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Electric underfloor heating (does it work at all)?

  • 17-09-2023 9:52am
    Registered Users Posts: 2,287 ✭✭✭

    Doing a bit of a renovation downstairs, two rooms, 10sqm and 15sqm in size (ufh area will be 7sqm and 9sqm, 1kw and 1.5kw) and thinking of doing ufh under the laminate, either the foil type (not infrared) or the one you pour the levelling compound over. These guys do both types.

    Not sure if it's worth it at all, as in will it work at all to heat the rooms or will it just be a waste of money and barely heat the laminate in real life?

    Anyone here that installed something similar that can give me real life experience of the system?


  • Registered Users Posts: 1,427 ✭✭✭Big Lar

    Don't have it but I would imagine that it would be expensive to run, like for every 1Kw of electricity you put in would you even get 1Kw out in heat? Whereas with a heat pump, oil or gas you get more out than you put in.

  • Registered Users Posts: 2,287 ✭✭✭SD_DRACULA

    That's the thing, main heating is gas anyway, this would be for those times in spring/autumn when there is some excess PV but at the same time once I move to the pinergy tariff I will want to get paid for every singe unit instead of using it.

    Bit of a conundrum.

  • Registered Users Posts: 5,872 ✭✭✭Chris_5339762

    In my mind it works only ok - but what it does let you do is walk around on the floor in bare feet in the winter, as it'll be marginally warmer.

  • Registered Users Posts: 11,164 ✭✭✭✭the_amazing_raisin

    I'm not convinced you'll get much use out of it, it'll need 2.5kW of solar to run which means it's a reasonably sunny day to start with

    Unless you're going to hook it up an Eddi or something that can vary the input power

    For the expense, some more batteries seems like the better return on investment

    "The internet never fails to misremember" - Sebastian Ruiz, aka Frost

  • Moderators, Home & Garden Moderators Posts: 6,001 Mod ✭✭✭✭graememk

    Well oil or gas is 1kwh in, less than 1kwh out.. but the price per kWh is a lot cheaper

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  • Registered Users Posts: 1,443 ✭✭✭DC999

    My folks tried the electrical type under the floor and didn't work really. Was a Diy install. Maybe my dad didn't put a foil back on it so some heat was unexpectedly lost going under the house.

    It's an extension so has several external walls and no insulation. Really the room needs insulation. It was on 24x7 at one point and made the room not cold (from a freezer prior to that) but it wasn't warm. It chews energy when on 24x7. Has a tile floor.

    You could feel the parts of the floor that had it as they were warm (not hot). That said, maybe in a well insulated room it would be fine.

  • Registered Users Posts: 2,287 ✭✭✭SD_DRACULA

    Even in a bunch of videos on YT it says it's to keep the tiles "warm" and not much about using it as primary heat source.

    Seems that to do it proper you also need 10mm cement board under the UFH (on top of the concrete floor) for extra insulation and it raises the floor by almost 15mm (including the ufh foil) which is quite a big jump once the 12mm laminate goes on top. I think there's 8mm there right now with some very thin underlay and the floors are flush between the rooms.

  • Registered Users Posts: 60 ✭✭steamdave

    I'm doing a house renovation and have decided to remove the old water radiator and put UFH in the bathroom. I was advised to ensure there will be insulation under the heating mats. It will only be used to take the chill off the floor. It will be complimented by an infra red radiator. Total running per day will only be about 1 - 1.5 hrs.

    Main advantage for me will be to warm the bathroom when the oil fired central heating is not running. Hopefully the pv solar will be able to take the load.


  • Registered Users Posts: 2,287 ✭✭✭SD_DRACULA

    I went for it, more curiosity than practicality, will post back here if it works I guess

  • Registered Users Posts: 1,443 ✭✭✭DC999

    Brill, I'd like to get it myself. So do please share. I guess once the floor is insulated below it, then heat should rise into the room. In my folks case I reckon most heat was lost below the house in the ground floor toilet extension.

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  • Registered Users Posts: 2,287 ✭✭✭SD_DRACULA

    100%, will need a min of 6mm under it, 10mm is better if you got the height.