Airbricks End inside extension!

[DanLeMac]

So if you can duct to the outside either in the side wall or the roof then you just need some extractors at the front to draw the air through, is the void under the original living and dining room floors restricted do you know?

Not restricted at all. These old houses seem quite good for access.

 

[DanLeMac]

Defo feels like a plan forming.

Really appreciate the help here.

 

[DanLeMac]

I saw a video where they had 2 of these fans running in a blow and suck configuration.

Could pump fresh air from the rear via ducting and then suck from the front?

Any potential pitfalls to this approach?

 

[freddiemercurystwin]

It has already been suggested that you duct into the rear then extract from the front with suitable extractors.

 

[DanLeMac]

It has already been suggested that you duct into the rear then extract from the front with suitable extractors.

Any ball park figures on cost of labour and parts?

 

[Ivor Windybottom]

Fans really shouldn't be necessary if there's a good enough through-flow of wind. Seems like a waste of money to me, for buying and running them. Also the noise, plus they'll gradually cake up with rubbish and stop working anyway.

But... If you really want to use fans then only extract with them, keep the air pressure negative under the floor. That way, the air will be flowing through any floor draughts from the living space into the floor space. If you blow inwards then you'll create positive pressure, potentially pushing air from the damp smelly subfloor into all the ground floor rooms.

Even just extracting air will make the house cooler so increase heating costs, as it will inevitably pull some warm air from the rooms above.

 

[freddiemercurystwin]

Thing is your asking the air to come in off a floor duct running 90deg to the existing air bricks or down some vertical ducts from above roof level so air will not naturally vent as well as it might do in a conventional cross ventilation situation. Besides those fans are pretty quiet/inexpensive to run, certainly compared to the potential remedial costs of failing to vent the floor properly. For sure they do need maintenance but that's little more than taking the cowl off every so often and clean out with a brush.

 

[Koolpc]

Dig up floors and lay concrete. Problem solved. No more suspended floors that need venting. Assuming it is your forever home.

 

[Ivor Windybottom]

As the neighbours have a heated floor on top of the boards that we already know is not isolated, extracting the air forcefully will also do a pretty good job of sucking all their heat away.

 

[freddiemercurystwin]

Well the OP can open his existing internal vents up to the the open air, either vertically or horizontally and see how things play out, he can always add the mechanical vents later .....