Heat Pumps - post here.

Do not buy a Dimplex, I have one and while it works fine, that's all the positive things I have to say about it

Get a reputable brand with lots of experience, Daikin, Mitsubishi and Panasonic are 3 I can think of off the top of my head. They all have models that allow cooling as well

Consider the support options after installation. For example there's one company that handles all the support for my area so I'm stuck with them for organising a service

Ideally try to give yourself some options

Hello everyone. Really interesting thread. We are in a 4 bed 1980’s detached bungalow. It’s a c3 heated by gas boiler. We have a stove also. Our plan was as it was meant to be a forever home, to upgrade in future

Due to change in living circumstances (moving closer to family) we are looking at purchasing a4 bed semi detached house. It’s a ecodan air source heat pump. But it will be rads on both floors - not under flooring heating.

My understanding is underfloor would be better as may heat up quicker than rads. But dads should be able to maintain the same heat.

Just wondering if anybody has rads instead of under floor heating and if so, how do you find it?

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.

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. 

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

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.

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

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.

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.

Thoughts?

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.

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?

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.

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.

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.

Well insulation wasn't it, used 33kwh overnight on heat pump. something seriously amiss with rooms, sitting room stat calling this morning for heat, no evidence of heat under while main bathroom v hot. Im going to have get commissioning fella out to see as plumber hasnt a clue.

Yeah think they are messed up but not sure. Im still thinking my heat pump isnt efficient enough even it rooms its heating. Like how long should a room take to heat back up to 21 once it falls to 20. Can it take hours? Ill post pic my manifold shortly when i get it. How much kwh should a heat pump use in an hour? 33kwh from 10pm to 7am seems mental.

Thats the manifold. Often notice that when kitchen calls for heat all actuators on left open aswell as 2 on main block but when other rooms call for heat the actuators on left dont open. 33 is just for heat pump. Whats best way to figure out if sitting room is actually being heated. Main bathroom very hot this morning from sitting room stat calling for heat. All help much appreciated.

Thanks man, will aim to do that on my day off. Finding it hard to determine if sitting room is getting any heat. Timber floor never feels warm and stat temp doesnt go up after couple hours i think. Stuipd question but are the actuators on the left exact same purpose as main block. They only ever open when kitchen calls for stat.

Yeah mine have red bit visible when they are opened too so no need to open wiring centre so?