What is this air vent for?

paperclap

Hi all,

We've just recently moved into a 1955 bungalow.

We'll soon be having our walls plastered, and want to have a definitive answer for this prior to having them plastered (e.g. do we keep it or block it up?).

We have this air vent which is between the wall joining the living room and conservatory. This is not a typical air brick — it is square, higher and has plastic covers both sides.

Was this added because of the addition of the conservatory? Was it added because of the installation of a wood burner, in an attempt to remove excess build-up of carbon monoxide (long ago, this was a gas fire)? Do we need it at all?

The photo of the white vent / wall is inside the living room. The photo of the brown vent / brick wall is inside the conservatory (sorry for the poor photograph — a shelf was in the way, and couldn't move it!).

It does say "Do not block this vent" on the white vent part.

Any thoughts or advice?

Thank you in advance.

koalakoala

I’ve seen vents on walls when there was a gas fire

paperclap

There previously was a gas fire.

However, I'm assuming that was removed / capped (at the pipe) prior to this conservatory being built. Then again, I could be wrong.

KeithP

I would suggest that the vent was there before the conservatory.

When the conservatory was built, someone, quite reasonably, decided that a white plastic vent would look better on the conservatory side of the wall.

paperclap

So, with that in mind, are you suggesting that this vent was for the sake of removing excess carbon monoxide when the previous gas fire was in use?

I can't imagine it is a simple vent to "air the house", as, why not use a simple air brick like the rest of the house has?

stuart45

Vents are put into walls to allow oxygen into a room if there is a fire in there which requires it. It's not to remove carbon monoxide as this should be going up the flue.

EssexExile

Gas fires over a certain power require vents to the outside. It appears that you don't have a gas fire and the vent doesn't go to the outside. 

Do you have a wood burner? I don't know if they require vents, I suspect they do, but a vent that doesn't go outside is pointless. I'd block it off but check if I need a proper vent to the outside somewhere else.

paperclap

We've a wood burner, yes. Though, not sure if they do require ventilation.

EssexExile said:

Gas fires over a certain power require vents to the outside. It appears that you don't have a gas fire and the vent doesn't go to the outside. 

Do you have a wood burner? I don't know if they require vents, I suspect they do, but a vent that doesn't go outside is pointless. I'd block it off but check if I need a proper vent to the outside somewhere else.

That was my exact thinking! That is why I'm so stumped by it!

stuart45

Wood burners need ventilation, the amount depends on their size, or they can suffer from air starvation.
You can vent from another room as long as that room is vented.
Stove room ventilation, UK stove building regulations, document J (stovesonline.co.uk)

paperclap

Our wood burner is a Clearview Pioneer 400. It is advertised as 1kW-5kW, so perhaps it does need ventilation?

I've read that if your house was built pre-2008, and if the wood burner is 5kW or higher, you should have ventilation.

But, as EssexExile pointed out, the ventilation seems almost pointless, as it isn't on an external wall — it simply leads from one room to another (living room to conservatory).

stuart45

You need a vent in the connie for the vent in the wall to be effective, unless it leaks a lot already.