• Rivalarrival@lemmy.today
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    11 months ago

    I’ve contemplated a heat exchanger on the tub drain line to capture the heat from my shower to preheat water into the tank.

    A small, non-functional gas water heater, located in a hot, summer attic, and with a small fan blowing air down the exhaust stack, makes an excellent pre-heater.

    Stick a small window air conditioner in there, and it becomes a redneck heat pump water heater.