Gas Fire with HRV

Jill

Hi

Has anyone out there installed a gas fire with a Heat recovery system. We have used an airtight membrane on our house and have installed a heat recovery system - we had two chimneys and I want to put in a gas stove in one and a gas fire - glass front in the other. Getting conflicting advice on whether this is ok.

Any advice appreciated

Thansk

Bogtrotter1

Hi,
ok, I think, if roomsealed type of appliances, ie draw their combustion air from outside
D

heinbloed

I don't agree with Bogtrotter1. If the fire is roomsealed and has it's own independant airsupply and both are well maintained (by a trained gas fitter at least once per year)then you won't have a problem. But make sure that there IS NOT a Heat Recovery Ventilation Unit installed. This would indeed give problems in case the room sealing of the fire isn't working properly.There are devices available for about €1,000 meassuring permanently the pressure differences. If a set difference is not kept or exceeded then this device will automatically switch-off the gas fire or the HRV or both.But I haven't seen them here in Ireland, they're new on the continental market as well.

Jill

Thanks for that - we do have a heat recovery unit but have received advice from an installer that it is ok to use the fire with a conventional flue - apparantly the particular fire does not draw sufficient air from the room to require a special vent and should be fine

Bogtrotter1

Hi,
Ok, I gave a very quick reply before i went to work, i agree with heinbloed, that, all appliances must be fitted and maintained by competent persons (GIS,GID) using appropriat test equipment. (This will be a legal requirment very soon)
And a decloration of conformity from the fitter.
I may be mistaken, but, in my 2002 I.S.813, nowhere does it say you cannot use HRV with a roomsealed appliance.
The final answer will be in manufacturers installation instructions, if in any doubt, contact them first.
D

Bogtrotter1

Hi Jill,
I was drafting my reply when you replied, I would still recomend looking at roomsealed appliances to get a good BER.
D

heinbloed

Forgiven, Bogtrotter(smiley), we're still kickin'.
The manufacturer usually keeps his specifications as broadly aplyable as possible, to secure a large market.He certainly can't foresee to which conditions his open or closed fire will be exposed when finally installed. A large room holding many persons or with a high air pollution will have a larger airexchange by the HRVU then a small standard room with for example only one non-smoker sitting in it reading a book.Therefore a generalisation like one-fits-all can't be accepted by the responsible builder.
What matters are test results, tested in-situ, in life situations by a proper installer. With a good lee to make up for the unforeseen accident.(What happens if several inlets and outlets of the HRVU are closed/blocked and the entire pumping load is aplied to the one room with the fireplace?)
Differential alarms sensing differing airpressures and giving off a signal or switching off the apliances are common standard in modern room sealed boilers.They have to be there by law as a safety meassure.Why not with sealed fire places one wonders.

copper12

An open gas fire will need an open air vent both high and low vents. These vents will have to be permanently open and cannot be obstructed .
where the house has’ had work done ;where by all or as much as passable; air leaks have been sealed .
Then a fire with a balanced flu would your best option