Heat Pump Air Conditioner/Water Heater

Discussion in 'Off Grid Living' started by BenP, May 9, 2018.


  1. BenP

    BenP Monkey++

    This is my off-grid Rheem heat pump water heater/air conditioner setup, it draws 300-400 watts. I had to replace the elements with 2000w 480v elements which only draw about 500w at 240v because even when it is in "Heat Pump Mode" it will still fire one of the elements if the water temperature gets below 70F.

    Water Heater.
     
    techsar, Dunerunner and Bandit99 like this.
  2. azrancher

    azrancher Monkey +++

    Did you pour that concrete wall yourself, wondering out loud where you get the thingies that hold the plywood at the proper width, you know the thingies that leave those cone shape holes?

    Rancher
     
    sec_monkey likes this.
  3. BenP

    BenP Monkey++

    They are called wall ties, you can find them on ebay. It is more difficult to find the hardware that locks the wall ties and forms together, I have not seen anywhere you can buy it new. We have local concrete form rental place and they sell the wall ties and rent everything else.
     
  4. oil pan 4

    oil pan 4 Monkey+++

    I was just going to leave the heating elements off on mine, which has 3 settings, heat pump off eater heater operates 2 heater elements like normal, heat pump only and heat pump on in place of the bottom element and the top element will still come on if needed.
     
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  5. ghrit

    ghrit Bad company Administrator Founding Member

    For SURE I would move that conduit behind the flue to someplace away. Plastic, if I read it right, does not too much care for heat, insulated flue or not.
     
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  6. techsar

    techsar Monkey+++

    That's a cold air duct...

    Looking at customer reviews shows a disturbing trend...best case, 50% have issues that leave the unit inoperable.

    Good idea, but not ready for prime time...
     
  7. azrancher

    azrancher Monkey +++

    I guess I don't understand how that all works if that is a cold air duct, so heat pump dumps exchange heat to heat the water (in the cooling cycle), so you get hot (warm) water, how does it give you air heat, especially when when you are in the cooling cycle and you don't want/need the air heat? I'm confused.

    Rancher
     
  8. ghrit

    ghrit Bad company Administrator Founding Member

    Oh. Well then, it becomes a different issue altogether.

    Me, too. Massively.
     
  9. techsar

    techsar Monkey+++

    From Rheem's info, there is no provision for heated air. Keep in mind this is primarily a water heater, the byproduct being cool air. :)

    @BenP , please correct me if I'm reading this wrong!
     
    BenP likes this.
  10. BenP

    BenP Monkey++

    This is only used for cooling, it pulls heat out of the air and puts it in the water then blows cold air as a byproduct. We don't use it for heating, we have a wood stove for that.
     
    techsar likes this.
  11. BenP

    BenP Monkey++

    I tried to disconnect the heating elements but it would throw an error message during it's startup test and would not run.
     
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  12. BenP

    BenP Monkey++

    I had the GE Geosprings version of this in my old house and it had a terrible reputation but I never had any trouble out of it and the people that live there now still use it.
     
  13. 3M-TA3

    3M-TA3 Cold Wet Monkey

    Maybe it's just a continuity check. Perhaps a resistor with less power draw could fill in and save the power?
     
    BenP likes this.
  14. Dunerunner

    Dunerunner Brewery Monkey Moderator

    I would move it away from the wall some an put an insulation blanket on it. I have a neighbor who bought won of these when his original electric water heater failed.
     
    BenP likes this.
  15. BenP

    BenP Monkey++

    I probably will when I get time, I also need to insulate the hot pipes, we moved in before I was finished with the house so I am behind the curve on several fronts right now.
     
  16. ghrit

    ghrit Bad company Administrator Founding Member

    While you are at it, put it up on masonry so condensation and/or flooding won't rust it out prematurely. Concrete would be nice, but pavers will work. (Don't ask.)
     
    Dunerunner likes this.
  17. oil pan 4

    oil pan 4 Monkey+++

    I got an old stand alone unit.
    No gold plated junk.
     
  18. Tempstar

    Tempstar Monkey+++

    Not widely known is a device called a Desuperheater. They can be added to a heat pump or A/C unit to make hot water when the cooling is on. They are real popular on geothermal heat pumps as they can also make hot water in the heating mode. They also increase the efficiency of A/C units in the summer. They are also found on grocery stores where they use the waste heat from refrigeration to heat the water and even the store. They are a coaxial copper coil with hot compressor gas in the outer shell flowing over an inner copper tube with the water inside, and a small pump. And yes, I have one on my heat pump and it makes all of my hot water in the summer.
     
  19. Cruisin Sloth

    Cruisin Sloth Special & Slow

    Called FORM TIES
     
  20. Cruisin Sloth

    Cruisin Sloth Special & Slow

    Both of these are huge amounts of power for an off grid system
    S
     
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