These is all good info. but new to these.Just got some nice frogs from Keith at Frog Brothel. he had phase 22 panels in the box. the card broad was pretty cold but frogs and inside ,seemed about the same temp as my house. the panels where not cold ,not warm. How do they work? dealt allot with coral/fish shipping, they got the same goal in mined 85. but that was done with heat packs and water. oh' ya do I save the panels.thanks Jeremy
Well, you can check cryopacks website for a detailed description, but long and short of it is that they are a product that changes state much like water, but it's freezing point is in the lower 70's. I takes energy to heat something, but it takes even more energy to make that something actually change state. The gel packs act as a heat sink, like any other cold pack, but one in which the phase change further retards the heating or cooling process of the surrounding area.
So, if the shipping temps are below the freezing point of phase 22, I heat the packs up to a liquid form before shipping. If the shipping temps are above the freezing point of phase 22, I lower the temps so that the packs are solid. That way, the ambient temps have to actually change the state of the packs before they can start increasing or decreasing in the box.
At least that's my understanding of it.