If you have a new account but are having problems posting or verifying your account, please email us on [email protected] for help. Thanks :)
Hello All, This is just a friendly reminder to read the Forum Charter where you wish to post before posting in it. :)
Hi all, The AutoSave Draft feature is now disabled across the site. The decision to disable the feature was made via a poll last year. The delay in putting it in place was due to a bug/update issue. This should serve as a reminder to manually save your drafts if you wish to keep them. Thanks, The Boards Team.
Hello all! This is just a quick reminder to ensure that you are posting a new thread or question in the appropriate forum. The Feedback forum is overwhelmed with questions that are having to be moved elsewhere.

Heat Pumps - post here.



  • Subscribers Posts: 37,738 ✭✭✭✭ sydthebeat

    actually its the opposite

    underfloor heating is better at maintain a constant comfortable temperature

    radiators are better for quick heating up responses.

    heat pumps and rads are not unusual for retrofit applications

  • Registered Users Posts: 772 ✭✭✭ Dolbhad

    Sounds like UFH may be a cheaper option to run in long term?? Our preferred build has rads but a few others we had looked at but couldn’t secure had UFH on ground floor and I was wondering is that a higher spec thing.

    Coming from what we have now, this is going over our heads. But I love the idea of a constant temp maintained throughout the day in winter compared to turning on the boilder and off. And it being plainly cheaper than if we had to run the heating all the time with the gas boilers.

  • Subscribers Posts: 37,738 ✭✭✭✭ sydthebeat

    UFH is absolutely cheaper to run, as it runs at lower temps then rads. Usually around 35 degrees. Low temp rads usually run at about 45 degs. (Standard rads with oil / has etc run at 70 Deg)

    If this is a new build and you want to keep running costs down then certainly look at UFH in my opinion

  • Registered Users Posts: 757 ✭✭✭ DC999

    With rads, they basically heat the air thru convention (hot air at the roof dropping to met cold air on the ground, so the air ‘cycles’ around the room itself). Air heats quickly but loses heat quickly. It lacks density to hold the heat. So room temp goes up and down as rads go on and off.

    But if you heat a huge slab of concrete (which takes a long time of course), it then radiates that heat into the room. The concrete = thermal mass (that’s something very dense that can hold heat for a long time). And the room can stay are a more constant + comfortable temp. And that heat then also move into the walls (if they are solid) so also helps increase the wall temp – which adds more of a thermal mass to the space.

    We're all come across the idea of thermal mass when standing on cold tiles in bare feet. The cold ‘radiates’ out from the floor into your feet. Gives me brain freeze :) Same idea, but the opposite temp. 

  • Registered Users Posts: 772 ✭✭✭ Dolbhad

    Thanks for the explanation!!

  • Advertisement
  • Registered Users Posts: 11,425 ✭✭✭✭ Ush1

    It may or may not be cheaper depending on many factors. You can have UFH with a gas boiler also.

  • Registered Users Posts: 3,551 ✭✭✭ graememk

    It's a big ol it's complicated.

    There's a lot of work/materials that goes into underfloor, I'd say 5-10k, ufh could add to the cost of the heating system..

    The heating being "on" all the time doesn't mean it's actually on. It will only need to be on if the house needs heat. Both radiators and ufh can do that, irrespective with the heating source.

  • Registered Users Posts: 59 ✭✭ golfhead

    Hi all

    1. I set the base temperature in my house using the Joule sensor at 20 degrees and, using the temperature control system on the sensor, as I understand it, the sensor will kick in when the room temperature falls to 19 degrees and will keep the heat pump running until the sensor reaches a temperature of 21 degrees, at which stage the heat pump will be switched off until the temperature in the room falls back to 19 degrees.
    2. The next day, I set the base temperature in my house using the Joule sensor at 26 degrees and, using the temperature control system on the sensor, as I understand it, the sensor will kick in when the room temperature falls to 25 degrees and will keep the heat pump running until the sensor reaches a temperature of 27 degrees, at which stage the heat pump will be switched off until the temperature in the room falls back to 25 degrees.

