[lost_mech_engr]

Hi all,

Unfortunately I have not been in a chemistry class in 3 years and our system will depend on a efficient endothermic reaction.  I am looking for some data on the best chemical reactions that will give us the most energy absorption per weight.  Ideally it would also last for an extended period of time, as this will also be a deciding factor.  This application will be used to cool people, so it will need to be safe.  Also any reference where I could find the data on heat removal would be nice.  The goal is to make cold packs that we can install in our system.

Thanks!

[curiouscat]

Try Ammonium Nitrate + Water

Try the table on this page: http://en.wikipedia.org/wiki/Enthalpy_change_of_solution

[Arkcon]

The phase change from ice to water is particularly efficient and cost-effective.  I know it doesn't sound glamorous like ammonium nitrate and water, but it really does work best.  You'll get the best results if you start with that reaction, and engineer around the shortcomings.