- Thread starter shobo
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No, but I did want to and looked into the details of what was required about 10 years ago.
The reason I didn't go ahead at that time was because ground-source heat pumps were only really viable to be used with underfloor heating systems and I didn't wan't to mess with all my old pamment floors. They couldn't efficiently get their output heat high enough to work with radiators unless the number and / or size of the radiators were vastly increased over what is required with oil fired heating.
I believe underfloor heating is still the main option with heat pumps.
The reason I didn't go ahead at that time was because ground-source heat pumps were only really viable to be used with underfloor heating systems and I didn't wan't to mess with all my old pamment floors. They couldn't efficiently get their output heat high enough to work with radiators unless the number and / or size of the radiators were vastly increased over what is required with oil fired heating.
I believe underfloor heating is still the main option with heat pumps.
88v8
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Our neighbours up the lane spent a fortune on a ground-source system, loops under a 2 acre field, socking great pump.
Then they put a wood floor over it. Quite mad.
The running costs are ginormous.
But they have a warm floor.
If you're contemplating it for economy, factor in a 5% return on the capital you'll be laying out, and minus that off the supposed annual savings, then work out your payback period.
Only worthwhile imho if you'll be replacing a floor anyway, and depending on the age of the property the floor may need to be limecrete which isn't cheap, and then you have to be happy with a stone/tile floor.
Ivor
Then they put a wood floor over it. Quite mad.
The running costs are ginormous.
But they have a warm floor.
If you're contemplating it for economy, factor in a 5% return on the capital you'll be laying out, and minus that off the supposed annual savings, then work out your payback period.
Only worthwhile imho if you'll be replacing a floor anyway, and depending on the age of the property the floor may need to be limecrete which isn't cheap, and then you have to be happy with a stone/tile floor.
Ivor
george2019
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Where do you get 5% return on capital??
RHI does help a lot with heat pumps.
RHI does help a lot with heat pumps.
Gareth Hughes
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is the question specifically about listed buildings, or about old buildings more generally?
If the latter, there should be little difference in potential performance, since listing does not (in itself) confer a special extra degree of coldness to a building.
If the query is about consent rather than performance, it's generally something that will need planning permission as well as LBC, but I have certainly supported granting permission for air-source heat pumps on or adjacent to listed buildings, where they can be located discreetly (ditto solar panels). Unlikely to be supported if the only place to put the unit is prominently on the front elevation.
Whay your conservation officer's view on the matter is likely to be is something only you can find out, however.
If the latter, there should be little difference in potential performance, since listing does not (in itself) confer a special extra degree of coldness to a building.
If the query is about consent rather than performance, it's generally something that will need planning permission as well as LBC, but I have certainly supported granting permission for air-source heat pumps on or adjacent to listed buildings, where they can be located discreetly (ditto solar panels). Unlikely to be supported if the only place to put the unit is prominently on the front elevation.
Whay your conservation officer's view on the matter is likely to be is something only you can find out, however.
88v8
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george2019 said:
The place I usually recommend; preference shares specifically BWRA Bristol Water and NWBD Natwest (others are available) and bonds especially BOI Bank of Ireland.
All yielding better than 6% (six) in an ISA.
As with any stock market investment, capital may be at risk.
Failing to take account of the opportunity cost of invested capital is just self-deception when calculating payback period on insulation and heating.
Not that payback is everything, but something to think about.
Those same neighbours of ours were without heating last week when the heat pump broke, and were making long faces about the upcoming bill.
I sometimes think it should be called an eat pump, because that's what it does with their money.
Ivor
Flyfisher
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‘eat pump’ :lol:
When planning the heating for our house, which had only open fires, I considered a ground source heat pump because they were the most efficient at the time and we are fortunate to have plenty of space around the house for the underground pipe work. But the efficiency of such systems 10 years ago was touted as around 300% and my other option was to install mains gas, which is around 3x cheaper per kWh than electricity. So I decided against spending 5-figure sum on a system that would be no cheaper to run than a mains gas system. No doubt the economics will change in the future but I think that will take decades by which time almost any heating system would require a major revamp anyway.
When planning the heating for our house, which had only open fires, I considered a ground source heat pump because they were the most efficient at the time and we are fortunate to have plenty of space around the house for the underground pipe work. But the efficiency of such systems 10 years ago was touted as around 300% and my other option was to install mains gas, which is around 3x cheaper per kWh than electricity. So I decided against spending 5-figure sum on a system that would be no cheaper to run than a mains gas system. No doubt the economics will change in the future but I think that will take decades by which time almost any heating system would require a major revamp anyway.
Flyfisher
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Yes 300%, though no new physics required.
What this means is that for 1kW of electricity used, there is 3kW of heat generated. I suppose 'generated' is not strictly accurate, better to say that 3kW of heat is moved from the outside ground (in this case) and into the house. It's basically a refrigerator in reverse; cooling the outside ground and dumping the heat into the house rather than cooling a small box and dumping the extracted heat outside. Hence the name 'heat pump'.
What this means is that for 1kW of electricity used, there is 3kW of heat generated. I suppose 'generated' is not strictly accurate, better to say that 3kW of heat is moved from the outside ground (in this case) and into the house. It's basically a refrigerator in reverse; cooling the outside ground and dumping the heat into the house rather than cooling a small box and dumping the extracted heat outside. Hence the name 'heat pump'.