    My question is, apart from the extra units used in getting the room temperature to the higher temperature initially, would be heat pump use the same number of units maintaining the temperature in both scenarios above?

  • Subscribers Posts: 37,738 ✭✭✭✭ sydthebeat

    you can, but youve to cool the water coming from the boiler before it enters the UFH... not very economical

  • Registered Users Posts: 11,425 ✭✭✭✭ Ush1

    You'd only need blending valves if your flow temp is too high. Gas can be(and should be for condensing) ran at lower temps anyway.

  • Advertisement
  • Registered Users Posts: 3,551 ✭✭✭ graememk

    The higher the difference in outside and inside temperature the higher the heat loss will be, so more heat will be needed to maintain the higher temperature in the house.

  • Registered Users Posts: 4,306 ✭✭✭ creedp

    You might save a few bob on clothes though, ie. you'd be casting them all off at those temps!

  • Registered Users Posts: 7,844 ✭✭✭ the_amazing_raisin

    Others have given better and more technical answers, but FWIW I've got a heat pump with conventional radiators and it works fine

    It's important that the rads and pipework are correctly sized for a heat pump with a lower flow temp. Given the house is a new build then this should be the case

    I probably don't get the same level of efficiency as others with UFH but I believe I'm still a bit cheaper than gas heating

  • Registered Users Posts: 772 ✭✭✭ Dolbhad

    This is exactly what I was thinking about so thanks for response.

    Most people seems to have UFH in their new builds. Probably a higher spec so didn’t know how someone with rads found it.

  • Registered Users Posts: 155 ✭✭ LastFridayNight

    The new neighbors renovated their house and put in an air heat pump system. The outdoor exchange unit is at the foot of their garden bordering ours. The sound when the fan motor is running is very annoying. We can literally hear it inside our house, which is about 10 or 12 meters away. It's a low drone sound- doesn't sound like something's broken or bad bearings, just the noise of a large motor running. However in our neighborhood, which was otherwise super quiet, it's a pretty invasive sound.

    Before I go talk to the neighbor, does anyone have any ideas on options to limit the noise? e.g. Do these heat-pumps have a 'low noise' setting or can they be housed in some sort of acoustic enclosure ?

  • Registered Users Posts: 101 ✭✭ simpsimp

    Our outdoor unit (Daikin Altherma 3) is at the end of our garden, albeit behind a fence, but it makes almost no noise, even when you're up close to it.

    Probably not much good to you, but just for contrast... Hopefully they will be able to help quieten it down.

  • Registered Users Posts: 7,844 ✭✭✭ the_amazing_raisin

    They can sound pretty loud when they're running a defrost cycle, bit like a squeaky wheel

    Most of them have a quiet mode which will run at a lower power

  • Registered Users Posts: 554 ✭✭✭ Mr Q

    I have a Nibe similar to yours but with a smaller outdoor unit. I put a small consumer unit on my HP, pump and controls to know how much energy the heating system is using. There is no way of measuring the kWh used on the Nibe unit as far as I know of.

    Charging 25 euro yearly for a premium version of an app is taking the piss in my view on such an expensive unit.

  • Registered Users Posts: 53 ✭✭ johndoe11

    I think one of these gateways works with Nibe and other brands. I got one for a Bosch, not cheap, but it is very easy to install and integrate with home assistant. It sends all heat pump sensor data and consumption data.

  • Registered Users Posts: 1,412 ✭✭✭ thomas 123

    Hi again folks,

    Anyone got any feedback on Ground Source heatpumps?

    Again for my new build, i'm considering going a2w or groundsource.

    I have half an acre, with a large front garden - would have about 400M2 to spare there that could be used for a horizontal system.

    Thinking if I can dig this myself id bring down the cost of the system closer to the going rate for the a2w so it appears to be a viable option.


