Central Heating Pipe Sizing

[garygvl]

Yes I understand that, but I don’t think the op’s description of knocking two houses into one, will be new builds lol...but I maybe wrong.

you asked was it old or new build just making a comment about new builds
edit.. by the way agree an estimate of 13k heat load for a conversion of two 3 beds into one 4 bed is low without a s..t load of insulation

 

[SimonG]

Sized appropriately. Or pay somebody to do it.

 

[***Tom11***]

Apart from the recommended book from Chris above,

What methods do people recommend to calculate heat required then ?

One of the rooms in the property is as follows:
Dining room
4.6m (L)
3.8m(w)
2.3m(h)
Solid floor
heated rooms above
no windows
2 external walls
Cavity walls - dont think insulated.
Probly built in the 70's
App gave me 1400w

I have always used the Anton app before and has always seemed fine, no complaints. But as this is quite a large property i thought id get some advice from engineers with more experience.

 

[ShaunCorbs]

1.25kw estimated

About an 80x60 k2

 

[Aire]

First off, whats going in the bathrooms? Is it 2 full bathrooms with baths and showers etc or one bathroom and one ensuite? You need to answer these questions and decide whether a combi is suited, she might be demanding a combi but it's your head if it doesn't work. Also what's her mains flow rate like? If you are installing a high flow, your going to want at least 20litres a minute coming through the mains. If your converting 2 houses are you going to utilise both incoming mains? One for the hot and one for the cold supplies? As for your heating, 13kw isnt excessive so if it's sized correctly 22mm will be fine.

 

[***Tom11***]

Hi Craig,
1 bathroom, 1 shower room although this could well end up being 2 baths with showers over.
A Combi is not going to be suited for this situation as i have made this clear but at the end of the day shes paying and if she continues to insist on a combi, all i can do is give my opinion.
Only 1 of the CWM will be used as far as i have been told. It has a 22mm incoming main with easy 20LPM.

Its more the radiator sizing i keep getting conflicing answers on so was looking for advice on this to make sure i get the right Flow/Rtn pipe sizes and boiler size correct.

 

[SJB060685]

Buy a copy of R.D Treloar, it will guide you through the calculations, plus a whole lot more

 

[Aire]

Ok fair enough, I would get it in writing though that you have advised against a combi and will not be held responsible if it doesn't work as desired. Boiler size with a combi, your only sizing that on the hot water flow rate as it will be more than adequate for the heating. If you can convince her to go system then 20kw will be fine based on what you've said. Are you repiping the whole system? If so I would zone upstairs and downstairs separately and 22mm will be fine, like Shaun said in the first post.

 

[chris watkins]

Apart from the recommended book from Chris above,

What methods do people recommend to calculate heat required then ?

One of the rooms in the property is as follows:
Dining room
4.6m (L)
3.8m(w)
2.3m(h)
Solid floor
heated rooms above
no windows
2 external walls
Cavity walls - dont think insulated.
Probly built in the 70's
App gave me 1400w

I have always used the Anton app before and has always seemed fine, no complaints. But as this is quite a large property i thought id get some advice from engineers with more experience.

I have always used either Stelrad Stars or the Myson version as they also correct for the Delta T when selecting for rads do these App based ones ?? Both could were saved or could be printed to show what had been done.

 

[***Tom11***]

I signed up to use the stelrad stars ealier. It let me start a project but when i filled in the initial page and pressed continue it kept saying a message, cant remember now, something like cant save project so ive emailed them to ask why, not looked at the myson 1.
Its mad how far out results i got using 3 different methods, the multiply- floor area x type of room, an app based sizer and bisque calculator.