ceiling extractor fan

[mercedesjb]

i am wanting to fit an extractor fan in the ceiling of my bathroom

1. should it preferably be away from above the bath ?
2. do i need a 'centrifugal' type fan?
3. would i attach ducting and run up to the roof with the appropriate trap and tile replacement?
3. finally how do i connect to the lighting circuit so it comes on when i pull the light cord

 

[pdcelec]

install it to BS7671 and the building regs and it will be fine

 

[delmel]

site it farthest away from any natural air source ie window and also a decent idea to keep out of reach from the bath if poss.
Centrifugal is used id duct runs are longer above 2 mts i would suggest using one.