Two extractor fans in one room?

[spiidey]

I'm laying insulation between our ground floor and first floor and there are two extractor fan pipes running to the same location on the outside of the house (see first pic) and which both appear to be running to the same location in our house (above the downstairs toilet).

In the downstairs toilet, there appear to be two extractor fans on the ceiling (see second and third pics). Are these both extractor fans and if so, why on earth would there be two?

Finally, in terms of switches to control the fans (see fourth pic), on the outside of the downstairs toilet there are three switches -

the double switch socket which controls:-
the downstairs toilet light (left hand side of switch)
the hallway light (right hand side of switch)

the "Isolator" switch which doesn't work but I'd hazard a guess controls one of, or both fans?

All very odd!!

 

[PrenticeBoyofDerry]

Yes seems odd to have two ex-fans in such a small location.
So how can you be helped?

 

[skenk]

The round thing is a vent/grille, not a fan in itself. In a normal scenario you would expect to see an inline fan somewhere along the ducting for this vent.

No idea why it's been done like that.

 

[AndyPRK]

Is one air in
and the other air out via fan

 

[bernardgreen]

Could one be extraction and the other inward to supply replacement air ?

 

[spiidey]

Yes - quite possibly one could be air in and one air out, as the downstairs toilet has no external window.

How would we be able to determine whether one was air in and one an extra for fan - the grills on the outside of the house?

Reason for asking is where we want to lay insulation, whether we could robe one of the White poly tonnels or not.

 

[ban-all-sheds]

I'm laying insulation between our ground floor and first floor

Why?

Are many of the 1st floor rooms unused?

 

[spiidey]

External pic - seems to be same type of grill for each.

Have also had a look and doesn't appear to be any inline fan - although what should that isolator button be controlling?

 

[AndyPRK]

I guess only the square one makes a noise ? Ie is a fan

 

[spiidey]

I'm laying insulation between our ground floor and first floor

Why?

Are many of the 1st floor rooms unused?

There seems to be a draught coming into the void which is resulting in our living room being freezing and taking ages to heat up in the winter.

 

[spiidey]

I guess only the square one makes a noise ? Ie is a fan

The isolator button (if this does indeed control the square one) doesn't actually work!

 

[AndyPRK]

Maybe the fan broke years ago.

Apart from fixing it (if it's broke) just leave it alone

 

[ban-all-sheds]

Find and fix the source of the draught.

And be prepared for increased condensation, mould problems etc if you do too good a job of sealing the place up.

 

[AndyPRK]

So if u put the isolator down
And turn on the light it doesn't work ?

 

[spiidey]

Yeah we'll just need to air our house better once sealed.

Yep - isolator down and toilet light on, and fan still doesn't work.