Exhaust fan for attic.

[Lemne]

We only have our attic for storage and in the next few weeks will be adding shelving up there. We're in a flat and the roof has around 8 small open vents but it gets hot up there in the summer. We currently have all our stash in our storage unit but that is going to bite the dust before the end of October as a non essential expense.

The bathroom extractor fan pipe runs through the attic space to the outside so we are thinking of splicing into that. I would like a fan fitted up high that has a thermostat on it so it turns on automatically but am looking for advice. Would it be more cost effective to have a switch somewhere in the flat that I turn on as and when. The ideal would be a solar fan but we would be very limited. We can't make any changes to the outside of the building at all but people have satellite dishes up so could possibly have something that size but I know nothing about solar so I am not sure if that would be effective.

I am looking for advice from someone who knows how to do this or has done it. Or if there is a better idea. I can use?

[Yorkshire Andy]

Not only do you need to exhaust you also need to let air in unless you have sofett ventilation

https://laroofrepairs.com/blog/roof-ventilation-system/


You'd need 2 of these and a t piece to use the same duct as the bathroom fan

https://www.amazon.co.uk/Ducting-Connec ... B00FCE0RSE

Add one of these to switch what ever fan takes your fancy

https://www.cef.co.uk/catalogue/product ... BKEALw_wcB

Or

If you can do some subtle modding to the vent pipe if it's out the roof:

https://thargo.com/product/solar-powere ... dQEALw_wcB

[Lemne]

Thanks for that.

With the non return valve, obviously one is in the new section of pipe to the fan but would the other one be between the bathroom extractor and the splice in or between the splice and the outside vent. The last option would be ideal but I cant do anything to the roof, they would have a fit. I am thinking it might be a good idea on the top of our van though.

[cbp125]

I would also invest in insulation to prevent the heat getting into the loft. Foil lined insulation under the tiles will reduce lots of heat in summer and keep you warmer in winter.

I would be a bit concerned about raising the humidity of your loft if you tap into your bathroom vent. That will be carrying very high humidity steam from your baths or showers and needs to be vented to outside or you risk damp or mold

[Yorkshire Andy]

Thanks for that.

With the non return valve, obviously one is in the new section of pipe to the fan but would the other one be between the bathroom extractor and the splice in or between the splice and the outside vent. The last option would be ideal but I cant do anything to the roof, they would have a fit. I am thinking it might be a good idea on the top of our van though.

One
Between bathroom fan and T piece to let it vent out and stop roof fan blowing into bathroom...


Other between loft fan and T piece letting air out but preventing damp bathroom air causing damp in the attic

[Arwen Thebard]

You might try limiting the space you are trying to keep cooler, rather than the whole loft space. If you can create a smaller (vented/insulated) enclave you might find that easier and cheaper.

Some aspects will depend on how old your building is.
Is the floor area boarded out already?
Don't go over overloading the ceiling joists, plasterboard etc.
Take care you dont knock around the roof tiles too much, they dislodge more easily as they get older.