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  1. #1
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    Swimming pool heat pump



    Hi all, needing some advice. We have been asked to look at a swimming pool heat pump which is under warranty. it has worked well for the past 5 months but has recently started icing up on the evaporator. The heat pump is located within the pool building (around 18c today) and expels its air through a short duct to the outside.
    Refrigerant is R410a, suction pressure around 6 bar, high side around 18 bar. Suspected system was short of gas, recovered and weighed it, not short, recharged it. When running the system the whole evap begins to frost, which is no surprise I suppose as its evaporating below zero but we were unable to get the pressure up.
    We spoke to an engineer who does work for the supplier who said they had had some bother with incorrectly set expansion valves, after adjusting the valve there was still little difference to evap pressure. Exposed the valve bulb and heated it and the valve clearly modulates.

    Any ideas guys?

    Thanks



  2. #2
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    Re: Swimming pool heat pump

    check coils are clean - get nitro on em- checkur superheat, any dampers that are operating correctly and not slippin on shaft, also filters clean on air inlets- txv bulb insulated

  3. #3
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    Re: Swimming pool heat pump

    Cheers install, evap coil is as clear as a bell, no dampers involved and no filters. Bulb is insulated, opened valve to try and increase evap pressure but it made no difference, however valve does modulate. Do you think it could be to do with the valve?

  4. #4
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    Re: Swimming pool heat pump

    check ur superheat/subcooling

  5. #5
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    Re: Swimming pool heat pump

    I should have said, heat pump is heating the pool water, it is a self contained unit located within the building so air passing through the evap is at around 18c, this air is then expelled out of the building.

  6. #6
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    Re: Swimming pool heat pump

    lower the pool water setpoint so it reverts to heating the air- see if the pressures change- usually leaks onthe o ring on a danfoss solonoid

  7. #7
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    Re: Swimming pool heat pump

    Evap fan running? Properly?

    Airflow into/out of evap restricted? Leaves, grass, paper?
    Last edited by desA; 07-11-2013 at 09:24 AM.
    Engineering Specialist - Cuprobraze, Nocolok, CD Technology
    Rarefied Technologies ( SE Asia )

  8. #8
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    england
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    Re: Swimming pool heat pump

    has the unit got a defrost cycle

  9. #9
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    Re: Swimming pool heat pump

    the evap unit in the room is the room pressurised or is the air blowing back into the room ( is there airflow through the evap)?

  10. #10
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    Re: Swimming pool heat pump

    I wonder if the duct to the outside of the building could be enough to restrict air flow through the evap. Not been back yet, but think I will remove this before going any further.

  11. #11
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    Re: Swimming pool heat pump

    check the outlet grilles as they can get ****ted up due to bird mesh/insect screens

  12. #12
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    Re: Swimming pool heat pump

    They were clear install, I can't think of any other way to get the pressure up other than restricting the water flow. The heat pump is only there to maintain water temp. There's an oil boiler there to bring it up to temp.

  13. #13
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    Re: Swimming pool heat pump

    Water temp in/out
    air temp in/out
    subcool
    superheat
    what water temp is it maintaining at the moment, has the water flow rate changed, ie pool not heating quick enough so pump speed upped? Is there a cover for the pool? is is a Calorex unit?

    al
    Mostly found in the southern part of this green and pleasant land.

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