Extraction fan in a bathroom

old school sparks

I totally agree with your last point.  no they do not.  

geoffsd:

Another 62 pages of guidance; what are the actual regulations?

As above, the regulations just call for "adequate" ventilation. So (where building regs apply) simply choosing not to provide any means of ventilation isn't an option. The next question is what is "adequate" - here the guidance documents (AD F and the DFCG) are useful as they set the bar of what is likely to be considered adequate. While you're free to choose some other approach if you prefer, if it doesn't perform as well (or is less convenient to use properly) as the approaches suggested, then you're unlikely to have met the 'adequate' requirement.


   - Andy.

Clint:

I have no where for the transformer to go, it won’t have an 3point isolation point. It will be straight from light fitting and will come off once the light is off. There is no way to get a 3core from switch without destroying the room. It’s a flat roofed , no access from above the room, joists run across meaning a big strip would need to be taking out of ceiling along with a chase down the wall to the switch. So going from the light fitting to the fan is only way without destroying my house. The fan is at opposite side of bath, so about 1m from shower and about 1.5m from bath bowl.

 

The original question was he has found a fan "Monsoon MON-S100T" and goes on to say  the above. I have read the instructions.  After reading the instructions for the fan, and without at least a minimum a switched fuse spur, this will not comply with manufacturers instructions, and to comply with current wiring regulations you must follow manufacturers instructions.


So to simply answer the original question without means of isolation, no its not ok to use the Monsoon MON-S100T fan, forget any other regulation it may or may not comply with.

geoffsd:

Of course, but previous posters claimed that The Building Regulations state that a bathroom fan must be fitted - and therefore must be  legally compulsory.


Further, it was even claimed that The Building Regulations state that a timed run-on must be incorporated - and therefore must be legally compulsory.


Neither is true.

Statute requires "adequate ventilation". The approved document and other guidance such as The Electrician's Guide to the Building Regulations provide guidance as to what is adequate. Adequate ventilation includes purge ventilation which may be achieved by having at least one opening window of sufficient size, or a fan with a 15 minute overrun.


The work described in the OP may fall outside the scope of the Building Regulations, but in any applicable work, it would seem foolhardy not to provide a switched line and an un-switched line.


Incidentally, I am not convinced that a 3-pole isolator is necessary, but it is desirable.