  • Advertisement
  • Registered Users Posts: 11,583 ✭✭✭✭ KCross

    Technologically GSHP is better than ASHP all day long. If you can get GSHP for in or around the same price of ASHP you should grab that with both hands and do it.

    You will need to check with an install company if your soil is suitable and if you have enough space. The length of the collector will depend on the heat demand and size of HP you pick so you need to be given some advice on that front and not just assume your site is suitable.

  • Registered Users Posts: 482 ✭✭ babelfish1990

    I did ground source with a vertical borehole, and am very happy with it. I did it mainly for aesthetic reasons - didn't want an A2W unit in front of the house. While it is somewhat more efficient than A2W, you won't recover the additional cost back on the efficiency improvement alone. However, I firmly believe that the extra lifetime that can be achieved by having the heat-pump indoors will eventually pay back....if you live long enough and stay in the same house. I live near the sea, and I suspect that A2W units outdoors are unlikely to last more than 10-15 years in Irish weather. I have just thrown out 2 gas boilers that were 23 years old, and could probably have been kept going with a few spare parts which are still available. I would expect an indoor GSHP to last 20-30 years, even if it needs a new compressor or the odd spare part. There are some other advantages, like the near-silent operation of the GSHP vs the noisy fan on A2W. There is also the asset value of the collector, which may add to the value of your property if you have to sell it. The collector will probably have a lifetime of 100 years, so should remain an asset well into the future (if future generations have'nt figured out a better way of heating houses!).

    It is important to size your ground source collector. Your heat-pump supplier should be able to do this for you. 400sq m might be at the low end of the area required for a horizontal collector, but might work if the house is not too big, and very well insulated.

  • Registered Users Posts: 757 ✭✭✭ DC999

    Well explained and you cover the less obvious benefits like extending the life of it (hopefully)

  • Registered Users Posts: 1,412 ✭✭✭ thomas 123

    Thanks a million!

    There are all sorts of collectors on the go at the moment usually when you go online you see the big one that goes around a perimeter of an area, now there seems to be something that looks like underfloor heating pipes - Ill contact a few companies and see what we can do.

    With a GS heatpump there is no equipment outside right? Aside from the collector pipes that would then run into the plant room?

  • Registered Users Posts: 482 ✭✭ babelfish1990

    Yes with GS, there is no equipment outside. Good luck!

  • Registered Users Posts: 1,637 ✭✭✭ podge3

    Anyone know how to register an Ecodan HP for warranty purposes?

    I've tried emailing the only email address I could find for Mitsubishi Ireland HPs and also tried contacting them through Facebook but no reply to either.

  • Registered Users Posts: 1,395 ✭✭✭ THE ALM

    Is the HLI figure of <2 taken from DEAP in order to qualify for the grant?

    Due to do the assessor course next week and have been using our house as a template to get a feel for it. Original BER has us at a B2 with an HLI of 2.237 and when I enter our details with upgraded windows and doors it seems to have pushed us to A3 and HLI 1.829.

  • Registered Users Posts: 1,230 ✭✭✭ newhouse87

    Looking at this i don't know what's going wrong with my heating. I used 2300kwh for nov/dec. In January i have been using 33kwh a day. 242sqm new house. 80% of my kwh are the heat pump as it has separate meter i can monitor. House now fully insulated. Attic only finished second week in jan and in the sitting room that was freezing at 14deg, now have 19 most days without heat pump so thats good at least .Getting air tightness test done soon to see if i have draughts i dont know about.

  • Registered Users Posts: 7,844 ✭✭✭ the_amazing_raisin

    I think you kinda answered your own question. No insulation in the attic meant the heat was just escaping and the heat pump couldn't keep up, so it was running full bore all the time

  • Advertisement
  • Registered Users Posts: 1,230 ✭✭✭ newhouse87

    I seriously hope that was it but most of the attic was done for the cold months just not over sitting room and along eaves on 1 side.