Can a chimney breast be used for external ventilation for gas fire?

[SJRSJR]

Hello. I'd like to get a Decorative Fuel Effect fire with a rating over 6.9 kw but I understand that the room will need additional ventilation. Can I use a second, separate, disused chimney breast in the same room for the vent or does it have to go directly outside? The breast currently has a couple of bricks missing so I hoped I could calculate the free air volume needed and install the right vent size. Also, the chimney is clapped with a C Cap for ventilation but I don't know the free air volume of that. Any advice? Thanks.

 

[footprints]

Ventilation should be direct to outside.
Trying to pull air down a chimney while the house is being warmed and hot air will be rising up the chimney is not going to work well anyway.

 

[SJRSJR]

Thanks. So would an air vent through the floor to a deep cavity which runs under the entire house and is ventilated front and back to the outside be acceptable?

 

[muggles]

Provided it has been correctly sized and installed, yes. Why don't you want to go directly to outside through a wall?

 

[SJRSJR]

Thanks for the reply. There's a huge amount of natural ventilation already - open plan, draughty etc so I don't want to start knocking holes in walls but I am getting a wooden floor installed so could incorporate a vent. So there are no circumstances where a chimney breast vent could be used?

 

[muggles]

No

 

[FiremanT]

Thanks. So would an air vent through the floor to a deep cavity which runs under the entire house and is ventilated front and back to the outside be acceptable?

It can be ducted from the floor to outside.

If no duct, there must be NO communication under floor to a neighbouring property.The existing vents are probably terracotta, and are nearly always too small. you have to measure the smallest cross sectional area of the holes. A device is available to help with this.

You absolutely cannot use the old chimney as a vent, as you cannot guarantee it will be working in the right direction, as per (?) footprints

 

[dilalio]

Op: your installer will handle all of this and advise you to the particular requirements of your individual case... it is not a one size fits all scenario... there are clear guidelines but these can be satisfied in many different ways according to install site conditions.

 

[FiremanT]

Hello. I'd like to get a Decorative Fuel Effect fire with a rating over 6.9 kw but I understand that the room will need additional ventilation. Can I use a second, separate, disused chimney breast in the same room for the vent or does it have to go directly outside? The breast currently has a couple of bricks missing so I hoped I could calculate the free air volume needed and install the right vent size. Also, the chimney is clapped with a C Cap for ventilation but I don't know the free air volume of that. Any advice? Thanks.

What fire are you considering?