AIBU that Air Source Heat Pumps don't work in an old house?

[Pearandavocado]

I have bought an old cottage in the country and the EPC is very poor. It needs heating and the general consensus from local heating engineers is that an air source heat pump wouldn't work as it wouldn't get warm enough for the cottage and I need an oil installation (no gas in area). They have said all windows need replacing and the solid 45cm walls need insulating plus obviously plenty of loft insulation.

I don’t know how to vote with your poll, but we had the same with our 1900s house. Had various people look into it, did various efficiency improvements but concluded heat pump couldn’t work. We settled for lots of insulation above and below and a wood burning stove in lounge.

Plus point is, my house is lovely and cool in this heat, where some people are sweltering away!!

They are correct. A heat pump will not work unless the house is well insulated. They work by putting out a small amuont of heat constantly. Fine if the house is well insulated but not much use if the heat is disapearing out of the windows and walls faster than the pump can provide it.

That's one of the major issues affecting take up of this technology. There need to be decent grants to incentivise doing to the work to make installing one worthwhile. Or use something else. Our boiler's hydrogen ready and there are test projects ongoing for this.

Pretty much the same scenario with my 1900s house, too.

The air source heat pump would cost more than the oil and that's including the grant. Also, does it cost a lot to run because of the pump being on permanently and electricity cost being so high?

It’s not just a question of insulation, you also need pipes to the radiators to be a bigger diameter with an ASHP. They also only heat to a certain number of degrees above the ambient temperature so if the area you live in is regularly in minus figures and you like it roasty toasty then you’re better with oil. We’ve got a new external oil boiler and the house is warmer than it’s ever been, we rarely need to light the stove to top up the heat now.

That’s correct. A heat pump works at quite low temperatures and for it it to do the job the house needs to be virtually airtight. Double if not tripe glazing and all walls, floors and ceilings insulated. You will also need to install a ventilation system, so running ducting in every room . It just not suited to old houses, despite all the

It depends… with radiators probably it won’t work, with wet underfloor heating it might.

We have an old farmhouse - solid stone walls (no insulation), single-glazed leaded light windows in stone mullions and have a ground-source heat-pump (GSHP). It works OK - not dramatically cheaper than oil, but probably no worse either. We supplement a bit with log-burning stoves, but the GSHP does the majority of heating and hot water.

There's loads of information about people's experiences with this on YouTube.

Houses need to be well insulated in order for the heating to be effective, as its main function is to try to maintain a constant temperature.

We live rurally with no mains gas locally in an old stone cottage and received a government grant for work to be carried out to install heat pump due to a number of reasons: the age and construction of the cottage, the fact that oil boilers are being phased out and we can’t get mains gas. Air source is seen to be a cleaner and more sustainable way to heat your home.

A survey was carried out to calculate heat loss etc and we agreed for the work to be carried out, as our oil boiler was dirty and smelly and was on its way out anyway.

It was a major upheaval as our old oil boiler and water tank needed to be removed, heat pump boiler installed inside and large fan unit installed outside. All heating pipes throughout the house needed to be replaced, which meant floors in every room had to be ripped up and radiators were changed over to the compatible style and in some rooms, additional ones added.

On top of this, all walls that were external walls, had thick insulated boards added to them on the inside, which were then skimmed and painted. This did make each room slightly smaller though, as each board is very thick.

Our loft was also insulated and solar panels were installed on our roof. Luckily, our windows and
doors were all relatively new and didn’t need replaced.

We would have had to have replaced our boiler eventually, so this did save us a fortune on that work. We didn’t anticipate just how much of a disruption all the work would cause over a period of several weeks and we still need to replace some of the flooring that had to be ripped up to access the pipes.

The end result has taken a bit of getting used to - unlike other types of central heating using gas / oil, this setup doesn’t heat instantly - it takes a while to get up to temperature - once it reaches temperature, it will be cosy though, but doesn’t get super hot.

Be very careful. My friends electric bills sky rocketed when she put one in.
Much older house and not air tight.
She definitely regrets it.

Thank you for all your replies, it does appear as I suspected that an air source heat pump just isn't going to heat the cottage sufficiently. Also, the extra electricity bills to run it. It's all very well the government wanting everyone to move over to this kind of heating but just isn't realistic considering so much of the housing stock in the UK is old and not suitable for it. Also, with solid stone walls of 45cm thickness which are meant to be breath I don't particularly want to put board all over them so they aren't breathable.

Thank you for this thorough description of what is needed, it's very helpful

We have a Victorian stone farmhouse, we put in solid wall insulation, triple glazing and wet underfloor heating with a ground source air pump.

Before the refurbishment our oil was stolen on a regular basis.

Our house is lovely and warm, our electricity bills are admittedly high. If we were doing it again we would look at installing solar panels as well to offset some of the electricity usage.

It is doable if you want to do it.

We know four families with older (pre-1900) properties who have ASHPs (including one in a wooden house rural Sweden). They all say they're happy with their heat pumps and I can vouch that their houses are warm in winter. I think they all have good loft insulation but none has done wall insulation.

Edwardian end terrace here.

We had our broken gas boiler replaced with a heat pump. We also had double glazing and another layer of loft insulation. All rads replaced.

House was toasty last winter for the first time in 17 years but it did need the whole package for it to work.

We also had solar panels done at the same time.

You are not being unreasonable (YANBU). The engineers are giving you honest advice, which is rare!
Heat pumps run at a much lower temperature (around 45°C) compared to oil boilers (around 70°C). If you have solid stone walls and old windows, the heat will leak out faster than the pump can put it in, and you will be freezing and paying a fortune in electricity.
I would stick with the oil boiler unless you plan to spend £20k+ on internal wall insulation first.
Have a look at your property on https://homecheckup.co.uk - it shows the specific "Heat Demand" (in kWh per year) for the property. If that number is high, a heat pump will struggle. It also lists the specific order you should do the insulation upgrades in (e.g. do the loft before even thinking about the windows).
Go with the oil for now. You can always upgrade later if you insulate the walls.