Boiler to Heat Pump Switchers, Are you still happy?

Burti16

Sleeper12

The answer to the questions will be based on the insulation /air tightness of the house and if the heat pump is correctly sized.

There is absolutely no doubt that a property installed heat pump in a correctly insulated home will be far cheaper to run compared to gas and oil. Another factor is that some people use heat pumps incorrectly.

kippy

https://www.boards.ie/discussion/comment/120075964#Comment_120075964

If the house were properly insulated and the oil burner and rads properly specced to heat the house would there be that much of a difference, particularly with electric at its current rate.

The problem with certain things in this country is that they aren't done right and there's very little repercussions. I'd expect heat pump retrofits are the same.

Sleeper12

https://www.boards.ie/discussion/comment/120075996#Comment_120075996

With everything done correctly a heat pump will always be cheaper to run. Even with the electricity prices at the moment.

Burti16

https://www.boards.ie/discussion/comment/120075964#Comment_120075964

Can we not assume that heat pumps are only installed if air tightness standards are met in a certain house? I mean, are contractors installing these appliances if a house has F rating?

Sleeper12

https://www.boards.ie/discussion/comment/120076072#Comment_120076072

No

Installers are installing them in homes not suitable for heat pumps.

If we are assuming that all heat pumps are correctly installed in suitable homes then there is only going to on answer to your questions. Everyone will be very happy with the heat pump and will be saving money compared to gas and oil.

Heat pumps are cheaper to run compared to gas and oil. This is a fact that cannot be argued. Where they aren't it isn't the heat pump at fault. It's the installation or the insulation.

It's also worth remembering that the BER system is a flawed system. The BER assumes that a home has particular insulation purely based on the date it was built. If I put on an extention last year then BER reflects 2022 standards insulation. If I put 100 mm insulation on inside walls in a 1960 house the BER won't reflect this insulation. Just because a BER cert says B2 doesn't prove that the house has adequate insulation

John.G

I really can't figure out why effectively reducing your energy consumption gives a bigger advantage to a HP, ironically, the lower the energy requirements, the less the savings.

Edit: Have now included Gas at a estimated cost/kwh.

Heat Pump COP simple calc Rev2.xlsx

Alkers

https://www.boards.ie/discussion/comment/120076151#Comment_120076151

While I agree with you to a certain extent, the practice of continuously heating all rooms to a reasonably high temperature with a heat pump diminishes the real world savings Vs a modern gas boiler, where many people have room and time based heating profiles.

This was particularly evident during the recent cold snap where many people with heat pumps continued to heat their whole house to 20C almost 24/7 and used a whole load of expensive electricity in doing so.

While gas/ oil may work out more expensive per heat output received, being able to only heat individual rooms as and when you need them can negate this advantage.

We have significantly retrofitted our 1950s townhouse, which is heated by a four year old gas combi boiler. We would never recoup the outlay of upgrading to a heat pump - in 2022, we spent circa 700e on gas and I work from home three days per week. Even if the heat pump was free to run it would still take ten years to pay for itself.

Lenar3556

https://www.boards.ie/discussion/comment/120076151#Comment_120076151

A correctly installed heat pump could well be more expensive to run than oil/gas in a given environment.

The gross energy cost per kWh of electricity is currently in the region of 4.5 times that of oil. Even with an excellent COP, it’s borderline that you will be in a position to offset that price differential.

When you consider the higher initial outlay, higher service costs, and very significantly (as has been pointed out by another poster) the potential waste of having much reduced time control options……..it’s doesn’t make a exceptionally compelling case at present.

FintanMcluskey

https://www.boards.ie/discussion/comment/120077042#Comment_120077042

This was particularly evident during the recent cold snap where many people with heat pumps continued to heat their whole house to 20C almost 24/7 and used a whole load of expensive electricity in doing so.

I dont understand this?

There is 7 or 8 zones in my house that can all be set to just frost protection, so minimal heating can be used

unkel

https://www.boards.ie/discussion/comment/120075964#Comment_120075964

You can't say that, it depends on the price of oil / gas vs electricity

Most people pay around 15c for oil / gas

Some people pay 50c or more for electricity. For these people a heat pump would cost more to run. Of course on top of the enormous depreciation of a heat pump system compared to a fossil fuel burning system. I'm all for renewables, doing more than most people about it in my own home and helping out others, but you have to have a clear and honest financial picture too.

Sleeper12

https://www.boards.ie/discussion/comment/120077160#Comment_120077160

The environment you mention is the insulation & air tightness of your home. I have already mentioned this.

