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Managing Geothermal UFH efficiently

  • 23-12-2021 2:50am
    Registered Users Posts: 1,729 ✭✭✭


    Staying at a place now with geothermal. Every room is zoned, with basic stat with no program. As a result the pump is on and off constantly with about 14 different zones in total making their own unique demands. This on off doesn’t seem efficient to me with heat pump having to work a lot, and pumps at two manifolds having to work. Maybe my perception is wrong and this is all actually fine? Waiting for the first bill!!

    Assuming my hunch that the current operation isn’t efficient, would it make sense to just leave most of the zones open and use maybe 3-4 stats online as “masters” which actually call for heat?

    Do the basic analogue stats need to be binned and replaced with something that allows me to align heat pump usage a bit more, for example focusing usage on the esb night rate? If this is a suggestion, do they all need to be changed?

    What are people doing with their hot water, using heat pump?



  • Registered Users Posts: 1,729 ✭✭✭poker--addict

  • Registered Users Posts: 619 ✭✭✭tedimc

    When we fitted ours, the company said that they have moved away from individual stats altogether. The call for heat is made by the heat pump itself based on the amount of heat loss from the water in the UFH.

    Theory is, when the slab heats to 20 degrees, the heat loss will reduce in the water flowing through the pipes.

    Try leaving it on a low heat setting continuously for a week or so to see if it makes a difference. Ours is on all year round, but I do need to turn it up a degree or two around mid winter. It also heats our hot water.

    Total ESB bill for year is ~€1800. No other heat source like stove, etc.

    My understanding is that generally, the longer the heat pump runs the better. So continually kicking in and out is not good for the compressor.

    You could also try timing the heatpump. On for maybe 3 hours in the morning, and another 3 in the evening - but this will depend how well insulated the house is. We do this in my mum's house, but she has a oil condenser boiler with UFH.

  • Registered Users Posts: 1,729 ✭✭✭poker--addict

    900e bill has arrived.


  • Registered Users Posts: 870 ✭✭✭keno-daytrader

    14 zones for a heat pump is nuts.

    Use 2 zones, 1upstairs 1 down.

    ☀️ 6.72kWp ⚡2.52kWp south, ⚡4.20kWp west