Hi,

I'm trying to source a freezer system and need to estimate the specific heat capacity it must support. How do I calculate the energy (BTUs) and time required to cool down, say water, to a certain temperature, taking into account loss through imperfect insulation?

What is its relationship between the size of the freezer, heat loss through insulation, and the time it will take to reach a steady temperature?

In the end, I need to know whether I've chosen a system of high enough, but not unnecessarily high, capacity for cooling items to about -100C. I have heard that the rate of cooling will not be linear.

Thanks for your help,
Sameer