People were conned into replacing perfectly good Bermuda back boilers for condensing boilers. Condensing boilers can be 90% efficient but only in condensing mode. People that turn the heating on full blast to heat up the room or home & then turn it off never get the condensing mode. They never get the efficiency they were promised. The average lifespan of a condensing boiler is only 10 years. Bermuda back boilers that lost a lot of heat up the chimney didn't break & when they did they could be repaired very cheaply. They had no PCB boards. These boilers ran for decades. Some installed in the 1970s are still running today. Many people in my estate have been running the same boiler for 50 years! Any savings made on modern boilers are lost on the maintenance' repair & then replacement over the decades. In the vast majority of cases it was cheaper to keep the old back boiler & lose the heat up the chimney compared to the ultra efficient boiler that costs a few thousand to replace every decade

The pole is pointless in that the heat pump is more efficient that gas & oil. This is a given. The variable between people's experience isn't the heat pump, it is their home & quality of the build & insulation.

Sleeper12

https://www.boards.ie/discussion/comment/120077211#Comment_120077211

Everyone can shop around & get the cheaper tariff (if there is one). Like John G in his post, I paid 30 odd cent per KW for electricity on my last bill. You will also see electricity coming down in price later in the year. Prices are artificially high at the moment. It's a very foolish person that would select a new heating system based on the energy markets of today when electricity is temporally high. Also people simply refuse to factor in the government donations into their electricity accounts this year & last year. Doing this brings the cost per KW down.

unkel

Yes you would have to make a prediction of future energy markets, but as we have seen this can be extremely difficult / impossible to forecast. As my personal hedge against this, I have gone massive on solar PV and solar thermal, with a huge home battery and all my cars have been EVs for years

And everybody gets the government discounts, whether you heat with fossil fuels or with electricity. So these are irrelevant.

Personally I do not want to replace my gas boiler with another one when it is end of life (10 years old this year, so that time might be coming soon). I do want to go electric. In fact, I already do a lot of heating with electricity. All my water and to give you an idea, I didn't start to use gas for heating until mid November when the cold stretch hit us.

That said, I am far from convinced about full house heat pump systems and their total cost of ownership, mainly because the eye watering install costs. I will likely go a cheaper implementation of a few mini split systems (with only minimal install disruption and a fraction of the install costs), probably just 2 higher power ones, air to air only and use old skool immersion for water and mostly far IR panels for heating in the rooms with no mini split

Sleeper12

I have mini split myself in a few rooms. Used for AC more so than heat. The problem with mini split for heat is, it can be an unpleasant heat. We have an invisible barrier around our body & this helps keep heat in our bodies or on our skin. Warm air from mini split displaces the barrier. A fan in summer has the same effect. A fan in summer blows room temperature air but because it displaces the barrier around your barrier it can have a cooling effect even though the air isn't any cooler than the air around you. Warm air blown at you can have the same effect. It can actually have a cooling effect. It doesn't bother me too much but my wife doesn't like warm air from the mini split. Radiators provide a different type of heat. Convection you get from rads is more pleasant but u can get cold spots around the room as the heat bounces off the ceiling it doesn't com back & heat all the room evenly. Radiated heat from under floor heating is by far the most comfortable type of heating. The whole room is the same temperature from ceiling to floor & into every corner.

Not great for the environment but Mini split units do make a brilliant AC in the summer. ACs are far cheaper to run then people realize too

unkel

If I'd use them as air conditioner in the summer, they would run 100% on PV. Perfect combo, entirely environmentally friendly too.

Sleeper12

And soooo nice to have a little cool air on a hot summer night. 😎

unkel

https://www.boards.ie/discussion/comment/120078665#Comment_120078665

Extremely rare that I have found nights too hot (after sunset). That's one of the best things about Ireland. Cool nights and no mosquitoes 😁

But it can get very hot in the house during the day alright, I think we were pushing 30C indoors when the all time high temp record for Ireland was broken just a few miles from me last summer.

Alkers

https://www.boards.ie/discussion/comment/120077192#Comment_120077192

That is the exception in my experience, most heat pump houses have two zones (upstairs and downstairs), some have had multiple zones downstairs.

If you leave a room on frost protection, how long does it take to heat up to a comfortable temperature?

Most people with heat pumps in new builds are not experts at this kind of thing and just leave the whole house at 20C regardless, which is what I'm getting at

Ush1

https://www.boards.ie/discussion/comment/120077497#Comment_120077497

Nobody is questioning efficiency, the point is you need a minimum SCOP of around 4 to break even cost wise in most cases because gas is so much cheaper per kwh than electricity.

unkel

And a COP of 4 is very optimistic in real life. Perhaps in a passive house, but highly unlikely you can get that in most retrofitted older houses.

