House air ventilation

sevenhills

How much ventilation does a house need?


I haven't noticed these features in other houses, but in my town house the unused chimney breast has a ventilation brick close to the floor in my room. In the bedrooms there is a plastic vent on the walls, which can can slid open or closed. The vent in the chimney breast maybe the one that loses most heat. Not important in the summer, but my house is cold in winter.
I have no issues with damp.

that

depending on the chimney hole, you could get a football, deflate it, then put it in the hole then expand it with air to block the hole off. Just be weary of condensation in the room now there is less air flow

Robby1988

Air bricks & vents are always there for a reason and blocking them up is never a great idea and is a common cause of damp when problems are being diagnosed.

Older houses aren't generally compatible with our modern day desires to have everything sealed up, so I think you have to be prepared to live with cold from disused chimneys to an extent. The best solution would be to have a draught excluder put into actual chimney, something like this: https://www.chimneysheep.co.uk/. Cheap & easy DIY job if you have means of access & won't cut off air circulation completely.

sevenhills

Robby1988 wrote: »

Air bricks & vents are always there for a reason and blocking them up is never a great idea and is a common cause of damp when problems are being diagnosed.

I am not sure if there is any form of shield on the top of the chimney, to keep the rain out, I must try and look.
If I had the unused chimney removed I might find that my house is warmer. If there is a rain shield, I would need a vent for a chimney breast but not a wall!

Davesnave

Robby1988 wrote: »

Air bricks & vents are always there for a reason and blocking them up is never a great idea and is a common cause of damp when problems are being diagnosed.

Sometimes the diagnosis is that lifestyle plays a major part in determining if there are problems with damp.


Our 1970s bungalow had extra after-market, through the wall vents in all the bedrooms and others in the ceilings of bathroom/shower room. It also had some draughty windows and doors.

The extra vents involved core drilling and obviously weren't done for fun, so it was with some trepidation that we got rid of all of them and put in new doors and windows too as appropriate. Bathrooms got electric extractors.



The result? Nothing, although we're warmer! There's mostly only two of us here and we run a wood burner all winter, but so did the other guys.

Doozergirl

Davesnave wrote: »

Sometimes the diagnosis is that lifestyle plays a major part in determining if there are problems with damp.


Our 1970s bungalow had extra after-market, through the wall vents in all the bedrooms and others in the ceilings of bathroom/shower room. It also had some draughty windows and doors.

The extra vents involved core drilling and obviously weren't done for fun, so it was with some trepidation that we got rid of all of them and put in new doors and windows too as appropriate. Bathrooms got electric extractors.



The result? Nothing, although we're warmer! There's mostly only two of us here and we run a wood burner all winter, but so did the other guys.

That used to be the stock diagnosis over on the house buying board when tenants experienced mould - it's your lifestyle. I appreciate that running a vented tumble drier without a vent is probably going to cause some issues, but if there is mould, then it's really an issue with the building that could be exacerbated by people's lifestyle. We need to treat cause, not symptoms.

The stock solution that seems to go with 'it's your lifestyle' is 'more ventilation' and I'm coming back round to agreement with you here, is that people will go over the top and start drilling massive holes in the house. Often too large and offen making the problem worse, because the walls end up even colder than they were before, which is a magnet for mould.

If the OP is in a terrace then the party walls containing the chimney breasts aren't going to be very cold if both houses are occupied. Ventilation is needed but I think along the lines of Robby above, that some natural insulation (like sheepswool) in the hole, not too tight as to block airflow entirely, will reduce the size of the draught.

Davesnave

Yes, I'm wondering if the holes were drilled pre-cavity insulation and loft insulation too. I'll never know now.


(I'd never have installed cavity insulation here at 500' in an open situation, but the other lot did that and we've had no problem with it at all.)