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Should I add more insulation on my heat-pump water heater?

Bozothec | Posted in Energy Efficiency and Durability on

I have a Stiebel Eltron Accelara 300 HPWH. It is in a basement in New England and the basement stays between 55- 65 degrees year round. Can I add additional hot water heater insulation sleeve and will it make a difference?

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  1. user-2310254 | | #1

    What does Stiebel say? At a minimum, I would want to know if adding insulation would void the warranty.

  2. GBA Editor
    Martin Holladay | | #2

    I imagine that you can add an insulation blanket if you want, as long as you are careful to ensure that the blanket doesn't cover any access panels, air intake openings, or exhaust air openings.

    That said, I doubt whether you will see significant energy savings from this measure. Stiebel Eltron brags (somewhat vaguely, I admit), "We super-insulate our tanks, because minimizing stand-by losses means less energy is wasted. For maximum energy savings it makes no sense to skimp on the insulation and increase energy consumption."

  3. Expert Member
    Dana Dorsett | | #3

    I suspect the insulation blanket money would be better spend on rooftop solar. Standby losses on electric tanks are pretty low, and the HPWH won't last nearly as long as the PV.

    If it isn't already insulated, insulating the hot water distribution plumbing to at least R3 would deliver better energy savings than more insulation on the tank itself, and would be be cost-effective.

  4. Bozothec | | #4

    Thanks for the comments. I wouldnt have gone with hphw if I didnt put in solar first, so that is done. I read the Stiebel advertising stuff but wasnt sure if I could get much return from wrapping.

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