Air Source Heat Pump?

[AdamMGEV]

Ok so I have solar, I have Ev cars, now I'm looking to get an Air Source Heat pump.

I have a new build built this year so we'll insulates, and I have an LPG gas boiler.

Is a Heat pump worth it? Air or ground? I see grants have gone up to 7,500.

Any advice?

 

[dragon2611]

Aren't octopus meant to be releasing a high temp heat pump in Decemeber?
This ones interesting to me as it sounds like it might work with microbore piping, I'd very much like to get shot of the gas boiler but at the same time haivng the whole house pulled apart to redo the plumbing isn't something thats pratical at the moment.

 

[AdamMGEV]

Ive had a quote from Octopus for £3048 after the 7.5k has been taken off. This includes everything.

Seems like a good quote as a firm quoted me about 7k after the grant but they said Octopus use crap pumps.... anyone had a Air Source heat pump fitted from Octopus?

Thanks

 

[dragon2611]

Ive had a quote from Octopus for £3048 after the 7.5k has been taken off. This includes everything.

Seems like a good quote as a firm quoted me about 7k after the grant but they said Octopus use crap pumps.... anyone had a Air Source heat pump fitted from Octopus?

Thanks

I'd wait as their new cosy6 one launches soon.

 

[Alb]

I think they are fitting Daikin Heat Pumps.

 

[AdamMGEV]

I think they are fitting Daikin Heat Pumps.

Are they no good?

 

[Alb]

I'm not an expert in this area but I believe they are a respected manufacturer.

 

[johnb80]

Ive had a quote from Octopus for £3048 after the 7.5k has been taken off. This includes everything.

I would snatch their hand off, LPG is horrendously expensive as a form of heating.

Seems like a good quote as a firm quoted me about 7k after the grant but they said Octopus use crap pumps.... anyone had a Air Source heat pump fitted from Octopus?

Octopus us Daikin heat pumps, a very well known make from a respected company, a quality item.

You mention you have solar, what sort of size of panels / inverter / battery? they all work so well with a heatpump if they have the capacity.

 

[Tweed98]

Ok so I have solar, I have Ev cars, now I'm looking to get an Air Source Heat pump.

I have a new build built this year so we'll insulates, and I have an LPG gas boiler.

Is a Heat pump worth it? Air or ground? I see grants have gone up to 7,500.

Any advice?

What sort of a house are you in?

Current heat pumps put out low temperatures (about 45°) so you need larger radiators than the gas/oil boilers as the water temperature is lower so the emitter needs more surface area. If you currently have single rads a simple swap over to double doubles (two emiters with two waffles between may work. Better yet would be wet underfloor heating, you get a much better spread of heat (I had electric U/F heating until it got too expensive to run) and it is just better as all of your walls become useful. Downside you'll have to break out the existing screed or lift the existing floor boards, either way a lot of work and money.
Due to the lower temperature and lower power of the heat pumps you have to leave them running 24/7 ideally at a constant temperature as they don't have the grunt to boost the temperature in your house quickly.
The M&E engineer who did a heat pump seminar at work for us said it also has to be carefully designed and picked for your house as a too-weak heat pump is as bad as a too-powerful heat pump. This engineer said he didn't think heat pumps were the right choice for much of the existing housing stock. The Scandinavians bolster their heat pump heating with log burners which due to clean air laws, lack of chimneys and terraces/apartments isn't always practical in the UK.
Also if you are planning an extension you'd be better off waiting until that is done or you'll wind up getting hit for a new heat pump as well as build costs.
How good are your windows? Air leakage is an absolute killer for low-temperature systems/efficiency. I replaced the knackered old first-generation double glazing that was nearly as old as me (interestingly only one pane had blown) with triple-glazed UPVC windows, FYI it was a £40 uplift over double glazed. Even with the trickle vents, the improvement is vast. It was cooler upstairs with the 40° day we had last year than the 30° days we had the year before.
You may need to to insulate the walls and loft as heat out needs replacing.
Could do more but have to work.

