Air source heat pumps - a bit off putting, or is it just me?

[FolornLawn]

I was surprised to see how big and ugly they are.

This article shows a picture of one, and I wouldn't want it in my small garden. Also the report says people will need room for a boiler and a water cylinder.

I'm quite surprised at how negatively I feel about the new plans. There's something about having to remodel bits of my house and garden that feels like an imposition, when I happily recycle, use washable sanitary pads and kitchen roll, go without a tumble dryer etc. Is it just me?

@RIPWalter

I think if you're out all day you'd just do what we do at night and have it set to 14-15. If your home is well insulated then it should stay above this through the day on all but the coldest of weather. We are still playing around with it, but it is definitely more efficient to not keep having the temperature going up and down all the time.

This worries me though, I don't want to have to live in a house that's 14-15 degrees all the time? Presumably I can't just switch it on when I get home from work? Because they can't cope with temperature jumps, someone else said?

This sounds miserable. I'm really not a crazy person in terms of keeping my house warm, but even with sheepskin slippers, thick socks, thermal leggings, thermal long sleeved vest, dress and a woollen jumper I would still be cold at that temperature (for sitting round in the evenings, obviously it's fine outside for e.g. gardening or going for a walk).

I am totally happy to recycle but I don't think getting to a point where I have to have my rooms colder than we used to keep the place when we had no money is a great selling point for a system that costs 3x as much as the equivalent gas boiler. Even when we didn't use the heating we still had a warm front room using an open fire with coal and wood - obviously not environmentally friendly at all. But heat pumps sound like a step backwards not forwards?!

@Bogoroditse

We have an air source heat pump for hot water and heating. We are rural and the only other option is oil. It is a special one that works with existing radiators (Daikin) and it works a treat for our biggish 30s house which is reasonably well insulated. Very little noise. The only issue is that if it breaks down (which it had a couple of times each year) it can take literally weeks to get someone in to fix it. Those weeks are ruddy awful! I'm knitting a shawl with the next breakdown in mind..... it is a big beast though, tall as a tall fridge but thinner, and we do have a hot water tank and a cupboard full of pump equipment, that it just wouldn't work in a tiny flat. My DH is working on launching district heating into new estates all over the country, using waste heat from all sorts of places like call centres, sewage farms, data centres, factories etc etc. I'm guessing for urban dwellings a retrofit (which is possible) of district heat is a more practical solution. I agree the 5k incentive isn't going to incentive people to invest in a 15k pump.

It breaks down a couple of times a year??? Did I read that correctly? That seems completely unreliable.

Ours is never set that low; they're really designed to keep the house a steady temperature so you don't stick the heating on for a couple of hours, you just set the temperature you want it to be at the various times of day and leave it to get on with it. I have it a couple of degrees cooler at night for preference, but not 14! At the moment I'm WFH so it's just set to 20/21 all day

At least, that's how ours works - but it's a well insulated house so it holds heat well.

I live in a second floor flat and have no idea how I could have an air source heat pump. We have a small communal garden - would each flat have to have its own pump in the garden? Presumably they have to be attached to the building but I don't think there is enough wall space. I also have no room in my flat for a water tank.

I'm also really not keen on the idea of heating I can't control. I like to have heating on a timer to come on in morning and evening when I am at home, then off all day while I'm at work. I don't want it on all day wasting energy. Is it not possible to have one on a timer?

@StatisticallyChallenged

Ours is never set that low; they're really designed to keep the house a steady temperature so you don't stick the heating on for a couple of hours, you just set the temperature you want it to be at the various times of day and leave it to get on with it. I have it a couple of degrees cooler at night for preference, but not 14! At the moment I'm WFH so it's just set to 20/21 all day

At least, that's how ours works - but it's a well insulated house so it holds heat well.

So could I set it at 19 degrees for 90 minutes on the morning, and 3 hours in the evening? How would I get the equivalent of "gas heating not on" for the rest of the day and overnight? Presumably if I set it to 14 degrees it would cool it to 14 if it was warmer than that in my flat, thus using energy? When I am not at home I wouldn't want it to cool, I also wouldn't want it it heat, I'd just want it not doing anything.

