Is it worth switching to Heat Pump?

NowConfusedAgain

Hi All,

I am considering installing a heat pump but am struggling to see how it financially makes sense.

I have a 2004 timber frame house which we built with good insulation, airtightness and HRV installed.

Heating is a wood pellet boiler I have been servicing myself over the years and even bought a backup one on donedeal to scavenge parts off. I am concerned it may fail and not be repairable which is my main reason for switching as well as getting a bit old to keep shoveling pellets to auger :).

Installed Solar PV in January 2023 which are working well and should pay off in about 3-4 years. BER states house is B3 with a HLI of 1.7.

I got a quote for a heatpump retrofit including radiator and hotwater cylinder replacement of 18.5 K after the 6.5 K grant.

I had not allowed for radiator replacement and hot water cylinder replacement so it is higher than I estimated.

Annually currently I spend approximately 1300 on wood pellets.

I am thinking that an oil boiler replacement would cost 3-4k.

Maybe I am missing something but it looks like it would take many years for a switch to pay off, if at all, so I am leaning to switching to oil and see in the next 5-10 years if HPs become cheaper or better grants.

Any advise appreciated.

Thanks,

NowConfusedAgain

Deagol

I'm in slightly different situation but similar house. 2000 built timber frame, Solar PV etc. Estimate for HP was huge - 50k with 28 radiators new radiators needed.

When I take into account the cost of oil per year (~1000e) to heat the house at the moment and the cost of running HPs they make no sense to install.

I can turn on the oil heating whenever I need it - we typically use it on average 3 hours per day, but the HP's really need to be left running all the time as the system will run most efficiently tha t way. But I calculated with 2.5:1 ratio (averaging it between mild and cold weather) the cost of running it will only be 200-300 a year less.

If on average I turn on the oil boiler 3 hours a day over the 100 days of winter - I use ~1000litres of oil. Cost ~1000euro.

If I leave HP running 24hours a day i end up with a house that's warm even when I don't need it to be. Average kWh a day 30 - x0.23=~700e a year. I could probably get that down a bit with night rate etc, but even getting it down to 500 a year…

Saving 300-500 a year on a ~50k investment simply makes no sense to me. Especially when you consider the average lifespan of the HP units is ~15 years.

graememk

And here's me that just yolo'd it and dropped in a heatpump in place of oil in a 1980 bungalow 😂

My COP is skewed lower than it could be as I'm using a 500L tank as a battery, and heating that on the EV rate (sorta a buffer, but not, as when it's cold, the HP runs directly.

https://emoncms.org/app/view?name=EcoAir&readkey=82a75750e2f56ccdc7e96768b9776268

I boost the temperatures in the evening and have a setback most of the day.

I did change 2 radiators (most of them were doubles already). As them rooms weren't getting up to temperature quickly enough.

The heatpump won't be actually running 24/7, more that it's able to run as the house needs.

1000l of oil assuming a newish boiler is about 8000-9000kWh of heat.

But the quotes at 50k is just ridiculous - almost a "go away" quote.

Ubbquittious

I know we are living in a Celtic tiger society again but 25k for a heatpump and a few rads is phuqqing criminal

A new pellet boiler might cost u 5k for drop in replacement. Heat pump might never pay for itself

jones

https://www.boards.ie/discussion/2058402277/is-it-worth-switching-to-heat-pump

I'm in a very similar situation to you OP. Timber frame detached house built in 2006 with decent enough insulation at build however its not airtight and i also have no HRV - which i'm assuming would need airtightness of the house. I installed an 8.17kw solar panel system with 10kw battery in November 2023 which is working great but i know my oil boiler is on the way out.

In 2022 i toyed with the idea of switching to heat pump but was quoted about €30k to retrofit it (not including grant) and given the price of electricity at the time i thought it was a crazy move and so went with the solar system instead and "worry about it later" for the heating system. I could buy a lot of oil for 30K.

Now that i am generating my own solar i'm starting to think about the heat pump system again when my current boiler inevitably gives up the ghost. I spend around €1,100 a year on oil currently. I think part of the price i received was due to the airtightness that would need to be retrofitted - i just have normal old school vents in all the rooms.

