extract fans

[keniff]

does anyone know if what im saying is correct, if a bathroom or anywhere that needs an extract fan has natural light the fan does not need to switch on with the light, if the room has no natural light the fan HAS to activate with the light. i cant remember but was having a convo with another spark today

 

[flukey]

if the bathroom has natural light and the fan is supplied from lighting circuit then it doent need an isolator.
if no natural light then it does

hope ive interpreted your question right

 

[keniff]

Thanks flukey, I mean actually activated when the lightswitch is turned on, does it have to be like that on all installations

 

[nickblake]

if the bathroom has natural light and the fan is supplied from lighting circuit then it doent need an isolator.
if no natural light then it does

hope ive interpreted your question right

think you may find that the fan requires a means of isolation even if it does have natural light as most fans these days have a permernat feed so this needs as you are aware isolating and also if you are replacing the fan rather than isolate the complete lighting circuit which may have dark area it can be isolated locally ,also stops little mrs jones switching the light on when you are working on it ,need more light my dear if you see what i mean, the question regarding the light and switch where a bathroom has natural light i will install a movement sensor , this way the fan can operate when its light or dark

 

[flukey]

think you may find that the fan requires a means of isolation even if it does have natural light as most fans these days have a permernat feed so this needs as you are aware isolating and also if you are replacing the fan rather than isolate the complete lighting circuit which may have dark area it can be isolated locally ,also stops little mrs jones switching the light on when you are working on it ,need more light my dear if you see what i mean, the question regarding the light and switch where a bathroom has natural light i will install a movement sensor , this way the fan can operate when its light or dark

have to disagree there nick will back it up with a reg when i can be arsed to move
top of page 62 egbr until i find my red book

 

[Des 56]

does anyone know if what im saying is correct, if a bathroom or anywhere that needs an extract fan has natural light the fan does not need to switch on with the light, if the room has no natural light the fan HAS to activate with the light. i cant remember but was having a convo with another spark today

My age old question
Why would you want a ventilation system controlled by the intensity or lack of light
Is it not better to control a ventilation system with regard to when its necessary to extract the air

 

[Adam W]

My age old question
Why would you want a ventilation system controlled by the intensity or lack of light
Is it not better to control a ventilation system with regard to when its necessary to extract the air

If the room had no natural light you would nearly always turn on the light upon entering, whereas someone might not necessarily turn on the fan, thereby effectively making the pullcord an occupancy switch. The fan is not just to remove excess moisture but smells as well; as far as I know there isn't currently a sensor available that can distinguish between air freshener and undesirable body aroma.

 

[keniff]

ok, just to clarify things, is there a reg that says you have to have the fan come on with the light at the same time? i cant seem to find anything!!

 

[flukey]

not one that i know of but i stand to be corrected.

as previously said the light and extractor serve different purposes and are normally combined for ease of use

 

[ezzzekiel]

no, and if there is a window then there is no need for an isolator, although everyone tends to fit them regardless