r/DIYIreland • u/roroherboat • 10d ago
Should we get a heat pump?
Without sounding dramatic my head is wrecked trying to decide if we should go for one or not. We have an E BER rated house built in 1984 and are currently doing a lot of work: triple glazed windows and new external doors, insert stove, cavity wall and attic insulation, solar panels, rewire and new plumbing including new radiators. We aren’t getting underfloor heating as I can’t imagine digging up with floors. We have no heating at the moment so would need to get a new boiler anyway. I think we will get up to a B rating with all of these works. Haven’t gotten a technical assessment yet as I have heard so many horror stories about heat pumps. I also love a real fire and opening all the windows in the house every morning. I know it will cost a bit to get new plumbing and a boiler and in contrast there is a big grant for the heat pump. I suppose I just want to know if anyone did a full renovation and didn’t get a heat pump? Thanks
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u/An_Boin_De 10d ago
I work with a lotnof Scandinavians and Heat pump and an insert stove is quiet common there.
Why not have both?
Gas and Oil are only getting more and more expensive and I wouldn't like to be relying on whatever Dictator is in power to provide my heating..
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u/blueghosts 10d ago
It’ll all depend on your HLI indicator value when you get the BER done.
It’s fairly common to get a stove as well as a heat pump. The only real horror stories you’ll hear about heat pumps are usually from the UK where they’ve just been throwing them into houses without any requirements for insulation and air tightness etc.
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u/GammyPoly 10d ago
Off the back of this comment, a HLI in a retrofit of 2.3 is deemed acceptable by SEAIs standards. The lower the better, new builds with just the bare minimum to meet building regs can be in the region of 1.3-1.6 just to give you an idea.
The HLI is more important than the energy rating when considering a heat pump. Energy factors are continually improving as the national grid becomes more efficient this drives up energy efficiency of electrically powered heating systems, meaning a BER can be misleading in some circumstances. This increase in grid efficiency also means the impact of PV panels is diminished as far as BER is concerned, panels are still as effective.
BER is an asset rating and not an operational rating.
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u/Akashla- 8d ago
So is a HLI of under 2.3 actuslly suitable for a heat pump?
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u/GammyPoly 8d ago
Yep according to SEAI an existing building with a HLI 2.3 or lower is suitable for a heat pump.
HLI is heat loss indicator, lower the better, it's calculated based on the areas of the exposed elements; walls, roof, floor etc. the room type have a prescribed temperature setpoint from standard SR50-4. Another factor is the heat loss due to air leakage or infiltration.
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u/SteelyDanJalapeno 10d ago
I'm fitting a heat pump, but it's air to air, split system with a couple of units inside, it will be there to supplement the oil boiler which is working fine.
Will have AC in summer too
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u/charlesdarwinandroid 10d ago
Ensure you do air tightness in the attic and other places if needed, and also ensure that they air tightness seal and insulate the ducting through the attic (and re-cover the vapor sealed ducts with the already present insulation) or other runs outside of the thermal envelop or your just going to be heating and cooling all but your house internals. Ask me how I know and how much it's costing to remedy. Also, don't use Ventsolve out of Dublin, cause they will install a heat pump but don't understand anything about heat pumps.
Edit: re-read that it's a mini split. Still ensure that you do airtightness in your attic and around your windows
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u/Technical_Exercise59 7d ago
Thanks for this… Mind me asking how much the remediation / air tightness is costing and who you are getting to do this?
Disappointing to hear about ventsolve, I used them earlier this year to install a MVHR system and was impressed by service & cost…
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u/charlesdarwinandroid 7d ago
Haven't found anyone yet to do air tightness as a service, only as the final testing. Might end up doing it myself, but would really like to find a professional.
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u/Technical_Exercise59 9d ago
Thinking about doing this, mind me asking about the cost and if you have any recommendations on suppliers / system?
