On Tue, 15 May 2007 17:37:16 +0100 someone who may be DukeD
wrote this:-

About ten years ago, I installed a central heating for two one-bed
flats in my house. The boiler is in the loft and the flats are
respectively in the ground floor and 1st floor. The only 22mm pipe I
used was the feed and return from the boiler to each of the central
heating circuits. The pipework within each flat's circuit is all 15mm.

I later learned that I should (according to the conventions) have used
22mm pipe for the 'rings' of each circuit too, with 15mm pipe used
only for the short spurs going to and from each rad.

15mm pipe can feed a few normal house sized radiators without great
problem. Beyond that the flow velocity necessary to transport the
necessary amount of heat gives rise to noise.

Conventions tend to be conservative.

I wouldn't do anything to the pipework if changing the boiler.


--
David Hansen, Edinburgh
I will *always* explain revoked encryption keys, unless RIP prevents me
http://www.opsi.gov.uk/acts/acts2000/00023--e.htm#54