20cm2 Wall vent?

[bster]

I need a through the wall vent to serve an 8.3kw fire, but dont want to use a 70cm2 vent (the smallest draught buster i can find) as only 20cm2 is needed.

any ideas?

BTW - the vent is required as the Corgi reg'd engineer has disconnected the gas supply to a fire in my mates house due to lack of ventilation, and obviously wont reconnect until there is a hole in the wall.

 

[chrishutt]

What do the manufacturer's instructions say is required? The MIs are what you must follow.

 

[bster]

Not sure but isnt it 5cm2 for every Kw over 7kw (net input)?


(meant cm not mm on original post).

 

[chrishutt]

(meant cm not mm on original post).

Yes, I was thinking how ridiculously small a 20mm² hole would be!

Still, worth checking the MIs, especially on newer appliances. Is the 8.3 kW net or gross? If the requirement is for 20cm² then you could drill a line of small holes through a window frame or something. I don't think it has to be a proprietary ventilator.

 

[2face]

maybe a floor vent ?? if the under floor is vented and radion is not a problem in the area .

 

[bster]

Not possible - solid floors.

The main reason for a small vent is that they are worried about the draught - so if a 75cm2 draught buster is used will they feel any draught at all or just a reduced draught?

are combustion ventilators allowed to be positioned at high level to an outside wall from a room?

 

[bster]

i was going to drill a 3" (or whatever size hole) and fix circular grills (soffit vents) but only if the measurements equated to more than the required free air of ...
8.35kw gross/ 1.1 = 7.6net minus 7kw = 0.6kw X 5cm2 = 5cm2

(but I said 20cm2 as i beleive its safer to over specify, this will make up for any **** that may get stuck in\on it etc..)

 

[ollski]

What fire is it bster?, generally manufacturers keep their fires to 7kw to prevent the problem unless its a dfe where you will almost certainly need 100cm2 whatever the input.

 

[2face]

hi level .. but i prefer to place them behind a radiator.

 

[bster]

ollski - I'll check tommorow - its around 7 years+ old and its an LFE inset 8.35kw gross heat input.