Inline fan switched from two locations

[S P]

Good evening all,

Has anyone ever installed a fan like this before?
The issue I don't know the best way to overcome is that if I wire each bathrooms SL to the fan it will back feed and turn the lights on for both bathrooms.

The best I've come up with is 2x contactors - one SL to each input - then both outputs to SL on fan isolator. L+N from both junctions straight to fan isolator.

Is there a better way of doing this?

I thought it would be a good idea as it is serving two small back to back en-suites, accessible loft space above for the fan. They are much more powerful than the standard wall/ceiling units. Plan was one duct out - Y joint at fan to each room.

The contractors will cost around £55 so unless someone knows a better solution it makes more sense to install two fans.. They cost £65 each

Thank you

 

[elsparko]

DP switch much easier. However, if you opt for two fans, sharing one extract duct then you'll need to consider the issue of air backfeed from one room into the other.
The last thing you want is Vindaloo poo from one room being pushed back into the other. To solve that you'd need two backdraft flaps in the two fan outlets, and probably a larger outlet duct after the Y piece to cater for when the two fans are going at the same time.



So two fans not so simple a solution.

2 fans, 2 ducts, 2 vents

bish bash bosh

 

[Taylortwocities]

Are you really an electrician, or a ventilation engineer.

2 switches (he'll need that anyway)
one fan (half the price of two fans)
Ducts and vents (he needs that anyway)
Cable (he needs that anyway)

what's not to like?

 

[S P]

Thanks guys - DP switch is how I'm going to go

Richard - thanks for the diagram that makes perfect sense now.
I couldn't visualise it - I was thinking people meant a 2g switch which wouldn't have turned fan on with light.

 

[elsparko]

what if a bird makes a nest in that 1 vent, thats 2 fans blocked

Are you really an electrician, or a ventilation engineer.

2 switches (he'll need that anyway)
one fan (half the price of two fans)
Ducts and vents (he needs that anyway)
Cable (he needs that anyway)

what's not to like?

both fans will always have to be on with eachother, save the planet bro, dont waste leccy

 

[Taylortwocities]

Eh? Me no understand.

With DP switch solution - and one fan - then there's only one fan to power, no matter even if both bathrooms are in use.

With two fans, its double the ice-cap melting power if both rooms are in use at the same time.

what if a bird makes a nest in that 1 vent, thats 2 fans blocked

Come on, get real. There's a vent grill on the outside.
But, I suppose that a squirrel could pull that off, crawl up the duct, unwire one of the fans and take it back to his nest. Then I guess its worth having a second fan in that case.....

 

[elsparko]

Eh? Me no understand.

With DP switch solution - and one fan - then there's only one fan to power, no matter even if both bathrooms are in use.

With two fans, its double the ice-cap melting power if both rooms are in use at the same time.


Come on, get real. There's a vent grill on the outside.
But, I suppose that a squirrel could pull that off, crawl up the duct, unwire one of the fans and take it back to his nest. Then I guess its worth having a second fan in that case.....

lol right enough, dunno what planet i was on when i wrote that earlier, i meant the fan would be pulling air from both rooms even when only 1 room is in use.

ive replaced dozens of fans that had a dead bird/mouse lodged in the blades

not really a fan of inline fans though, would rather have the air pushed out from the source

 

[Des 56]

[QUOTE="Taylortwocities,
However, if you opt for two fans, sharing one extract duct then you'll need to consider the issue of air backfeed from one room into the other.
The last thing you want is Vindaloo poo from one room being pushed back into the other. To solve that you'd need two backdraft flaps in the two fan outlets, and probably a larger outlet duct after the Y piece to cater for when the two fans are going at the same time.
[/QUOTE]

Before the smoking ban,the concert hall in my local club had ducting out through the roof with 2 fans sharing one poorly designed ducting
Operate just the one, the smoke mixed with the air being dragged in from outside, the freezing cold smoke would all be dumped on the poor dears up the front

The committee men never did learn to operate both together