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Anti-freeze mixture for geothermal heat exchanger

  • 02-03-2010 7:23pm
    Registered Users Posts: 591 ✭✭✭

    I need to top-up the resevoir on a heat-exchange pump for the fluid that gets pumped around under the garden.

    I have the recommended mono-ethylene glycol (undiluted).
    Is there a recommended dilution for this? If so is it 50:50 and is purified water suitable?



  • Closed Accounts Posts: 672 ✭✭✭items

    The dilution depends on type of heat pump you have, you should have some heat pump manuals giving information on brine dilution.

    When you say top up, is the level bottle low, if so how much?

    If you've not lost too much its possible to just add some plain water, their is a lot of water in ground collector, 600 mtr + of pipe work. A few ltrs of fresh water shouldn't upset the existing dilution to much to cause major problems, but as always refer to maintenance manual.

    If you've lost a lot of water, which is sign of possible leak its not a case of just mixing a few more ltrs and pouring into ground collector. The filling process is a bit more complicated. Before heat pump can return back to normal use the brine pipework has to be recycled / circulated for a number of hours and have its dilution monitored all using specialist equipment.

    A wrong dilution can lead to poorly performing ground collector even risk of complete freeze over locking out heatpump so be careful.