Radiator Circuit Design

[Rapide]

Hi All,

I am planning the new installation of radiators in my stone cottage (getting rid of the night storage heaters at last -yippee ). The cottage is only 4 metres wide and is like 2 railway carriages one on top the other; 3 rooms downstairs and 4 smaller ones upstairs - all in a straight line.

I plan to use one long 22mm feed and one 22mm return pipe from the boiler going in a straight horizontal line from one end of the cottage to the other - at floor level upstairs. The boiler (not selected yet but likely to be a Trianco or Worcester condensing oil boiler near the top end of the price range) will be downstairs teeing into the centre of the 22mm feed/return pipe-runs.

Rather than a circuit of radiators in series, I plan to tee each one (15mm) individually from/to the 22mm feed/return for both the upstairs and downstairs rads. Much like a fishbone I guess. (For reasons I won't bore you with, it will make life much easier this way).

My question is this: given this unorthodox layout, am I likely to have problems with balancing the radiators in due course, or any other unforeseen problems? If so, what would the experts suggest?

Thank you in anticipation.

'Rapide'

 

[D_Hailsham]

I plan to use one long 22mm feed and one 22mm return pipe from the boiler going in a straight horizontal line from one end of the cottage to the other - at floor level upstairs. The boiler will be downstairs teeing into the centre of the 22mm feed/return pipe-runs.

Rather than a circuit of radiators in series, I plan to tee each one (15mm) individually from/to the 22mm feed/return for both the upstairs and downstairs rads.

In a two pipe system the radiators are in parallel not in series, so I don't see what your problem is. A drawing of what you have in mind would be helpful. You can create one using Paint and then upload to your image folder.

 

[Agile]

Hi All,

Rather than a circuit of radiators in series, I plan to tee each one (15mm) individually from/to the 22mm feed/return

As you were not aware of how heating circuits are normally configured it might be better if you employ professional assistance with the design as you will presumably be using a CORGI installer for the gas boiler anyway.

Tony Glazier

 

[kevplumb]

The boiler (not selected yet but likely to be a Trianco or Worcester condensing oil boiler near the top end of the price range)

cmon tony

 

[wilhelm]

nowt wrong with these boilers

I know which make I would go for.

 

[Bon]

As Agile says, it may be better to let someone have a look at your proposed layout.

What you're proposing isn't that out of the ordinary, but you need to ensure that the pipework is of adequate size througout the system to get the required amount of water and therefore heat to each rad. Assuming that 22mm to/from the boiler will be sufficient is not entirely correct.

Start with the furthest rad from the boiler on the circuit and work backwards adding up all the flow rates. This will ensure that all rads get enough water

 

[Rapide]

Thanks for all the replies - and so quickly! I clearly need to explain myself a little better, and yes I did mean parallel and not series - and a 2 pipe sealed system!

I have uploaded a picture, much simplified and done as suggested in 'Paint'. (All valves and DHW have been left out of course). The downstairs rads will be vertically below the main feed/return pipe upstairs and about 2.5 to 3 metres from it. Most of the upstairs rads will sit right on the main feed/return. So my question is:- will there likely be insurmountable balancing issues with this plan?

The aim is to minimise downstairs pipework:
a. because the wife doesn't like it.
b. because it will reduce significantly the number of holes I have to drill through solid stone walls 500mm thick in this 400 year old cottage!

I take the point about checking flow-rates to ensure optimum pipe sizes; thanks Bon.

Rapide

View media item 475

 

[D_Hailsham]

The downstairs rads will be vertically below the main feed/return pipe upstairs and about 2.5 to 3 metres from it. Most of the upstairs rads will sit right on the main feed/return. So my question is:- will there likely be insurmountable balancing issues with this plan?

I take the point about checking flow-rates to ensure optimum pipe sizes

So much easier to comment when you have a picture
Balancing should not be a problem provided the system has been properly designed. That means: calculating the heat loss from each room; installing the correct sized radiators; installing the correct sized pipe work in each section; calculating the index circuit; installing the correct sized pump.

The only problem I can see is that there are two distinct branches, left and right of the boiler so ensuring that each branch gets its fair share could be a problem. One way of doing this would be to put balancing valves in the main feed to each half.

 

[Bon]

I can't see a problem with that layout. Provided all the pipework is sized correctly and all the rads are fitted with lock shield valves, balancing shouldn't be an issue.

You go really OTT and fit commissioning sets to the two branches that split from the main boiler flow and return to ensure that the divde between the left and right sides of the circuits are set up correctly, but that would be over-kill on a system that size!!

 

[Rapide]

Thank you to D Hailsham and Bon for the most helpful of replies.

Rapide