John.G

Based on what I paid for oil very recently, a SCOP of 2.73 would be the break even point, oil at €1.19/ltr and a SCOP of 2.38 based on my assumed cost of gas at €0.14/kwh

Ush1

Not to mention the capital outlay to get it installed and retrofitted etc...

Payback time is the question, unless you need a new boiler anyway.

Ush1

https://www.boards.ie/discussion/comment/120086262#Comment_120086262

My gas is 13c, my elec day rate is 44c, peak rate is 61c!

SycoLTH

Hi all, I recently moved to a newly renovated house with underfloor heating and a heat pump and I don't have any comparison reference numbers.

House is 150sqm, temperature is set to 18° during the day, 15° at night.

The average kwh usage is between 20 and 25 kW per day, at my current price (~0.44€ per kWh) it uses around 8€ per day.

My last bill, on the 21st of December, was 600€.

What am I doing wrong??

CoBo55

https://www.boards.ie/discussion/comment/120088030#Comment_120088030

Nothing, 44c per unit is what's killing you. BG offered me a 39.5c rate to stay with them another year, might be no harm to contact your supplier. I think unkle is being very optimistic in thinking the electricity providers are going to drop their prices to the ordinary consumer, wholesale gas prices have been dropping steadily, not a peep from the providers.

Alkers

https://www.boards.ie/discussion/comment/120088030#Comment_120088030

How well is your house holding heat?

I assume you're on a 24 hour meter? Would it be worth changing to a day/night meter, heating the house (at a much cheaper rate) overnight and letting it cool slightly during the day rather than spending full price electricity units?

John.G

https://www.boards.ie/discussion/comment/120088030#Comment_120088030

Does that include your domestic usage as well or does your HP record its own consumption?

SycoLTH

I'm nearly at the end of my year contract, time to negotiate something better, but .39 doesn't seem like a big difference.

I wouldn't know how to check if the house is holding heat, what I can say is that we lined the place with 50mm insulated boards inside, the attic is covered in pink insulation snowflakes, and even though the heating is set to 18°, the house is constantly around 20°. When we cook kitchen goes up to 23° even. All rooms are independent with their own thermostat and actuators.

I have a smart meter, I think I can get a day/night tariff with that without changing for a day/night meter, maybe that's a solution. Since yesterday I've started taking reading in the morning and in the evening, to see what the day/night usage is.

That includes domestic usage, I should reset the boiler counters and see what it is using out of those 20kw a day.

But you all agree that 25kw a day for heating and domestic usage is not too much?

CoBo55

https://www.boards.ie/discussion/comment/120089908#Comment_120089908

Jaysus I'm using more than that and that's with oil heating 😡

John.G

https://www.boards.ie/discussion/comment/120089908#Comment_120089908

25kwh/day is excellent, if you allow say a low 8kwh for domestic use, that leaves 17kwh for heating, at a COP of 3 then 51kwh/day to heat your house!.

I average around 9.0 ltr/day of Kerosene, heating on for 16hrs/day with a SE Firebird Boiler which = ~ 69kwh/day net to heat the 4 bed house, I keep bedrooms at ~ 16C, large kitchen at 18c and combined dining/living room at 18C until around 20.00 hrs and then 20C until ~ 0100 hrs the following morning.

Sleeper12

https://www.boards.ie/discussion/comment/120089908#Comment_120089908

I wouldn't have thought that your home is suitable for a heat pump based on the insulation you described.

What BER rating do you have?

I agree with others that you daily usage isn't actually that high

SycoLTH

I feel a little better, it's the first winter in this home and I got a good bill shock.

I don't know the BER rating, but before the renovations was D2. Then we retrofitted underfloor heating with 50mm floor insulation. And 50mm dry lining boards all around inside. The attic has 6 to 10 inches of that pink insulation fibers all around.

We didn't replace the windows this time around because they were already double glazed pvc.

The heat pump is a 7kva(??) Bosch.

We also have the ventilation system with heat recovery, I still don't understand how that works, but at times I can feel a little draft coming from the vents, so it's doing something.

Maybe solar panels would help, does anyone have them?

Sleeper12

50mm of wall insulation isn't much. Well it is a fair amount but not enough for a heat pump. Maybe you put 50 mm over already insulated walls. I've no idea how well those beads are insulate the attic. Usually 100mm solid foam is cut to size and fitted inside the attic joists. Then another 200mm of roll out insulation goes over that giving minimum total installation of 300mm

I would get another BER done and see what it says. BER guy will tell you exactly where you need to spend the money to improve the comfort level of your home. It's much more important to bring insulation levels up (if it's needed) before spending on solar