & Palau is a very good and quiet little fan.

The power you need depends on how big the room is, and what you use it for.

Why do you want the ventilation to stop while the room is still occupied?

 

[oldbutnotdead]

Might be best linking to a CO2 detector so the thing will chime in and out when the room gets stuffy- you might need a relay to interface the 2 but nowt complicated.

 

[leevis]

The room is an old kitchen which I am in the process of turning into a kitchen. I have the Silent 100 in the new kitchen and seems to work well but i got the humidistat version.

There is only one light fitting in there at the moment so will be taking the ceiling down and putting up some downlighters (probably 4) and was going to take a feed off of the lighting to power the extractor fan but as the lights are going to be on whenever it is occupied, i'd rather it wasnt on all the time as can get annoying and you can certainly hear them when they are on.

I will be fitting an isolator between the lighting and the fan so i will have a manual on off should i need it.

There are quite a few models of the Silent 100 Design which i like, not too sure whether the humidistat version is worth it as there will be no vapour in there. That being said i suppose i could set it to 60% and i will probably go off a fair bit.

I am guessing that i can just add this to an existing lighting ring on the end? ie from the last light > into an isolator > into fan?

 

[JohnD]

Might be best linking to a CO2 detector so the thing will chime in and out when the room gets stuffy- you might need a relay to interface the 2 but nowt complicated.

IMO running continuously will be less irritating than going on and off.

 

[leevis]

Yeah thats true tbh.

 

[bernardgreen]

Are they OK at ground level?

One advantage of a ground/floor level extractor fan is that it will extract the colder air and not extract and waste the warm air near the ceiling.

 

[leevis]

Guessing that is a disadvantage, Ill get a hole done

 

[mattylad]

Your desired on/off can easily be done if you get a timer module, they can do on/off periods with auto reset etc.

 

[Harry Bloomfield]

If it proves to be too noisy, some fans can be slowed down to reduce the noise.