I have seen a heat storing product that is essentially waterwith it's melting point
 

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!



"Ice 9", from the book _Cat's Cradle_. HTH :-)

Bob

I have seen a heat storing product that is essentially water with it's melting point
 

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!

I have seen a heat storing product that is essentially waterwith it's melting point
 

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

I have seen a heat storing product that is essentially waterwith it's melting point
 

zxcvbob wrote:
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!



"Ice 9", from the book _Cat's Cradle_. HTH :-)

Bob

Well that ought to confuse a lot of people!

Sounds like part of the thermodynamic laws.... A quick search of wikipedia found what I was looking for.... van der Waals (see first link), a modification of the Ideal Gas Law (second link) which is pV = nRT.

In essence, pressure change will determine vaporization points, and therefore the ammount of heat that can be stored.
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http://www.keengardener.co.uk/