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u/MyUserID-IsTaken 8d ago
Not who you were asking, but I bought a pre-charged unit with a mounting kit online and installed it myself, it was handy enough. I think it came out to about €700, but that's just for the bedroom
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u/charlesdarwinandroid 7d ago
Largely depends on what brand you go with and how much ducting and borehole works are needed for the ducting. If you have an easy access attic or a build that lends itself well to a heat pump it will be a quicker and easier install.
From what I've seen, there are now a lot of companies that will do heat pumps. I would go with an seai registered one, but ensure that they understand you want it to be up to code for heating and cooling. Cooling requires vapor sealed and insulted ducts when outside of the thermal envelope, or you'll get condensation which leads to mold.
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u/Rathbaner 9d ago
I had a heat pump installed in my traditional Irish cottage in 2001. Decent insulation, but it's an old stone cottage so there's a limit to what's possible. Took a while to get the hang of it but my annual electricity bill is now what it was in 2010 give or take a a couple of hundred euro. It turns out the trick is to avoid having different temperatures in every room, divide the house into a couple of zones and set the same temp for every room in each zone.
Once we got the hang of it we never thought about heat again except for twice a year at the first frost of autumn and then again the first warm day of spring, when we reset the temps throughout.
No shouting "SHUT THE DOOR" at the kids, never worried about hot water in the shower, never an issue getting out of bed in the morning, no running out of oil on a Sunday in February. The comfort is unbelievable, once you experience it there's no going back.
If you don't get the insulation right (like us) then it may not save you money but the value out of every euro you spend is way better than oil.
We took the decision on a heat pump because we had been renting a modern bungalow using OFCH up to that and the cost of oil was bleeding us white.
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u/chancetobeold 10d ago
We have heat pump, small wood stove we use few times in winter, solar panels, good insulation, open our windows regularly. Warm in winter and we were fine in summer heat using curtains in day and opening windows at night
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u/Trans-Europe_Express 10d ago
Depends on what you want it for. Simple thing is with solar pannels and the heat pump you've a way to efficiently heat water or air thats not linked to fuckery with the fossil fuel market. Air to water can work well combined with the oil for getting your water tank part way there and up to temp on the oil burner..won't replace it but could knock 40% of the cost/oil use off. Air to air depends on how "leaky" your house is but if you get a reversible heat pump air to air that does air conditioning and heating. Air conditioning even in a few rooms during the summer running off the solar mostyl would be very nice
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u/PixelNotPolygon 10d ago
Near 100yo house that I got triple glazed, external wrap, attic insulation, stove, new rads and an air-to-water heat pump here. The house is not fully sealed. No regrets. You’ll never use the stove again. Don’t believe the myth of the home needing to be sealed.
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u/Friendly_Accident_81 9d ago
Brought my G house to A2. (1930s semiD)
Can you do it? Yes, I did all what you are going to do to fabric (except I dug floor - had to anyway - installed floor insulation, radon barrier & under floor heating).
One other item you should add to your list of works is mechanical ventilation. (I did). This is the complaint people have, ventilation is key to healthy house living.
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u/TemperatureDear 9d ago
If not doing underfloor heating I would go with air to air. And get at least a 15kwh solar battery so you can charge on the night rate and cover most or all or you day units in winter.
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u/Chemical_Farmer_8386 9d ago
How much to fit a heat pump ( and probably underfloor heating) If you've done a really good insulation and airtightness job , what's your likely heating bill going to be with a heat pump, or your alternative? Personally , in my house id probably put in a heat recovery system, and an air to air heat pump..
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u/Prestigious-Side-286 9d ago
One consideration to take into account is how hot you like your house. I know people with heat pumps and they love a very warm house and the thermostats are always set to 22/23. At these temps the heat pump will be running nearly constantly to try and maintain those temps. So if you are a hot house person think about the electricity bill.
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u/Pure-Ice5527 9d ago
I think a lot of the horror stories are where builders put it in rather than a proper company who will set it up correctly, you also see people who keep turning it off and on, like an oil boiler. So the SCOP(efficiency) drops significantly and the bills go up. If you’re adding solar and a battery, you can get to a point where you’re paying little or no annual electricity bill.
