zzzzzzzzzz wrote:
On Mon, 08 Mar 2010 12:31:51 -0500, Tony wrote:

Doug Miller wrote:
In article , wrote:
Doug Miller wrote:
In article ,
wrote:
Sam Takoy wrote:
Hi,

Why is cast iron a good material for radiators? Why not another metal?
Would certainly make them a little lighter and easier to deal with.

I would imagine one benefit of a heavy cast iron radiator would
be the mass of metal will hold heat and release it over a long
period of time. I also think that a copper or aluminum radiator
of similar thickness would be prohibitively expensive.
Finally, a correct answer.
I guess majoring in physics wasn't useless after all. *snicker*
Guess not. But, yes, you hit the nail on the head. The principal advantage of
cast iron radiators is that they retain heat very well, which provides a much
more even heat than the aluminum fin-tube radiators do.
The aluminum fin baseboard "radiators" are actually "convectors", not
radiators. Most of the heat from them is cold air going in the bottom
and warm air coming out the top, known as a "convection current". If
you sit in front, 2 feet away, you won't feel the heat on your body like
you do if you sit in front of a radiator. Radiators also have
convection currents but not nearly the same as a convector.

Nope. I this sense they're both "convectors". A "radiator" (without
convection) wouldn't be at all efficient. The source temperature would have
to be much too high.

Yes, heating systems with radiators normally run at higher temps then
convectors. Besides, Google is your friend. Do a search for
"baseboard convectors".

Here is some more for you!

http://www.finehomebuilding.com/how-...ator-heat.aspx

"A: Mark Eatherton, a plumbing and heating contractor in Denver,
Colorado, replies: Radiators and baseboard convectors both depend on hot
water as their heat source. The similarity stops there. As their name
implies, radiators deliver heat in the form of radiant energy. In other
words, the energy from a radiator travels through the air without
heating the air until it strikes a solid object. The object is warmed,
which in turn warms the surrounding air. A radiator’s primary function
is affecting the mean radiant temperature, or the average surface
temperature of the surfaces surrounding your body.

Older style upright cast-iron radiators are usually massive things, with
most weighing a couple of hundred pounds. By their nature, they tend to
radiate energy long after the heat has been shut off. In some cases,
they can cause the room temperature to overshoot by a few degrees, but
their overall comfort is superior to that of their cousins, the
baseboard convectors. Radiators have some convective output, but it is
minimal compared with their overall output potential."