Air-source heat pumps - are they good/crap?
Discussion
Arrivalist said:
Yep, agree with all that and something I ll be keeping a very close eye on when working on design with architect.
No doubt will be looking at solar too as there are some great systems now that seem fully integrated with the roof covering.
My question was just trying to understand the benefit of cheap tariffs overnight for ASHP when I suspect it s not doing much. My understanding may be completely wrong though.
My guess is that your building will still be around when cheap overnight tariffs are history.No doubt will be looking at solar too as there are some great systems now that seem fully integrated with the roof covering.
My question was just trying to understand the benefit of cheap tariffs overnight for ASHP when I suspect it s not doing much. My understanding may be completely wrong though.
If you have a massive concrete slab, you can heat it more at night, but the reality tends to be IMHO that people want their homes warmer in the evening.
For a new build I would be looking at plenty of solar and a battery.
Shnozz said:
I m still confused as to the air sourced heat pump terminology and uk pricing.
I ve had air con in Spain for donkeys years that heats in winter and cools in summer. Seems to be the same product without the fancy title. And without the price. My bedroom and office ones were about £400 and my massive open plan downstairs one about £600.
Do your aircon units provide your hot water and central heating to radiators/underfloor? I'd guess not. That's the difference.I ve had air con in Spain for donkeys years that heats in winter and cools in summer. Seems to be the same product without the fancy title. And without the price. My bedroom and office ones were about £400 and my massive open plan downstairs one about £600.
Arrivalist said:
Andeh1 said:
ASHP are muuuuuch better suited with cheap energy tariffs /smart tariffs, then solar.
As I've said, our ASHP is brilliant with the 6p kwh we pay from midnight to 6am with a smart tariff.
But you re paying normal tariff rates outside of those hours, when you need the house warm, so can you explain how that helps?As I've said, our ASHP is brilliant with the 6p kwh we pay from midnight to 6am with a smart tariff.
Honest Q as I m aiming to do a self build in the next few years and am trying to learn as much as I can.
If the house was less well Insulated then 50/50 6p and 27p gives you an average of say 15p...3x COP (ie 300% efficient vs gas boiler)..... Still beats gas.
My maths is prob wrong, but hopefully it gives you an idea. Combine it with PV and it only helps further.
Edit.. Maths!
Edited by Andeh1 on Friday 13th February 16:32
clockworks said:
Arrivalist said:
Andeh1 said:
ASHP are muuuuuch better suited with cheap energy tariffs /smart tariffs, then solar.
As I've said, our ASHP is brilliant with the 6p kwh we pay from midnight to 6am with a smart tariff.
But you re paying normal tariff rates outside of those hours, when you need the house warm, so can you explain how that helps?As I've said, our ASHP is brilliant with the 6p kwh we pay from midnight to 6am with a smart tariff.
Honest Q as I m aiming to do a self build in the next few years and am trying to learn as much as I can.
I effectively turn the heating off at 19:30, and back on again at 23:30.
While the heating is off, room temperatures drop by 2 or 3 degrees on a really cold day. By morning they are back up again.
Note that I'm in a 1960's dormer bungalow, EPC E. A new build will lose less heat during the "off" period, so you could probably turn it off a lot earlier
Andeh1 said:
Arrivalist said:
Andeh1 said:
ASHP are muuuuuch better suited with cheap energy tariffs /smart tariffs, then solar.
As I've said, our ASHP is brilliant with the 6p kwh we pay from midnight to 6am with a smart tariff.
But you re paying normal tariff rates outside of those hours, when you need the house warm, so can you explain how that helps?As I've said, our ASHP is brilliant with the 6p kwh we pay from midnight to 6am with a smart tariff.
Honest Q as I m aiming to do a self build in the next few years and am trying to learn as much as I can.
If the house was less well Insulated then 50/50 6p and 27p gives you an average of say 25p...3x Cop Still beats gas.
My maths is prob wrong, but hopefully it gives you an idea. Combine it with PV and it only helps further.
I have written on here quite a bit as its front and centre for me right now , deciding what to do next .
I have a solar proposal and an ASHP proposal after a survey .
Both assume there is overnight or off peak electricity savings over the next 10 years , albeit without that it doesn't beat gas for us . It actually is only near to gas with the cheap rate built in for 6 hours in 24.
What if cheap rate / overnight tariffs disappear . Whist they attract balancing of the grid , once more houses have batteries and if cars can act as batteries, surely the grid will get balance anyway ? Are we taking a chance that cheap rate and or in addition the rate you get for selling back remain .