It doesn't cool - it's not an air conditioner. If the temperature in the house is above the target temperature it just doesn't come on.

Controlling it, from that point of view, is no different to our old central heating system that had a wireless thermostat where you programmed it to suit. What you would probably find is that - because they aren't designed for a quick boost - that you would have it on more, but they're pretty economical so they don't use much that much energy just keeping the house up to temperature. At least, ours doesn't!

@FolornLawn

Thanks *@Daftasabroom*, that’s very interesting.

I was just listening to R4, where there was a discussion about this. A contributor on there referred to getting your house fully insulated. My house is about 20 years old, how do I know if it’s “fully insulated”?

I listened to an interview on R4 this morning with my mouth open. 15 weeks to install!! A load of stuff about fuses and distribution boxes. I suspected that he was using a company with little experience of installing ASHP. The first thing the guy who came to survey the house for suitabi;ity for an ASHP was that we needed to get our distribution board upgraded- which we already knew as we had been advised previously that if we wanted any additional sockets etc installing, we would need an upgrade. One of our criteria when selecting a company was a track record and a plumbing background. We saw several companies who had started as solar panel companies and moved into ASHP without a good knowledge of plumbing. We have microbore pipes and a high pressure unvented water system, so installation was more complex. My house is 23 years old, and we had to have an EPC done for the RHI payment, and we were advised that if we didn't qualify for a RHI payment we should leave the ASHP until we had improved the insulation. We were fine, we have double glazing, and cavity wall insulation and decent level of insulation in the loft- we topped up a bit after we had been here a couple of years. I suspect that a house built in accordance with Building Regs post 1998 would be OK. We had a couple of radiators replaced in rooms that had always been chilly, and they are now toasty warm.

@StatisticallyChallenged

It doesn't cool - it's not an air conditioner. If the temperature in the house is above the target temperature it just doesn't come on.

Controlling it, from that point of view, is no different to our old central heating system that had a wireless thermostat where you programmed it to suit. What you would probably find is that - because they aren't designed for a quick boost - that you would have it on more, but they're pretty economical so they don't use much that much energy just keeping the house up to temperature. At least, ours doesn't!

Ah OK thank you. Some other posters had mentioned that they cool as well as heat so had assumed they all did, but I guess some do some don't.

Interesting thread. My feeling is that as with PV & electric cars the technology will come on dramatically in a few years. Eventually I want to replace my wood burner based CH with either a much more efficient wood fuel boiler, or a heat pump but it just seems like it's sensible to wait a little & let everything move on.

In the mean time I'm spending my money on insulating my house really well (loft insulation up to current standards, internal wall insulation, replacing old / not that great double glazing units) plus I have PV that automatically heats my hot water through an immersion when it's exporting. Regardless of heating system I figure that minimises my energy use & also makes the house more comfortable.

I can say for sure I wouldn't be doing this if I were ever planning on moving though (or if I were younger & still dealing with childcare expenses etc etc) and I really don't think that we're going to get the UK housing stock insulated as it needs to be without some serious government input.

@RichardMarxisinnocent

I live in a second floor flat and have no idea how I could have an air source heat pump. We have a small communal garden - would each flat have to have its own pump in the garden? Presumably they have to be attached to the building but I don't think there is enough wall space. I also have no room in my flat for a water tank.

I'm also really not keen on the idea of heating I can't control. I like to have heating on a timer to come on in morning and evening when I am at home, then off all day while I'm at work. I don't want it on all day wasting energy. Is it not possible to have one on a timer?

We had one in East Asia when we lived in a third floor flat. The outside unit was on our balcony. It had a remote control with plenty of functions (timer, heating, cooling, drying, automatic by temperature etc).

@StatisticallyChallenged

Ours is never set that low; they're really designed to keep the house a steady temperature so you don't stick the heating on for a couple of hours, you just set the temperature you want it to be at the various times of day and leave it to get on with it. I have it a couple of degrees cooler at night for preference, but not 14! At the moment I'm WFH so it's just set to 20/21 all day

At least, that's how ours works - but it's a well insulated house so it holds heat well.

