Use defunct gas fire cowl for MEV

KungPao

Hi,

I'm planning to install an MEV system soon in my 2 storey house. I’ll be doing the ducting and I’ll get a spark in for connection.

Just wondering about the exhaust duct. Rather than get a roofer in and get a new vented tile and blowing another few hundred, I’m thinking of hooking it up to an unused aluminium chimney stack from a long gone gas fire. The stack is just there doing nothing with some ducting dangling down in the attic.

The cowl look like this https://www.amazon.co.uk/AirTech-UK-Cowl-150mm-Woodburner-Ventilation/dp/B0C1X6RP1F/ref=asc_df_B0C1X6RP1F/?tag=googshopuk-21&linkCode=df0&hvadid=641648879743&hvpos=&hvnetw=g&hvrand=7230913157309260977&hvpone=&hvptwo=&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=1007850&hvtargid=pla-2196211663160&psc=1

The only issue I can think of is wind messing with the flow out, but then again if that was issue wouldn’t it have been unsafe for a gas fire in the first place with CO potentially being blown back down?

Or also maybe vapour condensing and dripping down, but maybe as it’s warm air always passing out this would warm the aluminium enough to stop this?

Any help appreciated!

10-10-20

Hi! I would not be recommending this method, as you rightly pointed out you would accumulate condensation on the inner wall of the stainless-steel (rather than aluminum) flue and this would lead to other issues. The vented heat would not be sufficient to warm the flue at all. Best stick to the cowl which is designed for that function.

KungPao

Thanks! Yeah I was on the fence about it. I do have a roof vent (duct hanging down from it and going nowhere in particular) right beside this ex-chimney stack. I might just use that, the old chimney stack can take over its duties I think.