Flyfisher
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As far as the heat pump is concerned the input is 1kW of of electrical energy and the output is 3kW of heat energy. Sounds like 300% to me. How would you describe it?
Flyfisher said:
Best case assuming 100% efficiency in transfers, your inputs are 3kW of ground heat from the outside, plus 1kW of electrical energy to move the heat from the outside to the inside, so 4kW in for 3kW out, so 75%.
Now once you start factoring in losses for the pump, losses on pipework etc, you'll be lucky to break 50% so realistically to get 3kW of heat out you're probably needing to take at least 5kW out of the ground
Flyfisher
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. . . then there are the losses involved during generation of the electricity used to run the pump, plus all the embedded energy required for manufacturing the pump machinery, not to mention all the energy required to install the ground loops. All that should put the energy payback time well into the next century. :wink:
Meanwhile, back on planet Earth, the 5kW needed from the ground is effectively free so the only running cost is the 1kW of electricity for which you get back 3kW of heat, which is a 300% efficiency for the user.
I guess that's the difference between marketing and physics. :lol:
Meanwhile, back on planet Earth, the 5kW needed from the ground is effectively free so the only running cost is the 1kW of electricity for which you get back 3kW of heat, which is a 300% efficiency for the user.
I guess that's the difference between marketing and physics. :lol:
88v8
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Flyfisher said:
Just as well you're not running Tesla. they'd have gone bust by now
It seems there are very few installers, and they are all accredited to operate the RHI scheme.
I hadn't been looking at RHI, and didn't even know it existed, but since its out there, I would apply for it - BUT, it seems I would need an EPC to qualify, but since my cottage is 1600s and listed I might struggle to get a meaningful EPC or one at all, so far installers are telling me that therefore I won't be eligible.
I hadn't been looking at RHI, and didn't even know it existed, but since its out there, I would apply for it - BUT, it seems I would need an EPC to qualify, but since my cottage is 1600s and listed I might struggle to get a meaningful EPC or one at all, so far installers are telling me that therefore I won't be eligible.
george2019 said:
The rolling annualised growth of my investments over the last few years - mainly OEICs in a highly diverse range of geographical areas, sectors and currencies - by selling at highs and waiting for underperforming sectors to start performing - currently stands at 24.8%
Thankyou all,
My purpose is to compare the costs of installing and operating an oil heating system (gas is unavailable) against an ASHP system in a cottage which has only ever had electric heaters.
Capital costs seem very similar.
Can't be precise, but I estimate that the cost of electricity in operating an ASHP, though big in terms of what one might expect from an appliance, will be less than the cost of burning oil.
I've had an acknowledgement from the council that they wouldn't be concerned about the impact inside my cottage of installing pipes and radiators for an oil system - I wonder if the same applies for a heat pump system. The heat pumps are physically small, and can be fairly remote from the building, so they may not be interested in 'calling in' a ASHP system installation.
My purpose is to compare the costs of installing and operating an oil heating system (gas is unavailable) against an ASHP system in a cottage which has only ever had electric heaters.
Capital costs seem very similar.
Can't be precise, but I estimate that the cost of electricity in operating an ASHP, though big in terms of what one might expect from an appliance, will be less than the cost of burning oil.
I've had an acknowledgement from the council that they wouldn't be concerned about the impact inside my cottage of installing pipes and radiators for an oil system - I wonder if the same applies for a heat pump system. The heat pumps are physically small, and can be fairly remote from the building, so they may not be interested in 'calling in' a ASHP system installation.
Flyfisher
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shobo said:
You shouldn't have any difficulty in obtaining an EPC, after all it's a legal requirement when selling or renting a property so there are plenty of people out there who can provide one. Whether or not it is 'meaningful' - ie accurate - for a 1600s cottage is another matter, given that EPC surveys seem to be 'tick box' affairs carried out in minutes.
The real problem will be getting an EPC in the bands required to qualify for the RHI scheme. I think the property has to be in one of the top four bands, but I'm not absolutely certain.
Flyfisher
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shobo said:
Here's some interesting info on the cost per kWh of various fuels: https://www.confusedaboutenergy.co.uk/index.php/domestic-fuels/fuel-prices
Using their figure of 5.6 p/kWh for bulk heating oil and 17.6 p/kWh for electricity you would need an ASHP to be around 310% efficient to have equal running costs to bulk oil. This seems eminently reasonable so we could conclude that the running costs would be about the same.
Using their figure of 8.8 p/kwh for Economy7 electricity makes the ASHP numbers look much better, though it's unlikely you'd want to run the heating overnight. We're on a flat tariff and pay about 14.5 p/kWh for electricity, making the ASHP cheaper to run than a bulk oil system (equal cost would be at around 260% efficiency).
But it's all a bit marginal and of course energy prices are constantly changing, so perhaps the cheapest capital cost should be the decider? It's certainly reasonable to assume that fossil fuels are only ever going to increase in price but what about electricity? Even 'green' electricity looks likely to remain expensive in the foreseeable future given the way governments seem to like loading the price to pay for various 'eco-initiatives'. Plus, with talk about banning gas boilers in new homes from 2025 and the rise of electric cars, electricity demand is likely to increase pretty fast in the near future, which will do little to bring the cost down.
Remember those heady early days of nuclear power with its promise of 'energy too cheap to meter'? yeah, right!
PS: Interesting to see from that info how house coal remains the cheapest source of heat.