Several buildings seem to accidentally destroy heat

It appears that there are several buildings which can destroy heat as a side effect of their operation.  I'm not talking about the "magic" buildings that provide a cold sink (Wheezewort, Thermo Nullifier, etc): the one I've noticed is Water Filter, and there might be others.  I found this to be really frustrating when I learned about it, because it makes no internal sense in the context of the game.

The specific issue is that Water Filter's output is a flat 40 degrees Celsius regardless of the heat of the input liquid.  This means that by allowing water to absorb heat before filtering it, you can destroy heat -- if you can get to near boiling, I imagine you can destroy quite a bit of heat.