On Sun, 14 Nov 2004 12:25:13 +0000, Simon Hawthorne
wrote:

Hi all

Just finished the job I started last week - fitting a TRV to one of my
radiators on my microbore system. Actually removed the rad yesterday,
flushed it out with a hosepipe- then cleaned the threads for the
valves with a toothbrush - used '5 turns' of tape on the valve threads
- and reconnected. Dry as a bone now!

Anyway, I would like to add another rad to the downstairs circuit. As
far as I can see, the circuit of fed on a 22mm pipe from the boiler to
a manifold - where lots of 8mm pipe branches off the the rads. The
retur pipes are the same. To add another rad, can I simply but an
equal T joint into one of the micorbore feeds, and the same on the
return? If I do it on the feed to the closest existing radiator, will
it work?

I understand that there would be a temperature drop in the existing
rad, but that is the one I have fitted a TRV to - because the room
gets very warm - so shouldn't be a problem. I only want to run about
4m of pipe from it - and put on a small new rad in a corner of the
kitchen that is about 18 feet from the nearest other rad - and gets
quite cool...

Thanks in advance

Simon

It depends on the radiator sizings, Simon. Over a few metres, 8mm
tube will support 1500W. So take a look at the sizing and calculate
the rating of the existing radiator. Obviously if the room is
getting very warm some under-running may be OK. There would be some
interaction between the radiator behaviours if you tap off near the
first radiator, less if you tap off nearer the manifold.
As long as you're not trying to get more than about 2kW or so in total
it should be reasonable, albeit it not ideal

It would be better to plumb back to the 22mm.


--

..andy

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