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Community and Q&A

Dryer Exhaust to “Power” Heat Pump Water Heater?

JohnBovey | Posted in Energy Efficiency and Durability on

Hi there.  We just moved into our newly built house and we have an electric heat pump water heater located about 8 feet away from the dryer. 

Instead of venting the dryer outside, would it be good, bad, or indifferent to vent it in the direction of the heat pump water heater?  The logic is to harvest the dryer heat and convert it into hot water.  Thoughts?

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  1. the74impala | | #1

    Moisture will be a huge problem

  2. JohnBovey | | #2

    Don't electric heat pumps dehumidify the air by default though?

    If it matters, we're in Spokane, WA and it's rarely, if ever, humid.

  3. Expert Member
    NICK KEENAN | | #3

    I see two problems:

    1. The dryer vent gets rid of two things, humidity but also lint. You'd have to come up with a way of collecting the link and keeping it out of the house.

    2. The more significant problem: the dryer and the water heater both run intermittently. This idea would only make sense when both are running at the same time, which you can't guarantee.

  4. this_page_left_blank | | #4

    If these are in an enclosed room, you could harvest a portion of the dryer heat with an air-air heat exchanger. You'd still need to filter the dryer air so it doesn't clog up the heat exchanger, but it solves the intermittent use timing problem. I doubt this would pay itself off in a reasonable time frame, however.

  5. JohnBovey | | #5

    Well crap.... sounded like a good idea on my head. Such a waste to vent heat out of the house when you still then run the furnace to heat the house!

    1. jwasilko | | #6

      When you replace your drier, replace it with a heat pump drier like:

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