Air Source Heating - Your opinion

[Bavarianbrit]

These airtight homes.
With tenants in our old 1895 terraced houses they moan about mold forming but some are too stupid to open the windows to get the human generated moisture out.
What happens with these new build space capsules?

 

[GlennUK]

Just thought on efficiency.

You may see figures of 5 - 6x efficiency which as i understand it means that for one unit of electricity you get the equivalent 5-6 heat units.

MY GSHP gets c. 2.6 based on actual readings. It varies little over the year as the temp of the soil the coils are buried in varies little over the year.

The same is not true of ASHP in that their efficiency varies with air temperature/humidity, and when you need the heat most, it will be operating at its least efficient time. That doesn't mean it won't heat the house (it may not, but should if properly designed) only that the cost of producing that heat will be much higher than summer.

HTH

Glenn

 

[udderlyoffroad]

Unlike a lot of posters on here, I do actually have an ASHP, because gas isn't an option.

However, the economics were slightly different for me. I got an ECO4 grant, so had the whole system installed at zero cost to me. This included insulation, PV system and ASHP and rads. The eligibility criteria are pretty loose, so it's definitely worth doing some research, as you're not obliged to go the full hog, you could just get insulation, for instance. Or get the ASHP, run it for a bit and convert/add on an oil/bio mass if you think it's too expensive to run.

So far, no issues in keeping the house sufficiently warm, and the lower heat of the larger rads is much more pleasant that roasting rads, IMO. Is it expensive to run? It can be, as electricity is expensive. But if you're on the correct tariff and have PV, should be quite economical, definitely favourable against oil. Parts of the house were built in the 1700s, by the way, so this "Can't be done in UK houses" argument is nonsense of the highest order.

I did write quite detailed thread on a certain other, pigeon-based forum about it, as I think spreading the word about the ECO4 grants is quite important amongst rural communities. I'm not sure the mods would be happy with me linking to another forum, but if you were to google my user name, along with 'ECO4' and 'pigeon' you would probably find it. It didn't exactly catch fire as a thread, as a large contingent on that particular forum are stuck in about 1960, and are still coming to terms with decimalisation.

 

[udderlyoffroad]

These airtight homes.
With tenants in our old 1895 terraced houses they moan about mold forming but some are too stupid to open the windows to get the human generated moisture out.
What happens with these new build space capsules?

Air flow in modern homes is better (as it is required to be considered by building regs) rather than cheap/nasty double glazing trying to retroactively seal up leaking victorian properties. Remember a real driver of mould is condensation, which is driven often by temperature deltas. Newer builds avoid this.

But I think I know where you're going with this, the German practice of "Lueften" needs to be embraced in the UK. Along with buying the...powerful anti mould agents from Polish shops which works better than the 'elf and safety approved rubbish on sale here.

 

[Buchan]

Interesting to read theses experiences as we are looking at air source. 1920 rubble built house, so no cavity insulation; voids under most floors and probably uninsulated copper pipes, so I suspect big heat loss there. Been quoted about 5k for refit. We have 32 solar panels so one bit of advice was to get another battery rather than export. I think it would work to keep the house warm, but the cost to run could be the clincher. Currently creating a spreadsheet to compare costs of gas v air source.

 

[Jagare]

I had a warm air pump at my old house. Kept the place warm even when it was - 20c. In my new place I have a air to water system. Three bedroom, 2 bathroom house from the 1930s. The previous owner had a wood pellet heating system put in but soon changed it to its present ,air water system. Several of the radiators are still the old type. The house does have triple glazing and is well insulated. I run the system 24/7 at 19-20c through out the winter. Even though electric in this southern part of Sweden is not the cheapest I've not found the electric bill to be overly expensive.

 

[shakey jake]

These airtight homes.
With tenants in our old 1895 terraced houses they moan about mold forming but some are too stupid to open the windows to get the human generated moisture out.
What happens with these new build space capsules?

You need a managed air flow, i have an mvhr that keeps the moisturein the air around 30% humidity. Best thing i ever installed

 

[Cyres]

A friend has just finished renovating and old cottage and added a big extension. Insulated to regs. Cavity wall and stone faced. He has fitted a big log burner with a back boiler. When running heats all house and oil CH not needed. The lounge gets pretty hot so door rarely closed. He is extremly pleased with it.
D

 

[ndt man]

My daughter had a new house built on the site of an existing property after much argument with a snot nosed kid from the planing department about replacing the existing gas boiler he /thay insisted on an air source system and it's rubbish imo. House just warm costs more than gas to run but the best bit is after the storms a couple of years ago ( no electricity ) so no air source heat pump = cold house for 2 days .

 

[udderlyoffroad]

House just warm costs more than gas to run but the best bit is after the storms a couple of years ago ( no electricity ) so no air source heat pump = cold house for 2 days .

As opposed to a gas boiler which won't work without electricity either? Granted it only needs electricity for control, rather than as its fuel source, but that difference is academic if you're dependent on the main grid to be up.

Currently creating a spreadsheet to compare costs of gas v air source.

If you're on mains gas, I'd put good money on the fact that the ASHP will not be worth the CAPEX costs. Those of us who aren't, however, it will look different

I had a warm air pump at my old house. Kept the place warm even when it was - 20c. In my new place I have a air to water system. Three bedroom, 2 bathroom house from the 1930s. The previous owner had a wood pellet heating system put in but soon changed it to its present ,air water system. Several of the radiators are still the old type. The house does have triple glazing and is well insulated. I run the system 24/7 at 19-20c through out the winter. Even though electric in this southern part of Sweden is not the cheapest I've not found the electric bill to be overly expensive.