Why wouldn't you have it on 14 overnight? I would want it off overnight, the same as my gas heating so setting it to 14 degrees (my flat only very rarely gets below 16 degrees) would achieve this wouldn't it? I'm not really sure why I am worrying about this as don't think I can have one for my flat and couldn't afford one anyway. Maybe one day I might have a house and then it will be useful to know these things.

We had one in East Asia when we lived in a third floor flat. The outside unit was on our balcony. It had a remote control with plenty of functions (timer, heating, cooling, drying, automatic by temperature etc)..
Thank you. Unfortunately our flats don't have balconies so that wouldn't be an option. Interesting to know yours did do cooling.

@RichardMarxisinnocent so far, yes despite only being 3 years old and costing 17k. Utterly ridiculous and I often miss our old house's gas combi boiler... so glad we didn't pay for it, previous owner did... we are planning a full renovation soon and have debated getting a new system, not sure we would get a more reliable one though

I wouldn't have it at 14 because I don't want my house that cold, that's all - I would find that uncomfortable. No idea if this house would drop as low as that, our old place could get to single digits (as we discovered when the boiler broke down in December one year and we hit 7 degrees).

Our last two (gas) heating systems worked the same way so the setting temperatures instead of on/off bit is just normal for us. You choose the temperature you are happy with.

@EvilPea

This will be interesting for the millions of renters out there.

I don’t understand why this isn’t standard on all new builds, they should have solar panels, they should be insulated to within an inch of their lives and have heat pump heating. They shouldn’t get planning unless it’s green.

we're looking at new build houses at the moment and every single one we've considered has had a gas boiler. Totally bonkers. I get that the developers have put them in as obviously the cheapest thing to put in but the government should be forcing all new build homes to have heat pumps, solar, EV points etc.

But back to the point yeah it's out of reach for most families right now Hopefully eventually prices will come down though and with gas prices spiralling out of control, they should become more attractive from a cost as well as environmental pov. one way or another though, we'll all be paying far more for energy in the future than we previously have done.

@StatisticallyChallenged

I wouldn't have it at 14 because I don't want my house that cold, that's all - I would find that uncomfortable. No idea if this house would drop as low as that, our old place could get to single digits (as we discovered when the boiler broke down in December one year and we hit 7 degrees).

Our last two (gas) heating systems worked the same way so the setting temperatures instead of on/off bit is just normal for us. You choose the temperature you are happy with.

Thank you for explaining. I am lucky that my flat must be fairly well insulated as it virtually never gets colder than 16, so setting the thermostat to 14 wouldn't mean it was 14 in here (and cold), it would mean the heating not coming on because it's always warmer than 14. I certainly would have my heating on overnight if I lived in a home which got down to single digit temps.

I have an air source heat pump, outside unit similar size to one on that article.
My house was built to passive standards, air tight loads insulation ect if house is not airtight they are inefficient and very expensive to run so not suitable for retrofit unless lot work done to house (can't have airtight with a letterbox )
I'm very happy with mine as house built with it in mind however can see how it is not a solution for many houses.

@853ax

I have an air source heat pump, outside unit similar size to one on that article. My house was built to passive standards, air tight loads insulation ect if house is not airtight they are inefficient and very expensive to run so not suitable for retrofit unless lot work done to house (can't have airtight with a letterbox ) I'm very happy with mine as house built with it in mind however can see how it is not a solution for many houses.

How does airtight work on a summer night when you might want to have your bedroom windows open to let in some cooler air? Or indeed if you're someone who likes to have fresh air at any time of year? Or if you sometimes dry washing indoors and want yo do it by an open window? Can you not open your windows at all? Do you have any ventilation? Sorry for all the questions, just intrigued about how it works!

I live in a Victorian terrace it just wouldn't fit.

They look like the old 'wall banger' ac units when I lived in the ME years ago. Give it five years and they'll be smaller and cheaper.