If I have seen a fair bit of conjecture on this subject , what I do know is how economics works in practice not in theory . As more of us go electric for more stuff , I think the price may well go up .
I have a solar proposal and an ASHP proposal after a survey .
Both assume there is overnight or off peak electricity savings over the next 10 years , albeit without that it doesn't beat gas for us . It actually is only near to gas with the cheap rate built in for 6 hours in 24.
What if cheap rate / overnight tariffs disappear . Whist they attract balancing of the grid , once more houses have batteries and if cars can act as batteries, surely the grid will get balance anyway ? Are we taking a chance that cheap rate and or in addition the rate you get for selling back remain .
If I have seen a fair bit of conjecture on this subject , what I do know is how economics works in practice not in theory . As more of us go electric for more stuff , I think the price may well go up .
cliffords said:
I have written on here quite a bit as its front and centre for me right now , deciding what to do next .
I have a solar proposal and an ASHP proposal after a survey .
Both assume there is overnight or off peak electricity savings over the next 10 years , albeit without that it doesn't beat gas for us . It actually is only near to gas with the cheap rate built in for 6 hours in 24.
What if cheap rate / overnight tariffs disappear . Whist they attract balancing of the grid , once more houses have batteries and if cars can act as batteries, surely the grid will get balance anyway ? Are we taking a chance that cheap rate and or in addition the rate you get for selling back remain .
If I have seen a fair bit of conjecture on this subject , what I do know is how economics works in practice not in theory . As more of us go electric for more stuff , I think the price may well go up .
Cheap rate tarrifs have been around for as long as I can remember - Economy 7, etc.I have a solar proposal and an ASHP proposal after a survey .
Both assume there is overnight or off peak electricity savings over the next 10 years , albeit without that it doesn't beat gas for us . It actually is only near to gas with the cheap rate built in for 6 hours in 24.
What if cheap rate / overnight tariffs disappear . Whist they attract balancing of the grid , once more houses have batteries and if cars can act as batteries, surely the grid will get balance anyway ? Are we taking a chance that cheap rate and or in addition the rate you get for selling back remain .
If I have seen a fair bit of conjecture on this subject , what I do know is how economics works in practice not in theory . As more of us go electric for more stuff , I think the price may well go up .
I guess it's possible that guaranteed 5 or 6 hours cheap rate overnight might go, but intelligent/flexible tarrifs will become more popular - there will be times when there's a surplus from renewables on the grid, and nowhere to store it centrally. Selling it cheap (but still covering their costs) to consumers to store on hardware that they have paid for probably makes more sense than the suppliers building their own storage for occasional use.
I just had my "cheapest" day ever on Intelligent Go with a heatpump and a 12KW house battery (no solar).
Battery charged up as normal overnight, which keeps the house running until after lunchtime.
Plugged the car in when we got back from the supermarket at noon, and Octopus decided to start charging it shortly afterwards.
As soon as the rate drops, the battery switches to charge mode. 2 hours of cheap electric, battery almost full again.
Cheap rate bonus slot ends, battery takes over supplying the house.
Another cheap hour in the evening, battery charged again, and my evening shower (10KW electric unit) was at cheap rate too.
Including charging the car, we used 47KWh that day, just 1 hour on the grid at peak rate. Total cost £4.11. Take off the standing charge, and that's 7.6p a unit.
A heatpump with an EV and a relatively small house battery can really make sense
Battery charged up as normal overnight, which keeps the house running until after lunchtime.
Plugged the car in when we got back from the supermarket at noon, and Octopus decided to start charging it shortly afterwards.
As soon as the rate drops, the battery switches to charge mode. 2 hours of cheap electric, battery almost full again.
Cheap rate bonus slot ends, battery takes over supplying the house.
Another cheap hour in the evening, battery charged again, and my evening shower (10KW electric unit) was at cheap rate too.
Including charging the car, we used 47KWh that day, just 1 hour on the grid at peak rate. Total cost £4.11. Take off the standing charge, and that's 7.6p a unit.
A heatpump with an EV and a relatively small house battery can really make sense
Skodillac said:
Shnozz said:
I m still confused as to the air sourced heat pump terminology and uk pricing.
I ve had air con in Spain for donkeys years that heats in winter and cools in summer. Seems to be the same product without the fancy title. And without the price. My bedroom and office ones were about £400 and my massive open plan downstairs one about £600.
Do your aircon units provide your hot water and central heating to radiators/underfloor? I'd guess not. That's the difference.I ve had air con in Spain for donkeys years that heats in winter and cools in summer. Seems to be the same product without the fancy title. And without the price. My bedroom and office ones were about £400 and my massive open plan downstairs one about £600.