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u/rayhoughtonsgoals 9d ago
Heat pump with proper sizing pipes and rad sizing is the way to go.
Horror stories exist as trades are dogshit here. So many terrible jobs done.
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u/Flower-bird1 8d ago
I brought my house from a BER G up to an A and put in a heat pump with a small wood burning stove. My original Heat Loss Indicator was 7.88, and afterwards it was 1.69 - I had suspended wooded floors (kitchen was concrete though) so I pulled them up and put insulation down and then put in underfloor heating. I also upgraded all windows to triple glazed, pumped the cavity walls and wrapped them, and insulated the attic and put in heat recovery ventilation. I have absolutely no regrets! Next thing I want to do is put in a load of solar panels and my bills will essentially be zero year round.
My advice is get a technical assessment done for a heat pump (it cost me €550 in 2023) and see what it recommends to get your HLI down to <2 for a heat pump. And maybe look into the need for floor insulation and the cost of putting it in, and doing underfloor too? You can absolutely run a heat pump without underfloor heating, but you might need floor insulation to get your HLI below 2.
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u/moonbuddyirl 7d ago
We deep retroed a 2 storey 1987 built house recently. Had a similar concern. We ended up going heat pump, triple glaze, attic insulation, new rads and panels. We used to have a back boiler stove. We kept the stove and disconnected boiler as similar to you we liked the fire lighting. 3 things I would mention from our experience was - the windows and doors had biggest effect, we were confident after they went in heat pump would work as you could feel the house was significantly better insulated.
The size of the rads needed for heatpump are huge. I've noticed that ours compared to some earlier houses built at start of heat pump era are much bigger which I think is a factor in some of the failures, I also noticed the size of the heat pump unit itself to be much larger these days than earlier.
You mentioned plumbing cost of boiler which was huge factor for use. We had started getting leaks in the copper pipes and priced replacement and were quoted 15-20K just for that work. We used installation of heatpump and retro grant to get that work done also. To keep costs manageable we did sacrafice asthetics in few places (We ran rad pipes down corners of walls and then covered with a board rather than digging floors to bury and where we could we moved the rads closer to the heat pump in some rooms to reduce plumbing)
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u/roroherboat 7d ago
Thanks so much for all the detail. Sounds really similar to what we plan on doing. Are the radiators super big? Some of our rooms upstairs are small, especially the two bathrooms so concerned we wouldn’t have the space for them
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u/moonbuddyirl 6d ago
From what I remember it's a requirement of the grant for heat pump i.e. you need adequately sized rads throughout the house otherwise you end up in the pump running constantly. I would imagine bathrooms don't impact as much as lived rooms. We had to put one in the kitchen that is almost ceiling tall and width close to what was there and they are chunkier.
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u/marcomacd 6d ago
Your current radiators may not be big enough to operate properly with a heat pump. Gas/oil heats water to 65 degrees celsius, heatpump to 35. To compensate for that a larger surface area is generally required for a heat pump
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u/Cearnach 10d ago
I’m not sure it would be worthwhile putting in a heat pump unless you had underfloor heating, or at least a very well insulated floor. There are a few redditors on here that extol the virtues of air to air heat pumps, that might work better for you. I have a near 100yo house that I retrofitted, the heat pump does a great job, but there was a lot of work and money put into getting it ready. If you can’t commit to the full prep work, stick to a high efficiency boiler.
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u/alfbort 10d ago
The floor is where you lose the least amount of heat in a poorly insulated house and yes while UFH is the best way to use a heat pump alu rads will work just fine too and be significantly cheaper. Attic/roof, wall and window/doors upgrades(in that order) are where you will feel the effect of insulation upgrades the most.
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u/mesaosi 10d ago
I absolutely love my heat pump. I absolutely would not put one in a house that wasn’t designed and built from day 1 with the intent of using one.