@853ax snap. My house is also at passivhaus standard. @lljkk this is one is those houses with a forced air system. And @RichardMarxisinnocent I might answer some of your questions.

You can open windows easily and we do so alot! Really though, the air coming through the forced air system (MVHR) is much better as it is filtered air from outside. These houses are great for ventilation - far better than relying on air bricks.

In reality, heating happens a few days a year. Solar gain through the triple glazed windows plus cooking provides almost all the heat we need. For heat we have an heat pump in the MVHR system plus some electric underfloor heating for really extreme weather.

Heating isn't the challenge - keeping cool is. We have lots of external shading so the sun doesn't hit the glass May-August. We night purge, so open all the windows from 6-9 in the morning in the summer and get some active cooling through the MVHR as well. House temperature is normally less than 26 degrees even if it is mid 30's outside.

But really most older houses are not going to operate like this! But you can get pretty close if you consider the Enerphit standard which has been applied to Victorian terraces at least.

I accept that Enerphit is probably more significant upheaval that most people can cope with/afford. But lots of these older homes have been retrofitted with central heating, electricity and indoor plumbing since they were built and a switch to a heat pump and a bit more insulation doesn't seem that much to do in that context!

Ours is on a wall outside. Doesn't seem excessively big to me and we have a very small garden. It's not that loud either really, I only hear it if everything else is off at night and I'm in the room with that outside wall.

The house is very well insulated so it doesn't come on that much. The warmth of the radiators depends on how cold it is outside, the colder it is the hotter they are, but they are never as hot as old school radiators. The hotter radiators for a colder day is a setting, it was set differently first and the house took longer to heat up. I rarely even notice when the radiators are on tbh!

If somebody foolishly leaves an outside door open on a cold day it can take quite a while to get the temperature back up. That's the only disadvantage really. And windy but mildish weather isn't great because the outside sensor doesn't think it's cold enough to do the fast heating but it feels colder to us.

I can't really see how it's practical for houses that aren't really well insulated.

We live in an 1850's Victorian stone terrace, and I have reservations around the effect of insulation on the house- as others have said, these older houses are designed to breathe and to have air flow in order to avoid damp and condensation inside. We have problems in one of our rooms where newer gypsum plaster was used, as it hinders the air movement and we tend to get some damp in there without careful and consistent ventilation. That aside the cost does seem prohibitive- to spend around £15k on a heating system, changing radiators etc would be to spend 16-17% of what we spent on our house in the first place on a new heating system, whereas the new gas boiler we bought shortly after we moved in was £4k including fitting etc. We couldn't have afforded the £10k with the £5k subsidy, never mind the full cost. Around here, many houses are older mining terraces, relatively cheap when compared to bigger cities, with solid stone walls, and small narrow terraced gardens. I am very very pro changes to lifestyles to help the environment but cannot see how this is a feasible alternative without costs coming down- there has to be a solution, but I don't think this is it.

I think they are an excellent solution for detached houses with plenty of outdoor space and space inside for a hot water cylinder. But I can’t see how they could work for the tiny terraces in my street.

@RichardMarxisinnocent. I dry all my clothes indoors because the MVHR system takes the damp air or straight away so I don't have to worry about mould. We can have windows open in Feb on a sunny day if we want - keeping an eye on the temperature though. Temperature needs to keep very stable, the house can't do wild swings so it is always 20-22 degrees we aim for. It will lose 0.3 degree overnight in winter. If it gets cold, it can take a while to heat and vice versa. Not all pasivhaus are like that, but ours is due to construction method.

I love living in it though - it changes your life never being chilly, fresh air at all times, no harsh radiator hest. We also have hard floors and the reduction in dust has made such a difference to DH sniffles. Alot less insects come in the house too and the sound proofing is great. I will be doing my best to avoid living in a non-passivhaus again.

Heat pump for water has decent sound insulation on in, and is tucked in a plant room - but more sound insulation can be added so the noise shouldn't be a reason to put people off. MVHR is greedily sound proofed anyway.

can't have airtight with a letterbox

The letterbox is the least of our worries. You can stand up inside one of our fireplaces.