Gas flow rate measurement

[StanHerbert]

Firstly - I'm not going to be doing any gas work myself - just trying to make sure I know a bit about this before getting quotes.

I'm keen to get a combi boiler installed in our airing cupboard. There is an existing gas supply here, but the pipe work is hidden under the concrete floors for most of it's length, so it's sizing between the gas meter end (where it's 1 3/8") and the airing cupboard (where it's 7/8") is unknown.

Is there any way of testing the gas flow / pressure available to see if it will be able to support a fairly large boiler (something like a Vaillant 837)?

If we can avoid running a new supply this would be enormously preferable as the pipe length from one end to the other is about 15m and there isn't an obvious route available.

Look forward to your replies.

 

[Crezzer]

That would be 1" and 1/2" pipework, an 837 consumes about 3.5m3 from memory, your existing pipework wont be big enough.

 

[onlyfitidealboilers]

Re pipe required I speak from experience when fitting that blr.

 

[Agile]

Stan ( or Herbert? )

Your selected gas registered installer should be able to advise you.

Quoting a length like 1" means nothing if you dont define what measures 1" !

A clever installer would often be able to estimate the gas flow resistance but its almost certain to need an upgraded gas supply in at least 28 mm.

Tony

 

[StanHerbert]

Thanks for the replies - looks like we'll probably need a new supply then.

Tony apologies, I should have been clearer, the measurements given refer to the outside diameter of the black iron pipework visible at each end. I presume your reference to 28mm is the diameter of the standard soft copper pipe of that size

What are peoples views on chopping a 28mm (or more) notch out of 8" x 2" joists along the entire length of the landing? Or would it be better to take the new supply up to the loft, across the house and drop down into the airing cupboard? This would result in a longer length of pipe - approx. 15m along landing or 20m via loft.

 

[Agile]

It is up to you to decide where you want the pipe to go.

If the pipe is longer then it will probably need to be partly in a larger size than 28mm. Not a big problem if thats in the loft.

Notching depends on the position and span of the joist.

Tony