Gas fire , chimney liner query. Minimum 125mm/5” ?

[sammathias]

I maybe going bonkers( I am getting old) but doesn’t an DFE ( basket)require 100cm of free air?

Noooo I would say a vast majority don't need additional air but some do. I don't tend to fit many mind so could.be wrong

 

[Aire]

I maybe going bonkers( I am getting old) but doesn’t an DFE ( basket)require 100cm of free air?

Yeah I was under the impression a dfe requires 100cm air vent, regardless of advinticious air.

 

[Toby emery]

Yes a DFE fire does need free air as not a clean flame. I’m not getting too involved with it, well I guess I am, I am on a forum asking questions!

Manufacture asked him if he wants a fire which doesn’t require extra ventilation. The house is 200 odd years old and with floorboards as flooring. I wouldn’t trust AA in a new a build.

If the manufacturer doesn’t mention anything then you would go to what the regulations say ?

As said I haven’t got a qualification for fires so don’t know too much about them. The builders opening goes to a gather plate then on top of that is stainless steel tube going to outside through the roof. As said 13” seems overkill when the regulations I’ve read a gas fire must have a minimum diameter flue of 5”.

Even with a 5” flue they are like 20% efficient so with a 13” flue it’s going to be 0% with huge drafts. Like with water you can have too big of a pipe which will produce a linear flow, surely a flue should promote a turbulent flow.

 

[Scott_D]

Hasn’t this type of flue and chimney added lots of cost to the job?

 

[Toby emery]

Yes it has, as said it’s not on my costs. I’m only doing the heating and the gas feeds.

But the client isn’t happy as it is humongous and ugly, and he just asked if I could give advice on whether they need to be that big. One flue run is 5m with 2 45’s the other is maybe 3m straight run.

The builder is adamant and is not going to change them as they are now enclosed and decorated. But client is thinking of ripping it all out and start again and use smaller pipe. I personally would be happy using a 5” pipe as from what I’ve read. But I can’t do the work.

 

[ShaunCorbs]

the manufacture will list something in regards to flueing

 

[Riley]

Contact the manufacturer. Their word is gospel. And seriously ask for the GS qualifications of the builder if he is willing to crack on without

 

[Scott_D]

Get some evidence that you are not involved in fitting the gas fires

 

[Riley]

Good point Yes if you are doing gas runs and the wotsit hits the fan you need to distance yourself

 

[Sharp Point]

Also and I might be having another blonde moment, but doesn’t the height of the gather and size of the opening have to be a certain sizes. I haven’t done one in years, but I feel as if there’s requirements.