 

[Robf]

I did a complete renovation of an older (1950s) detached house. As the house was completely sealed (well as far as possible) and very well insulated, we installed a MHR system that incuded a heat pump Specialized in ventilation systems - Genvex. Heating was helped with some u/floor electric in the wet rooms and a wood burning stove. It all worked reasonably well, but system had problems with external temps below 6C. I modified incoming air with some air from loft (it was a hot loft) which helped. Problem was that exhaust temps were well below freezing point and heat pump fins would freeze up with exhaust air condensation, causing the system to reverse to melt ice, I note that they now have air pre-heat which would help this, but increase electrical costs.
Note, This was an air to air system, with ducts installed during renovation, its the healthiest house for fresh air that I have ever lived in.

 

[Tweed98]

MVHR is something I would have added. No point sealing your house when you need air to breathe!

 

[AdamMGEV]

I would snatch their hand off, LPG is horrendously expensive as a form of heating.


Octopus us Daikin heat pumps, a very well known make from a respected company, a quality item.

You mention you have solar, what sort of size of panels / inverter / battery? they all work so well with a heatpump if they have the capacity.

I have 19 405w panels and two 5kw batteries and a 5kw inverter

What sort of a house are you in?

Current heat pumps put out low temperatures (about 45°) so you need larger radiators than the gas/oil boilers as the water temperature is lower so the emitter needs more surface area. If you currently have single rads a simple swap over to double doubles (two emiters with two waffles between may work. Better yet would be wet underfloor heating, you get a much better spread of heat (I had electric U/F heating until it got too expensive to run) and it is just better as all of your walls become useful. Downside you'll have to break out the existing screed or lift the existing floor boards, either way a lot of work and money.
Due to the lower temperature and lower power of the heat pumps you have to leave them running 24/7 ideally at a constant temperature as they don't have the grunt to boost the temperature in your house quickly.
The M&E engineer who did a heat pump seminar at work for us said it also has to be carefully designed and picked for your house as a too-weak heat pump is as bad as a too-powerful heat pump. This engineer said he didn't think heat pumps were the right choice for much of the existing housing stock. The Scandinavians bolster their heat pump heating with log burners which due to clean air laws, lack of chimneys and terraces/apartments isn't always practical in the UK.
Also if you are planning an extension you'd be better off waiting until that is done or you'll wind up getting hit for a new heat pump as well as build costs.
How good are your windows? Air leakage is an absolute killer for low-temperature systems/efficiency. I replaced the knackered old first-generation double glazing that was nearly as old as me (interestingly only one pane had blown) with triple-glazed UPVC windows, FYI it was a £40 uplift over double glazed. Even with the trickle vents, the improvement is vast. It was cooler upstairs with the 40° day we had last year than the 30° days we had the year before.
You may need to to insulate the walls and loft as heat out needs replacing.
Could do more but have to work.

My house was only built this year so good all round, no underfloor heating though but very well insulated

 

[Exdro]

Ok so I have solar, I have Ev cars, now I'm looking to get an Air Source Heat pump.

I have a new build built this year so we'll insulates, and I have an LPG gas boiler.

Is a Heat pump worth it? Air or ground? I see grants have gone up to 7,500.

Any advice?

We put in an ASHP in Dec ‘21 and haven’t regretted it. Yes it costs more to run when outside temps are less than 7 degrees, but so does gas or oil. It’s just that you can’t easily measure gas usage. We’ve never run out of hot water, the radiators are hot enough that they are uncomfortably hot to keep your hand on. Recently fitted solar panels have meant that all heating, hot water and car charging has bee less than £2.00 per day on average since April . Can be over £.7.00 if major car charge is carried out.
Modern radiators, wide bore piping and adequate space both inside and outside the house is needed as well as good insulation and draught proofing. We benefitted from both a grant and RHI which gives us £1600.00 a year back for 7 years.
Make sure that the plumber fits all pipes tidily, not like hand knitting and good luck. Get a survey done and don’t overspec the pump.

 

[thesustainabilitygeek]

Aren't octopus meant to be releasing a high temp heat pump in Decemeber?
This ones interesting to me as it sounds like it might work with microbore piping, I'd very much like to get shot of the gas boiler but at the same time haivng the whole house pulled apart to redo the plumbing isn't something thats pratical at the moment.

