[wffurr]

You already dump waste hot air into your kitchen from the refrigerator during the summer. Is this much different?

It does seem a little silly to have these chains of heat pumps all working in various directions. I read about "cold district heat" in a sibling comment which circulated lukewarm water to use as a heat sink or source with heat pumps. Maybe something similar could be done with a water or refrigerant loop through the house. Probably not economical to do all the plumbing though.

[cucumber3732842]

Everywhere in the country they have basements a huge fraction of them are unheated and probably hover around 38, 40, 35deg in the winter. You dump cold air into that and some % of pipes are going to freeze. And we're talking about a much bigger energy amount, water having high specific heat after all so it is a lot of "cold" being dumped in.

Now, this is of course no concern in the "my water heater is in my attic or attached garage" parts of the country such regulations come from...

[lm28469]

> you already dump waste hot air into your kitchen from the refrigerator during the summer. Is this much different?

Heating water is very energy intensive, fridges are a rounding error compared to water heaters

[bethekidyouwant]

A hot water heater takes much more power than a fridge