Air source heat pump

[StrongLegs]

Hi,

I wondered if anybody might have already had an air source heat pump fitted to an older house, and could tell us how much upheaval is involved?

We live in a detatched, 30' square, 1920s house with single skin walls, and not quite enough loft insulation. We have a pyramidal roof so it's not really that much use for solar panels.

The parking round he is very difficult, so any building work involves me doing a lot of careful booking of parking spaces with bins, and periodically getting fined by the council, because booking spaces with bins is not allowed.

One side of our house is on the boundary, so if we wanted to have external insulation fitted it would be massively disruptive to our immediate neighbours and would involve them modifying their car port to make space for our house becoming a bit wider.

We're currently paying for all renewable gas and electricity so we're technically carbon neutral, but I figure we will have to get our house sorted sometime soon, at least when our current boiler packs up.

I wondered if anyone might know how much work it is to have the conversion - not from reading about it, but from having actually lived through the experience?

Would we have to move out?

Thanks!

Having investigated it, but not done it, I would say almost impossible to do in your property.

There was a recent big thread on these

@LesLavandes thanks, I'll have a dig.

@StrongLegs there are high temperature heat pumps available, they are more expensive of course, but designed specifically for older properties.

BTW natural gas isn't renewable, only electricity is currently renewable.

I just rang an installer and it seems as though maybe we could have internal insulation instead of external. Maybe that means we could have internal wall insulation on the side that is on the boundary and external on the other three sides. That would simpify things considerably.

@Daftasabroom our gas is definitely from renewables. We get it from www.greenenergyuk.com/.

Biogas is renewable and blended with natural gas.

www.nationalgrid.com/stories/journey-to-net-zero-stories/where-theres-muck-theres-gas

@Coogee yes That's what we have. I'm really chuffed with it because it brings our carbon footprint right down, alongside our not driving and not taking planes.

There's been a lot about heat pumps in the press this week, and it seems they would not be suitable for older houses unless completely renovated and insulated to the highest modern standards. So, not useful for the vast majority of homes in this country. If I were you I'd spend the money on insulation and stick with gas.

www.greenenergyuk.com/ bill are really easy to read and understand too.

They ask me to read the meters myself every time and then I submit the reading and they just bill me for the energy that I have used.

It means I don't have the weird stuff about being in credit or debit, I just pay the money and that's it done. It really simplifies things a lot.

I would really recommend them as a supplier.

@StrongLegs I stand corrected, I wasn't aware this was available to domestic customers. I know that pyrolysis of waste also counts as renewable, some of the coal fired power stations are being converted to run waste. It's not emissions free but a good start.

@Daftasabroom thanks so much for such a kind reply.

@ginghamstarfish it is absolutely true that heating our homes and hot water without gas is going to be challenging and that older properties are going to be the most inefficient. But there will come a stage I suspect when biogas cannot meet demand which will push up costs and restrict supply.

A good balanced article here:

www.wired.co.uk/article/hydrogen-uk-heating

I'd consider biomethane as a similar stepping stone but probably not a long term solution.

@Daftasabroom yes I totally agree. I was wondering if it might be a good idea to figure out what all the work is that needs done and do a little bit each year for the next ten years, so we don't go potty trying to do it all at once.

I was thinking something like this:

year 1 - internal insulation on one side
year 2 - loft insulation
year 3 - external insulation on three sides
year 4 - new radiators
year 5 - new water tank
year 6 - new air powered heating device, whatever it is
year 7 - new ridged roof with solar panels.

I looked and it is possible to buy a new eco house up in an adjacent new village, but it costs £1.8M for a detached house there, and we got our detached house for £355k. So fixing up the current house is definitely going to be cost effective.

It's quite a thought though, all the work we need to do.

I kind of like the idea of a ground source heat pump and having a 100 foot bore hole in the garden. We could get a well dug at the same time. LOL!

Thanks for the article. :-)

Insulate first along with other measures such as double glazing. That will give you a much better base from which to investigate how helpful a heat pump will be.

Similar-ish sounding house and we decided just couldn’t afford it as part of our current renovations. I have also read you really need a very insulated house, which ours is never going to be (although we have had insulation put under the slab, roof insulation and modern windows fitted).

@PeterPomegranate what sort of price is it for this kind of work? We're eligible for a £12k grant, but when I last looked the wall insulation alone was going to be £20k.

In order we did the following to 89m2 bungalow, cavities were already filled:

1. Timber floors lifted, 120mm foam insulation under joists, UFH pipes between joists, floors relayed. We did this before we moved in.
2. Second story extension effectively doubling the floor area with 200mm R32 wool batts in the timber frame and 100mm PU external, all taped for air tightness, and low emissivity reflect layer on top.
3. The roof is the same the wall, warm roof, except with an extra 200mm of R32.
4. MVHR
5. 70mm external insulation to old gable end walls.
6. 300litre vented thermal store with plate heat exchanger to provide mains pressure DHW

7 Heat pump coil in the TS 8 ASHP as funds and grants allow.

All told it has probably increased our build cost by about £15k to £20k compared to a standard build but we have future proofed our home.

@anniegun I completely agree about the insulation first. That way if heating gets pricier then we will not be in such a bad place financially as we work up to getting the rest done.

Sorry I can’t comment on likely costs we didn’t get further than establishing that the grants didn’t go very far (and looked confusing), that it would be an ugly box on the side of our house, and that there wasn’t really a track record of knowing whether they are a technology that will stand the test of time.

Husband has bad memories of his parents storage heating installed in the early 1980s.

It went on the ‘too uncertain and complicated’ pile and we have installed a new gas boiler.

I think that these technologies will only catch on when it’s something the size and shape of a boiler that you can put where the boiler used to be.

Oh sorry - do you mean for the insulation?

We were digging up the floors anyway. So it adding the insulation underneath was all bound up in that. I am hoping in particular it makes our cold front room warmer. We are also getting a chimney sweep to put a chimney balloon in (we don’t use our chimney). That’s pretty cheap! My dad said we could just stuff a pillow up the chimney …

We spent a lot of money on new windows because we wanted a certain style. So they were £25k eek.

We got a grant from the London Mayor (Ken Livingstone at the time) for cavity wall insulation at our old house. But this house is too old to have cavity walls.

In terms of how much upheaval is involved, we are living through it at the moment so I can tell you some of it. We already had the insulation sorted (1970s detached house) so it's been replacing all the radiators and having the heat pump installed. We had an oil boiler before. So far it's taken 2 weeks and we are at the stage now where it feels like the whole house has been pulled apart to get all the new pipes in the right places. There hasn't been a huge amount of stuff for the heating engineers to take away, but we have had 3 or 4 vans on the drive most days. We have only recently moved in so still need to decorate, so that isn't a huge problem for us, but the flooring has been up in some rooms, the ceiling has had to have holes cut, etc, so it will take some work to put it all back. Next month we will have solar panels fitted and that should be a breeze after this, I hope. It should be all worth it in the end, but it's been more noise and mess than I was expecting. I was naively expecting more of a 'one boiler out, another put in' sort of scenario, same with radiators... I spent more time looking at nice radiators than I did really listening to what they told me, I think!

That's impressive stuff @Daftasabroom. I don't even know what some of those acronyms mean. I'd be interested to know if you have a minute to expand the names as I suspect they're going to be in my future. :-)

@PeterPomegranate That's my worry too. Our house sometimes couldn't be heated above 14 degrees in the winter when we first got it and we've completely replaced the entire heating system. I don't want to go and end up cold again. Then again, I don't want to stand around shuffling my feet and pondering while the poles melt. That would be bad too. Hmmm.