system
Given the following post, respond as if you're commenting on Reddit:
human
Why don't we use freezing to desalinate water?

I am wondering the energy costs of making potable water by heating methods compared to freezing it. 

My line of reasoning is that a byproduct of the cooling would be useful in tropical climates and the final product could be heated by the ambient air before use.

One of the costs of producing potable water with heat is the cost of cooling it before use.
gpt
> One of the costs of producing potable water with heat is the cost of cooling it before use.

Where did you get that idea? You recycle the heat with a counterflow heat exchanger. The outgoing stream heats the incoming one.