Warm air/'central air' or air-to-air heat pumps aren't really "a thing" in UK domestic properties, and the government is mad-keen to keep it that way. Why? Because you then have air conditioning, only needed in the UK about 3 days a year, but the government is concerned that we shouldn't have nice things the load on the grid and CO2 emissions.

More generally, Scandi houses are by default far better built for heat pumps of whatever flavour. Not just because electricity costs are far lower than the UK, but houses are better insulated, and tend to be of the 'room in roof' design, and thus have large roof areas to permit decent size PV arrays.

 

[keith74]

I had air source heating installed about 4 years ago to a 1970s bungalow. It’s made sense for us at the time because the heating before was old storage heater so no matter what we went with would have involved pipe work and radiators being installed but the biggest thing was the grants that the Scottish government were giving out to get if fitted. We got a 3 bed system installed for less than £3000 and it’s been ok so far. We do have a wood burner as well which we run at nights in the winter but have the air source on most days.

It’s a completely different way of thinking about heating and takes some getting used to.

 

[Bowland blades]

I live in Orkney, heat pumps are common here due to lack of gas, especially air to water like mine with underfloor heating. My house is 10 years old, systems installed from new. As someone who had traditional heating system (gas), my personal experience is neutral at best. These systems are designed to run 24/7 ideally using temp curve to control pump running and heat output etc. Despite companies stating 3 or 4 to 1 ratios for efficiencies you have to factor in the much longer running times, especially in winter. Now my house is described as air-tight etc, also has MHVR system installed, I installed solar and batteries and can honestly say that without these supplementing energy use my heat pump is expensive to run and keep a 3 bed bungalow at 20-21 degrees. I just installed a new pump two years ago - 9 grand, not cheap.
I like the principle of them but totally agree with other comments about air tightness and thermal insulation, reality is that lots of things need to work together for maximum efficiency.
Hope my user insight helps.

If your home is built for that type of heating from the ground up they are pretty all good , if its not though ....

 

[shakey jake]

My daughter had a new house built on the site of an existing property after much argument with a snot nosed kid from the planing department about replacing the existing gas boiler he /thay insisted on an air source system and it's rubbish imo. House just warm costs more than gas to run but the best bit is after the storms a couple of years ago ( no electricity ) so no air source heat pump = cold house for 2 days .

Who ever built the house and installed the heat pump is at fault.
If i can retrofit a 60s bungalow, to airtight and almost pasivhouse standard, a new build should be better. Corners were clearly cut

 

[Bowland blades]

These airtight homes.
With tenants in our old 1895 terraced houses they moan about mold forming but some are too stupid to open the windows to get the human generated moisture out.
What happens with these new build space capsules?

If you retro do this swap using a house that has not been built from the ground up to cope ? Its simply not a great idea !

 

[shakey jake]

If you retro do this swap using a house that has not been built from the ground up to cope ? Its simply not a great idea !

Sorry dont agree, i have done this, i have basic building skills and it wasnt hard and works really well

 

[countrryboy]

Thanks, you have summarised everything that I have heard so far, so will go with oil.

Couple off things i'll add.

If ur house is pretty rural with a chance off power cuts have u considered LPG instead.
I put an LPG combi in instead of other heating for my UFH.
I think price/efficency are fairly similar between the 2.
Can use it for cooker hobs if a power cut.
Cant steal it the way u can oil.
And doesnae stink, oil tanks and boilers always smell.


My house was a compmete rebuild/ renovation.
Tried hard to plumb my log burner in to heating system but just too complicated and expensive to be worthwhile.
Also with a bigger back boiler u will most likely need a water pump to move it, so again in a power cut u cannae put ur log burner on.
I also gained an extra bedroom/office by doing away with all the gubbins for the hot water tank.

My brother built a house 7 yrs ago almost passihiv standard, was rated at an A for epc.
Its a pretty big house, he has an Air source,.
His house is always warm but i dont think that cheap to run.
He got a pretty good grant but the grant is up now and he's pricing ripping it out to put either oil or Lpg in.

To be fair the plumber did make a bit of an arse off putting it in ( he is a good plumber normally just never done air source before).
Some of the pipe work is too small a dia for air source, would of worked fine with a normal heating system. So that hasnae helped.

 

[Bowland blades]

Sorry dont agree, i have done this, i have basic building skills and it wasnt hard and works really well

I say this after a fair amount of training from the manufacturers of the kit . There are a few things going on and i hope you don't get into them ( mainly in drop off over time) . Its nothing at all about skill on the tools

 

[shakey jake]

I say this after a fair amount of training from the manufacturers of the kit . There are a few things going on and i hope you don't get into them ( mainly in drop off over time) . Its nothing at all about skill on the tools

What are these "things"
Three years in and im seeing zero issues. After 5 years i will have recouped my out lay by year 7 i will have made money thanks to the renewable grant. Ignoring running cost but thanks to solar by bills are about 50 a month.
If the air source goes pop ill buy another

 

[doigan]

If your home is built for that type of heating from the ground up they are pretty all good , if its not though ....

You would think, however compared to gas heating the system needs to run constantly, when very cold COP goes down, underfloor heating is effectively the same as storage heating and has the same drawbacks, you need to plan ahead As I said personnaly I would recommend one if you have all the other stuff too, I am fortunate and have an Octopus EV tariff, this allows me to store energy over-night, heat the house up at cheap rate etc, my annual usage is about 6000 units, about £1600 on normal tariff, but my bills are about £600 a year by having all the other stuff. Only two adults so the tariff is really important.

 

[doigan]

These airtight homes.
With tenants in our old 1895 terraced houses they moan about mold forming but some are too stupid to open the windows to get the human generated moisture out.
What happens with these new build space capsules?

Never had any signs of mould, that is due to having MHVR system