Solid fuel ventilation sizing

Irish Steve

Have an interesting issue that I need to make sure has been correctly dealt with before I finish the job I'm doing for a good friend of mine. I'm installing network cable connection points in their main living room to make it easier for them to use things like laptop computers with their TV, and to make it possible to use wired access to the internet rather than rely on (slower) WiFi. That's meaning some considerable chasing out of cable tracks in the walls to put the connection points in the right places.

So, that's the background, and part of the reason why they are about to redecorate their main lounge/dining area, they are also putting in a new wood laminate floor, and new skirtings, so there will no longer be air leaks through the existing floor boards and skirtings from the under floor void.

Another part of the redecoration exercise will be to get rid of 3 very untidy and no longer used 12 x 8 air vents that were part of a hot air heating system, which was based on a unit in a cupboard next to the lounge. That system was removed a long time ago, and replaced with a traditional radiator based kerosene fired oil boiler with conventional flue.

The issue I'm concerned with relates to solid fuel fire ventilation in that if these 3 redundant vents are blocked up, I'm not happy about the size of the one remaining vent into the room, as that external vent appears to have at some time been "modified" by someone (previous to the present owners) to reduce its size, and I'm not sure that it's large enough on it's own to allow an adequate air flow into the room. The reason I'm concerned is because it's clear from the dust and airflow marks that air is coming into the lounge through the old heating vents from the old hot air heating cupboard. If those vents are no longer there, then the only vent in to the lounge is the external wall vent, and as I mentioned above, it appears to have been size reduced at some point, and I'm not happy that is is now large enough on its own for the solid fuel fire.

I think that it's better to remove the old vents, as they are drawing air from the boiler space, which I don't think is ideal, as that boiler is not room sealed, so I'd be happier to see it isolated from the living space. Having found out what the layout is, I am also going to check the boiler space to make sure that it is getting adequate free air, I am hoping I will find an under floor air vent, as the boiler space doesn't have an external wall, so there's no facility for an air vent to outside through a wall as such.

So, taking things one step at a time, what's the minimum cross sectional area for an external air vent for a room with a traditional solid fuel fire. There's no back boiler or other enhancements, it's just a "normal" open hearth solid fuel fire.

There are no issues at the moment, they have a CO detector in the lounge, but I want to be 100% sure that the planned changes are not going to cause any issues with either the solid fuel fire or the oil boiler.

Thanks

Steve

esox28

http://www.solidfuel.co.uk/pdfs/carbon_monoxide_guidance.pdf

10,000mm2 or 4" diameter would be sufficient for a stove 20kw or less.

Billy Bunting

esox28 wrote: »

http://www.solidfuel.co.uk/pdfs/carbon_monoxide_guidance.pdf

10,000mm2 or 4" diameter would be sufficient for a stove 20kw or less.

Does the square peg fit the round hole

esox28

Billy Bunting wrote: »

Does the square peg fit the round hole

verifying the sum of two sides by the sum of a fook it your probably right Billy. Only thing my hilti te76 doesn't do square.

Irish Steve

Thanks guys,

Looks like if I just get rid of the extra mortar that someone threw into the bottom of the original vent and reduced it by 50%, the restored airflow capability will be OK.

Steve