I'm torn on what to do when the boiler goes. i.e. install heat pump or get another oil boiler and install a HRV?

randombar

Just some info from my side.

Boiler blew so needed to be replaced, small extension at the back 10sqm so needed heat. Floors were insulated (150mm) but not ufh.

I said I'd go mad and rip up all existing flooring and mill in ufh and heat pump.

Great to get rid of oil, ufh is much more cozy, loads more hot water.

Heat Pump Installation Cost: € 16,003
- 4 new rads
- 12kW Mitsubishi Split heat pump
- 300ltr Dual Coil insulated hot water cylinder
Grant Administration Fee: € 3,900
Total: €19,900

Grant: €14,350

UFH: €9,000
New flooring: €5000

Total Cost: €19,550

P.S. I took up tiles myself, 50% tiles 50% timber flooring. Worst job ever.

JohnySwan

Depending on the layout of your home, you could consider a couple of air conditioners.

I've a 3 story semi d, 150sq meter, B3. Installed one in the kitchen and one in the landing. They heat and cool the house as needed. We're open plan downstairs and leave doors open upstairs during the day and ajar at night.

Cost was less than 5k. Used 200kwh of energy for the last 30 days. Downstairs 22c and 20c upstairs.

conor_mc

@randombar, what was the €3900 Grant Administration Fee for?

Also, which grant did you get? Was it a deep retrofit grant, seems you did very well to cover 75% of your installation cost!

randombar

https://www.boards.ie/discussion/comment/123262620#Comment_123262620

Green Grant Home Energy Upgrade

3900 is what the company charge to manage all the grant work, substantial I know but they all seem to do it.

There was decent savings all right, I also installed a truck load of panels at a separate cost which made sure I went from a lower B to a higher A

NowConfusedAgain

Thanks all for the comments.

I had a plumber out looking at my project and he agreed that the cost of a heat pump is hard to justify even with the grant. He thought a change to oil and upgraded heating controls would come in around 4500.

No final decision made (as need to use up my pellets 😀) but I am leaning to oil at this stage.

Ubbquittious

https://www.boards.ie/discussion/comment/123263529#Comment_123263529

Whoa a full month's wages for a normal person. Definitely time to start squirreling away money big time so you're prepared when the crash comes

conor_mc

https://www.boards.ie/discussion/comment/123264957#Comment_123264957

Aw, hate to see someone moving to fossil fuel. Burning anything isn’t great but at least wood pellets net out to zero CO2 emissions. Have you given air to air heat pump any serious consideration? Far cheaper than air to water to install, GoCar easier to adjust and get right, but still with the potential to reduce annual spend on heating, especially if combined with other tech (solar PV, battery+EV rate, etc.). Added benefit of cooling in summer.

Paul Kiernan

https://www.boards.ie/discussion/comment/123264957#Comment_123264957

The prices being quoted for heat pumps (to get the grant) are ludicrous! This is what heat pumps really cost -

https://spares-direct.com/collections/air-source-heat-pumps?sort_by=price-ascending&country=IE

With very low night rate/EV rate electricity there's really no point (for most people, those with 4 teenage daughters excepted) in using the heat pump for DHW. Just heat it with cheap electricity/solar/battery.

Radiators are also cheap and may not even have to be upgraded. Most houses are way oversized on radiators and if you normally have them on 6 hours a day at 60C they might work just fine for 24 hours a day at 35C or 40C.

NowConfusedAgain

https://www.boards.ie/discussion/comment/123266386#Comment_123266386

I agree and is not the way I want to go as shown by the fact I put in wood pellets, hrv and significant expense for expensive insulation, vapour barrier etc. However, I need to be pragmatic where the difference in cost is several multiples with potentially no added return during the lifetime of the heat pump.

Boardnashea

Thanks for all the info above.

My pellets are just about to run out, for the last time, in the next few days. There is a Baxi 1.5 Multi fuel Pellet boiler on adverts at the moment looking for a home. We have a old Firebird still working but the whole heating system needs a good once over. The Firebird might not be big enough for the original house plus extension. Currently thinking of a Grant oil and like mentioned above, don't want to going back to oil as primary source but HP might be beyond the existing airtightness and insulation.

Maybe look at external wall insulation to get closer to possible heat need to suit HP.