One pipe system ...help/advice

[chestercity]

I have a one pipe system on a Ideal Mexico2 boiler. Works well and is serviced by BG as prior owners did so seemed good to continue.
I need to add rads x 2 as there are areas that require greater output.
I can work under suspended timber/block floor and need to knock through block work to install.
Can I 'T' off to a radiator I add with a run of approx 1 meter from the 22mm using 15mm pipe?
Or do I have to run the 22 mm pipe nearer the new rads? I am assuming flow will be impaired on 15mm pipe on this system?
Any help much appreciated!

 

[denso13]

I wouldn't tee of a supply to another radiator on a one pipe system. However, if the system is working well at the moment you may find whatever you do has a detrimental effect.

 

[chestercity]

Thanks for your response.
However there must be a calculation as to how many rads a system can take, depending on size and output of rads, length of run and pipework? And of course the boiler. Also I can see that one rad has been added at some point and works fine.

 

[denso13]

It may well work by adding extra rads but it was just a general comment. One pipe systems can be difficult to set up and I don't think anyone can say do x,y, and z and it'll work fine.

 

[chestercity]

Thanks but there will be a way forward I am sure. There is a science to heating, as opposed to a try and see approach...