Worcester 25/32Kw pipe sizes

[billy_smith]

I've got the above oil fired combi to fit, The house requires 29Kw of heat.

The guy I'm working for has suppplied all the material and I noticed today that all the copper is 22mm for the main flow and return legs.

Now whilst looking at the boiler the heating connections are 28mm, Will 22mm copper supply 29kw of rads, I've had conflicting opinions and personally myself I think it will struggle.

The boiler is being fitted in an out building with approx 6M run into the main building, Would it suffice running 28mm from the boiler in the out building to where the pipes enter the house and then run the flow returns in 22mm copper.

The upstairs and down stair circuits will be tee'd off seperately in the out building so the downstairs will have a 28mm feed and the upsatirs will also have 28mm feed but again this will reduce to 22mm copper where it enters the main building.

Any pointers would be ideal.

 

[dcawkwell]

I would run 28mm until the pipe splits to go upstairs and downstairs or
separates to different sections of the house.
Run the floors in 22mm.
Job done.

 

[billy_smith]

Magic, Thanks for that.

That was how I was trying to expalin it !

Am I correct in saying 10mm will carry 4kw of heat also ?

 

[dcawkwell]

Magic, Thanks for that.

That was how I was trying to expalin it !

Am I correct in saying 10mm will carry 4kw of heat also ?

For a quality job wouldn't consider 10mm.
But don't see why it wouldn't be ok.

 

[billy_smith]

It's an old farm house I'm doing and it would be a mare to try and pipe the lot with 15mm copper.

I'll run the flow/returns in 22mm as far as possible then 10mm from there.

Got a few big rads going in IE 700x2000 and I was concerned about the ability of 10mm being able to heat this.