alt Hacker NewsHoly crap that re-circulation feature is luxurious!
I'd love to have something like that!
Whenever I take a hot shower I fantasize about putting in a liquid-to-liquid heat exchanger so the hot water can heat up the cold water and you can run the hot water at a much lower temperature.
This application with the bath tub feels way more justified.
Replies
Many people have thought about the drain heat exchanger. However drains need to be way oversized for various reasons and so you can't get good contact with the water: it is mostly air in the drain pipes.
And this is the builder-grade model we got from the house renovation company. There are higher grade ones with fancier stuff...
Presumably you need a bath with extra plumbing? What happens when the heat exchanger gets clogged with soap and hair?
[dead]
That does exist. Simple versions just have a large, deep drain with coils the cold water runs through. Fancier ones have a proper heat exchanger next to the shower (requires a pump) or in the basement. Water sanitation rules probably make it non trivial to get a design certified.