feradejack wrote:
I have seen this on a BBC programme called "Tomorrow's World" back in
the late 70's or early 80's.
I saw it first used as the contents of a storage heater to be used in a
Truck (for when the driver sleeps in the cabin).
I saw it later as a row of gallon containers in a greenhouse to help
keep the internal temperature constant.
I believe that the melting point was raised to over 20 degrees celcius
(70 F) and maybe quite a lot higher.
If you have any idea what this stuff is, I would like to know!





Do a Google search for "phase change heat storage" (without the quotes) and
then be prepared to read a lot. Remembering a great deal from your early
physics and chemistry classes will be useful.

One example:

http://www.ces.purdue.edu/extmedia/ae/ae-89.html

The first chemical they mention is "Glauber's salt" and with that I'll
leave you to your research...

--
John McGaw
[Knoxville, TN, USA]
http://johnmcgaw.com