On 10/11/2011 22:52, Lieutenant Scott wrote:

Why are they called radiators when they are primarily convectors?

ISTR that it is roughly even stephen but can't remember whether the
information relates to modern panel radiators or the old fashioned
monster cast iron ones which were the original radiators.

Probably the old ones. You can test yourself, just see how much hot air
is flowing up form the modern ones (there's a reason for that concertina
stuff inside). And you can't feel anywhere near as much being radiated.
Mind you it might help if they were black, but then you'd need brighter
lights,

Probably, but possibly just finless. The radiator I am sitting next to
is a single panel with no fins. Fins make a substantial difference -
about 42% greater output according to one site I checked.

I've never seen a finless one, what a strange idea! Even my slimline
single panel hall radiator has fins at the back.

This house had central heating fitted in about 1975, 3 years before I
moved in. No fins on any of the original radiators. I have a catalogue
which I think dates to the early 1980s (gas fired CH boilers from £75)
with not a single finned rad in sight except for Finrad skirting
radiators which was referred to as "this new concept". The section on
'Comfort' ends with:
"For these reasons perimeter skirting radiators provide fullest comfort
at lower air temperatures then are required by other forms of central
heating which have less efficient heat distribution. Even on the coldest
days there is no need to set the thermostat in the 70s to feel warm;
with perimeter skirting radiators the mid 60's produce that healthy
sense of comfort, at a present to breathe air temperatures."

For those to whom Fahrenheit is a foreign language 70F is 21.1C and 65F
is 18.3C.

--
Roger Chapman