Heat pump water heater or???

Discussion in 'Water Heaters and Softeners' started by not-a-plumber, Jan 5, 2019.

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  1. Jan 5, 2019 #1

    not-a-plumber

    not-a-plumber

    not-a-plumber

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    I would like to find a practical way to save energy on my domestic water heating.

    I have an all electric home with an 18 year old Marathon 50 gal water heater (low boy) in a sealed crawlspace. This heater has a lifetime warranty on the tank and has never given me any trouble. I flush it annually.

    The crawlspace is sealed, clean and partially conditioned with dehumidification as needed. The headroom is about 56” and the area is approximately 8500 cubic feet.

    My well water is pretty soft and runs through a whole house sediment filter and a water softener (mostly to remove a small amount of iron and any taste of minerals).

    Since the headroom is limited, a conventional heat pump water heater won’t fit, and I’d like to keep the water heater in the crawlspace if possible.

    I looked into add-on heat pump exchangers like the Airtap A7, the Nyletherm and its replacement the Geyser R and RO. They are discontinued and this technology appears to be obsolete. Maybe they were not as efficient as they should have been or maybe their limited heat exchange area was problematic, I don’t know.

    There are a few split system heat pump water heaters with the Sanden SanCO2 system from Japan getting good reviews. However, at $4,000.00 the payback doesn’t make sense to me.

    I would also like the flexibility of utilizing the conditioned discharge to cool and dehumidify the crawlspace in the summer, but I would like to pull and/or reject the cold air from/to the outside in the winter.

    Since heat pump recovery is slow, whatever system I end up with, I’d like to keep the Marathon tank to increase capacity. I assume that I would use the efficient water heater first and then feed the Marathon in series to hold and maintain the heated water, but…

    I try to heat my house with a wood stove in the living room and use the upstairs and downstairs heat pumps only when the stove can’t keep up and for A/C in the summer, so a de-superheater on one or both units would only help me when air conditioning.

    I’m open to any ideas on equipment and on how to tie in the Marathon tank as part of the new system.

    Thanks
     
    Last edited: Jan 6, 2019
  2. Jan 12, 2019 at 4:43 PM #2

    not-a-plumber

    not-a-plumber

    not-a-plumber

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    Let's simplify this. Does anyone have experience with the Sanden SanCO2 system ?

    Is there a comparable system by another manufacturer that is more affordable?
     

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