Heat pumps work with microbore piping anyway. I have ten mm microbore in this house and the heat pump doesn't struggle. The installer fitted a second circulating pump to make absolutely sure (£30?). I can also confirm that the heat pump is almost inaudible, much quieter than next door's modern boiler and that having the full set of EV, solar PV, house battery, heat pump and a wife who enjoys energy trading is currently worth £3,900 a year in savings compared to burning fossils and that the initial investment will be paid off inside eight years. Given how much installation costs have dropped (I would now get change from £4k for an octopus installation) payback should be even quicker. And when was the last time a fossil boiler or vehicle paid for itself? Absolutely fabulous technology and I can see why the fossil industry and legacy car makers are bricking it.

 

[kevinji]

I have had heat pump and new HW cylinder installed by Octopus and after the grant it only cost me £620. I cannot praise octopus highly enough. They were great. The system really works with modern well insulated properties such as our house which is insulated better than building regs. The hot water cylinder heats up between 3 and 4 and heat pump only uses 1 to kWh per night at 9p per kWh for the hot water.

 

[Exdro]

I have had heat pump and new hw cylinder installed by Octopus and after the grant it only cost me £620. I cannot praise octopus highly enough. They were great. The system really works with modern well insulated properties such as our house which is insulated better than building regs. The hot water cylinder heats up between 3 and 4 and heat pump only uses 1 to KWH per night at 9p per kWh for the hot water.

So refreshing to hear some positive feedback on heat pumps from someone who actually has one. We’ve been happy with ours.

 

[Tweed98]

So refreshing to hear some positive feedback on heat pumps from someone who actually has one. We’ve been happy with ours.

I think it depends on how they are installed and designed. If lots of people are wanting them inevitably some will contract a cowboy or a well meaning plumber without the correct training and skillset and wind up with bad results. Just like any wet heating system or any building works thinking about it really!
I'm waiting to see how the one in my Mums new place works. Its a new build timberframe granny annexe my Aunt and Uncle built for her after a couple of life set backs and I saw the building going up and it looked like it was insulated and built properly. It has an air->water heat pump with wet underfloor heating to all the rooms and she has a log burner in the corner of the living room on the bedroom wall. She's out in the sticks so no air problems but a bit more exposed and a little cooler micro-climate than in towns.

 

[Exdro]

I think it depends on how they are installed and designed. If lots of people are wanting them inevitably some will contract a cowboy or a well meaning plumber without the correct training and skillset and wind up with bad results. Just like any wet heating system or any building works thinking about it really!
I'm waiting to see how the one in my Mums new place works. Its a new build timberframe granny annexe my Aunt and Uncle built for her after a couple of life set backs and I saw the building going up and it looked like it was insulated and built properly. It has an air->water heat pump with wet underfloor heating to all the rooms and she has a log burner in the corner of the living room on the bedroom wall. She's out in the sticks so no air problems but a bit more exposed and a little cooler micro-climate than in towns.

Sounds as though you’ve had sound advice. Similar set up to mine except we bailed at the expense of ripping up our concrete floor to install wet UFH. Put electric UFH instead, run at night rate. Hope you’ll be pleased.

 

[Tweed98]

When my uncle was renovating his house, he went with electric on a large (60m² ish) floor even though I'd spoken to a screed company and got a spec for repairing the existing flooring once the pipe runs had been cut.

He soon found out that the electric floor was expensive to run and wound up retrofitting wall-mounted radiators.

Nowadays you can get half inch pipe bases that get tiled over making it easier to retrofit.

 

[Bob77]

We put in an ASHP in Dec ‘21 and haven’t regretted it. Yes it costs more to run when outside temps are less than 7 degrees, but so does gas or oil. It’s just that you can’t easily measure gas usage. We’ve never run out of hot water, the radiators are hot enough that they are uncomfortably hot to keep your hand on. Recently fitted solar panels have meant that all heating, hot water and car charging has bee less than £2.00 per day on average since April . Can be over £.7.00 if major car charge is carried out.

That (bolded part) doesn't sound very efficient. Heat pumps work best at lower temperatures. I had one fitted last year and the bedroom radiators upstairs are only pleasantly warm to the touch - certainly in moderately mild weather like we currently have. (Downstairs we have full UFH.)

Do you run your heat pump with weather compensation mode, i.e. the water temperature rises as the outdoor temperature drops? A lot of installers (mine included) leave the ASHP cranked right up to 50C or even 55C flow temperature so that people don't complain their rads aren't getting hot, but that's not the best way to run them.