On Sun, 13 Mar 2005 19:13:14 +0000, Andy Hall wrote:

Do bear in mind that any of these enclosures reduce the heat output
compared with the native rating. For a conventional radiator in a
cabinet with air gaps and grille front, it can be as much as 30%.

All of this, plus the derating to 90% for water temperature, need to
be included when sizing. However, if you can have long runs, then it
should work.

Of course, all this is for an additional radiator. I'm not planning to
remove the exisitng one, rather I was thinking of setting its TRV to a
lower level than the new one. So when the system first come on both run
at first to get up to temperature, but overnight only the new one will
run to keep the room up to temperature (this is the room with the
thermostat for the upstairs zone in).

Many thanks to all for your thoughts. I see I can get 30cm high
radiators from stelrad at up to 3m long (the high output version of
which is 3Kw - a lot more than my pipework suggestion would even have
delivered). So seeing if I can mount one of those on slightly longer
brackets is my current thinking. Truely several heads are better than
one.
--
On-line canal route planner: http://www.canalplan.org.uk

(Waterways World site of the month, April 2001)