Talk to me about air source heat pumps

[RidingMyBike]

We've just had an offer accepted on a house that needs a lot of work, including replacing an old boiler. It's been a longterm aim to have solar panels but we're also looking at an air source heat pump and had favourable comments from friends who have installed one - although they weren't on mains gas so have saved a lot not having to buy heating oil.

Any thoughts? Pros, cons? Things to watch out for?

Where are you - I suspect they will be less effective for the colder areas in the uk
How big is the house - too big and it won't give enough heat
How well insulated is the house - really needs to be top notch

How well insulated is the house - really needs to be top notch

This is the most important thing.

But you need independent advice not from an installer.

Yorkshire. It's an extended semi that needs quite a bit doing to it and we are expecting to have to do some insulation work as part of that (we'd be doing this part anyway even if we just get a replacement gas boiler). It currently has an old gas boiler and hot water tank. House is fully double glazed, some of which need replacing. Some radiators need replacing and/or moving anyway which is also a factor as we know they may need to be bigger?

Where to get independent advice from? I've found the company that the local council uses for the low income home improvements energy-saving but they're the installers!

Hi, we replaced our ancient oil boiler with an ASHP 4 years ago and have no regrets. The key is ensuring your house is really well insulated. Double glazing, CWI, loft insulation etc.

We retrofitted and did have to change some of our radiators. We also had to replace our hot water cylinder. If we had been renovating our house we would have put in underfloor heating but it's fine without it.

We used a company called AOS Heating and they were great. We had to have an EPC in order to qualify for the grant and they arranged all that for us.

The thing that struck me about them, is that they use electricity. I'd check to see how efficient they are as the rise in electric prices might be a factor. We dismissed one as we live in a 200 year old cottage and it's just not insulated enough, so we stuck with oil. Which is still going up in price, just not as much as electric

Replace double glazing, that’s needs replacing fir triple glazing

Insulate with either external or internal insulation, cavity wall insulation

Roof insulation

Look at ground ground source heating and air pump with solar panels and a battery that you could run electric heating alongside

I’d have underfloor heating

House needs to be very well insulated with BER of C1/B3 or above. Old double glazing is not enough you would need argon or other gas-filled not air.

They are most efficient with underfloor heating and need servicing every year. They are also pricey, but if you have all the above, one should work well with solar PV as a fuel source. Do change those radiators. You can find out the most suitable ones online.

I know several people who have them installed.

All have relatively modern, highly insulated properties with underfloor heating and all find they need a secondary source of heating. Two, have log burners for the living room and one an Electric fire.

One, has had major issues all winter with a system that keeps tripping out and a Manufacturer that cant resolve the issues. I guess that could happen with any boiler. The difference is that the quotes for replacing the faulty unit (7 years old) are well in excess of £8k.

My thoughts about Air Source at the moment are that it is probably an important heating system for the future but only in the right house (highly insulated with underfloor heating), preferably with the technology a little more advanced and most important of all enough trained engineers to understand the systems and able to deal with issues.

Old double glazing is not enough you would need argon or other gas-filled not air.

That's not true. Obviously if you were going to replace your windows it makes sense to buy the most efficient you can afford, but we have old (but fully functioning) double glazing, and our house is really warm.

OP, one thing you will find about ASHP is that loads of people who don't actually have one will give you loads of "advice" about how rubbish they are. Before we had ours installed, we spoke to several.people locally who had had one installed which gave us the confidence to proceed.

I think we have to stop using just one source of heating but look at complementary systems

My parents replaced an oil boiler with ASHP and they haven't needed any additional heating the last two winters.

They had to have a couple of extra radiators added but they didn't need any extra insulation (1970s house with 1990s double glazing, CWI, suspended floors). They've just had solar panels and battery storage installed.

Thank you - this is really interesting! And echoes what friends who've had it installed have said.

@EmmaGrundyForPM (excellent username BTW!) yes, my Mum is v anti us getting ASHP on what seems to be the basis of a couple of newspaper articles she's read, rather than personal experience!

We have one in our annexe (we wanted it separate from our oil fired system in the main house). It's great, very efficient. We have it on most of the time in this cold weather. It's a Daikin.
The only possible drawbacks I suppose could be that it's a little ugly on the wall and slightly noisy for a brief time when it gets up to temperature.

Ditto what others have said about insulation. We have very efficient insulation in those rooms.

We had a survey done for a ASHP for our 5/6 bedroomed mid terraced house built about 200 years ago. It came out at £15K but on top of that insulation needed at about £10K. We gave up. We also feared the greatly increased electricity costs and the disruption throughout the house.

We have a Viessman ASHP for heating and domestic hot water. It's 10 years old now. Our house was built 2012 with triple glazing and underfloor heating. You really need to be well insulated otherwise it's working hard all the time to generate heat. Ours is really noisy especially during cold days. Our neighbour has complained about it.

The newer heat pumps are supposedly quieter. Use the heat pump with photovoltaic panels if possible or solar thermal panels. We get ours serviced once a year for about 70£. Leaves can get sucked in so keep away from trees/bushes.

Every room has a temperature control and it's best to keep the heat pump on all day and night as it's more efficient that way to keep the temperature constant.

We have wet (hot water) underfloor heating (it's cheaper than electrical underfloor).

We also have a separate meter for the heat pump so we can use heat pump tarifs which can work out a bit cheaper than the standard electricity tarif. Might be worth checking that out too.

My ASHP lasted exactly 4 years. Cost £6,000 to replace and despite double glazing needs a log burner as backup in my small period property Solar panels have been a much better investment.

Would suggest getting recommendations for an ASHP I’d going ahead, and getting one with a long guarantee.

I think they only work well in modern well- insulated homes.

We had one installed two months ago. We love it. Really nice just having normal heating all the time rather than two big blasts of heating per day with dips in between like you have with a gas system. We had to change two radiators but no biggy. Is your mum a telegraph reader by any chance? They put so many anti-ASHP articles out, it's outrageously biased, I don't know they can be so swayed by their investors to change the narrative on needing sustainable heat sources. It's not cheap but it is great. Oh and its very very quiet, the models have changed really recently. You can only hear it outside, not inside. Don't listen to people who don't have one, especially if they read the telegraph!

According to my engineer bf they are rubbish. I think I would look into insulation. Our apartment is heavily insulated and the difference is remarkable. Apparently solar panels are not that great anymore in terms of selling back electricity.

You could contact an energy assessor who specialises in retro fitting properties. Also look on which.co.uk as they have plenty of information on all aspects of energy saving and possible costs. You probably need to joking which but it’s only £10pm.

Join, not joking.

Don’t point it at your neighbours house … our neighbours have one (it’s new) and it is quite noisy, esp on the v cold, still nights

We have a well-insulated house though only double-glazed albeit good quality windows. The installer did careful calculations to make sure the heat pump was not too small but also not too big- because they can be inefficient if the wrong size. Actually even though our house is a large detached, based on our gas bills and insulation we got one of the smallest on the market and it's been great. I love the fact the heating is on low most of the time - very comfy and even, and some rooms that used to be cold seem warmer now, perhaps they have had a chance to warm up with the long hours of steady heat.

DH reckons we are spending a little bit less on heating/hot water than we were before when we were on gas. Electric cooker too so we have lost the gas standing charge as well. A huge amount of the performance is down to the skill of the installer. But when you are renovating is the ideal time. Its definitely the future. I think gas is going to go up faster than electricity especially with the current situation.