Peter HoseyMar 2

I had an idea: What if the exhaust heat from an air conditioner could be captured in water to be stored in the hot water tank?

Apparently this exists and is called a heat recovery system: https://parts.rheem.com/product/RPD-96612/heat-recovery-unit-r-410a-r6k-410

Show threadPeter Hosey

I've mentioned offline that one of the things LLMs are good for is solving the “tip of the tongue problem”—where you can describe a thing but don't know or can't think of the name for it—and that happened here.

I searched “air conditioner that heats water” and the “AI Overview” mentioned the term “heat recovery unit”.

Of course, I don't take the word of the “you should glue cheese to your pizza” bot for anything so then I searched the proposed term to find a source to confirm that it's real.

Mar 2 at 6:36amIvory for iOS
Show threadJim ReaMar 2
@boredzo Are you saying that I shouldn’t glue cheese to my pizza? 🤯
Show threadJmelloyMar 2
@boredzo I’ve always found combined heat and power units cool too, they’re basically generators on the back or your furnace.
Show threadPeter HoseyMar 2
@Jmelloy Oh, that is neat. Probably helps the longevity of the furnace, too, since turning otherwise-waste heat into electricity would effectively help cool the furnace closet.
Show threadJmelloyMar 3

@boredzo although modern furnaces already do a second loop through the heat exchanger, and it bleeds enough heat the exhaust gas partially condenses to water. Last winter we had a cold snap and the furnace worked fine but the water drain line froze.

I wonder if one of the reasons chp hasn’t really caught on is it’s not terribly efficient.