I want to add an additional radiator to a loft converted to a bedroom.
I think the radiator fitted is just about adequate for the room, but:
a) SHMBO likes her bedrooms about 10 degrees hotter than I do
b) the radiator (which is on the only vertical wall in the room) is
behind where we have the bed-head, so it's hard for the air to get out,
and the bed tends to push up against it, boiling my head in the night.

Along one side of the room is a suitable surface for putting a long,
thin, radiator - it's about 4 metres long but only about 20cm wide.
I've got easy access to the heating pipes at either or both ends of it.

From my canal boat experiences, I know about "finrad" - a copper tube
with thin metal squares attached to it, which is very efficient but
looks nasty, cuts you if you brush against it, and collects more dust
than a dyson.

A prolonged google has only turned up some "designer" radiators, but at
400quid a metre, this is more than I really want to spend - by at least
one order of magnitude.

Currently my thoughts are running to a loop of chrome tube, on chrome
stand-offs, so I end up with about an 8 metre run, with feed at return
at the same end. But the joints are going to have to be compression and
will look a bit nasty with 6 inline couplers as well as the elbows at
the end.

How much heat is this likely to give out?
Will 22mm tube work better than 15mm (greater surface area)?
Can anyone think of anything better at a sensible price?
Or any improvements to the idea?
--
On-line canal route planner: http://www.canalplan.org.uk

(Waterways World site of the month, April 2001)