[IDK_Melaphystos]

I have been wanting to make a small scale cyclic endothermic cooler for some time know, but just can't seem to figure out how. I thought I'd start with ammonium nitrate and water, but I don't understand the process well enough to know how to take the mixture and restore it to its fundamental parts. Of course, I'm not set on just using ammonium nitrate and water, any endothermic cooling system will work really (I just need something capable of absorbing high amounts of heat). Can anyone help me on this.

 -Thanks in advance

[enahs]

I am guessing you want to try this in solution? Or are you trying for two solids reacting to make another solid?