ASHP is an air to water heat pump. This means the hot water it outputs can be used to either heat UFH, rads or a hot water cylinder.
Heating via water gives radiated heat which is much more effective and deep penetrating than heating via convection (air) alone.
AdamV12V said:
"Air con" is an air to air heat pump. So only able to blow warm or cool air into a room.
ASHP is an air to water heat pump. This means the hot water it outputs can be used to either heat UFH, rads or a hot water cylinder.
Heating via water gives radiated heat which is much more effective and deep penetrating than heating via convection (air) alone.
Oh come on!ASHP is an air to water heat pump. This means the hot water it outputs can be used to either heat UFH, rads or a hot water cylinder.
Heating via water gives radiated heat which is much more effective and deep penetrating than heating via convection (air) alone.
“Water-based systems, particularly underfloor heating, can provide a more even and comfortable heat distribution than blown warm air systems, because of larger radiant surfaces and lower air movement.”
That’s a (largely) defensible re-statement of what you wrote.
But “…much more effective and deep penetrating heat” is empty marketing language…!
My technical knowledge is zero. I just don’t understand Kwph. Even watching YouTube videos with all this information on heat pumps confuses me.
I said previously I live in a 2000 detached four bedroom. Combi boiler to heat the house.
The octopus heat pump installations seem ok in price with the government grant. BUT two seperate gas engineers who have attended my property both said stick with a combi for now. One was a British Gas engineer who came to give my boiler an annual service. So yeah it’s probably in his interest to tell people to stick to boilers.
The second guy came out to install a towel radiator in my bathroom from an independent company.He seemed to know a fair bit about heat pumps and I think knew how to install them. He said wait a few years to see how the technology progresses before switching.
In addition to this , my mortgage is due for renewal next year. Halifax will pay up to £2000 if you have a heat pump installed if you have remortgaged to them within a year. Other banks do similar pay backs.
So in theory if I did go ahead with a heat pump install, with the government grant and a £2000 pay back from the Halifax , it would cost next to nothing..
However the water tank installation is still a concern of mine. Having to find somewhere to put it would be a nightmare in my opinion, as we have no airing cupboards in our house.
I said previously I live in a 2000 detached four bedroom. Combi boiler to heat the house.
The octopus heat pump installations seem ok in price with the government grant. BUT two seperate gas engineers who have attended my property both said stick with a combi for now. One was a British Gas engineer who came to give my boiler an annual service. So yeah it’s probably in his interest to tell people to stick to boilers.
The second guy came out to install a towel radiator in my bathroom from an independent company.He seemed to know a fair bit about heat pumps and I think knew how to install them. He said wait a few years to see how the technology progresses before switching.
In addition to this , my mortgage is due for renewal next year. Halifax will pay up to £2000 if you have a heat pump installed if you have remortgaged to them within a year. Other banks do similar pay backs.
So in theory if I did go ahead with a heat pump install, with the government grant and a £2000 pay back from the Halifax , it would cost next to nothing..
However the water tank installation is still a concern of mine. Having to find somewhere to put it would be a nightmare in my opinion, as we have no airing cupboards in our house.
Arrivalist said:
Who s actually paying for the £2000 pay back? I can t see the mortgage companies suddenly developing a charitable side.
Probably you and I 
Seems quite prevalent, with various stipulations from the different banks.
https://www.heatgeek.com/articles/save-big-on-your...
I did ask ChatGPT
chatgpt said:
So is it “free money”?
Not really.
It’s usually:
A marketing cost
Funded from overall mortgage margins
Partly supported by cheaper green funding
Strategically justified by lower expected risk
Not really.
It’s usually:
A marketing cost
Funded from overall mortgage margins
Partly supported by cheaper green funding
Strategically justified by lower expected risk
Simpo Two said:
Arrivalist said:
Partly supported by cheaper green funding.
What does that actually mean? All sounds like dodgy b
ks to me.
It means money taken from other taxpayers, probably via energy bills as the UK has some of the most expensive energy prices in the world.What does that actually mean? All sounds like dodgy b
ks to me.Being overtly provocative.
It means using tax payers money to provide subsidised EV charging,and or subsidised ASHP installs with subsidised electricity, whilst the elderly die of hypothermia in the UK every winter.
I d imagine the heat pump companies have simply increased the prices of installations because of the government grants of 7.5 k.
Our energy bills are so expensive because of these government grants . It s the tax payers funding these heat pumps being installed.
Our energy bills are so expensive because of these government grants . It s the tax payers funding these heat pumps being installed.
Edited by Rogerout on Friday 20th February 00:06
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