Bathroom extractor from 2 bathrooms

[oceanbassboy]

Hi all,

I am currently planning upgrade of two bathrooms to which I need/want to fit extraction. Is it possible/legal/advisable to fit one extractor motor in the attic with ducting from both shower areas switched from both light pulls?

Thanks in advance for any advice.

 

[bernardgreen]

Not really advisable as the complexity of the electric switching and the need to ensure balanced extraction from both rooms might cost more than having a pair of fans.

Switching will require two pole light switches to provide two independent switched lives per room, one for the light and one for the switched live to the fan. Then the fan may not recognise it's switched live as being OFF if there is no lamp to pull it's switched live towards Neutral when OFF

Air balance will need care. The bathroom in use will have its door shut. ( normally ) and the other bathroom door may be open. It will be easier for the fan to pull air from the room with it's door open than from the room with it's door shut.

 

[oceanbassboy]

Thank you for swift and sound advice. Very useful points, looks like two seperate fans.