They do, though I think the prospects of using them as a sole source of water heating for domestic purposes seem iffy to me. Everyone is getting them but realistically you would need an alternative alongside that for hot domestic supply.
I have one for a pool. It is a Waterco like this one. Waterco - Electroheat Heat Pump Swimming Pool Heater HD - Sole UK Distributor Paramount Pools Ltd - YouTube This vid explains how it works. It is effectively an air conditioner working backwards, taking heat out of the ambient air, using a heat exchange and refrigerant, using the fridge elements to dissipate the cold you are effectively "taking out" of the water you are warming up (i know that is an inaccurate characterisation of the physics).
You pay for the cost of running the fan and running a pump to move the water through it. That is a lot cheaper than the cost of an electric element heater or gas or oil. The unit cost me about £4k 12 years ago and we have only had two service issues. One coil issue and one thermostat. So about £150 of service costs. I have also replaced the water pump over that period - about £600.
If you used one for the house, you'd get warm water cheap but if you wanted hot water you'd need something beyond that. They struggle to work if air temperatures get too low and they won't provide hot hot water. But the most expensive part of warming water is getting it from cold to warm. Warm to hot (in an immersion cylinder or through a boiler) is relatively cheap and quick. I suppose domestic supplies take the water through the air source, into a cylinder or through a boiler back into the cylinder and from there to taps and showers.
No they heat all water. They have an immersion heater in them anyway to run an anti-bacterial heat up once every couple of weeks. You can set the temp for the system so that it is hotter, but obviously that will engage more immersion use.
If you are getting one I would also get well positioned solar panels and a battery. You can then time shift energy draw from the grid as well as using the energy from the solar panels to run the heat pump and charge the battery.
It needs to be properly sized and sited somewhere that's not in the shade, you shouldn't get one before you upgrade all your insulation, and ideally you make the pipes running to your heating system wider and/or install UFH when you put it in.
They work perfectly well. Mine is running 1-2kWh of electricity a day for hot water (48C) and 4-6kWh for 270m2 UFH heating (19.5C room temp) in current weather. This will obviously go up when weather gets colder.
TBH just get the biggest battery you can and pull in electric on a cheap rate tariff to run the heat pump/other stuff when electric is expensive. There's an Octopus tariff, Agile, where you can actually be paid to take electricity off the grid and paid loads to discharge into it. I think Tesla Powerwalls can "learn" how to make the most of that arbitrage.
Muttley - not sure that's quite right about it being easier to heat water further once it's warm (should take the same energy to heat water by 1c regardless of starting temp).
Are you not anywhere that has different electricity tariffs depending on time of use Economy 7 style? If not then don't bother with the battery but ASHP "works" and unless you think gas prices will come down, or don't get any subsidy, then I think an obvious choice.
Muttley - not sure that's quite right about it being easier to heat water further once it's warm (should take the same energy to heat water by 1c regardless of starting temp).
You actually get increased rates of evaporation if there's any headspace so it will get harder to heat as it gets warmer. But I think if you can efficiently heat it to eg 40°c then inefficiently hearing it another 10c° as and when you need to might be efficient.
yeah Mr Large the point I didn't address was that cold infrastructure (pipes, tanks) mean when you start heating domestic water there is more loss until you actually have heated the pipes etc so they then act as a thermal insulator and the depletion is reduced. Then the second phase of warming water actually - in practical terms rather than the physics of warming water - is more efficient. A hot water system without a non-return valve gives you a lot of cold water from the hot tap before the hot runs hot. The infrastructure wastes the heat.
Okay, interesting. I'm no expert so will take your word on it but in a closed system I would have thought the water in the pipes and the pipes themselves should largely be at the same temp at rest and should therefore increase at the same rate and that each degree the water needs to be warmed would mean absorption by the pipe of the same amount of energy - regardless of the temp. Obviously if the pipe is below the water temp (e.g. any part that runs outside) then that's different.
You know how a fridge employs a heat pump to collect warmth from the air in the fridge and pump it out via the radiator piping on the back of the fridge?
Now put the fridge in an open window and open its door. Warmth is extracted from the air outside and the room warms up because of the radiator piping.
It seems weird to us that you can do this even when the air outside is really cold but as long as you use a fluid that freezes well below 0º it works OK.
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My experience is limited to only heating water to 27C but yes definitely works and much less expensive than doing the same thing with an oil boiler.
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yes
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They do, though I think the prospects of using them as a sole source of water heating for domestic purposes seem iffy to me. Everyone is getting them but realistically you would need an alternative alongside that for hot domestic supply.
I have one for a pool. It is a Waterco like this one. Waterco - Electroheat Heat Pump Swimming Pool Heater HD - Sole UK Distributor Paramount Pools Ltd - YouTube This vid explains how it works. It is effectively an air conditioner working backwards, taking heat out of the ambient air, using a heat exchange and refrigerant, using the fridge elements to dissipate the cold you are effectively "taking out" of the water you are warming up (i know that is an inaccurate characterisation of the physics).
You pay for the cost of running the fan and running a pump to move the water through it. That is a lot cheaper than the cost of an electric element heater or gas or oil. The unit cost me about £4k 12 years ago and we have only had two service issues. One coil issue and one thermostat. So about £150 of service costs. I have also replaced the water pump over that period - about £600.
If you used one for the house, you'd get warm water cheap but if you wanted hot water you'd need something beyond that. They struggle to work if air temperatures get too low and they won't provide hot hot water. But the most expensive part of warming water is getting it from cold to warm. Warm to hot (in an immersion cylinder or through a boiler) is relatively cheap and quick. I suppose domestic supplies take the water through the air source, into a cylinder or through a boiler back into the cylinder and from there to taps and showers.
Ours is not noisy
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I think you'd use them to heat the water in the radiators rather than the water you use to bath etc, no?
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No they heat all water. They have an immersion heater in them anyway to run an anti-bacterial heat up once every couple of weeks. You can set the temp for the system so that it is hotter, but obviously that will engage more immersion use.
If you are getting one I would also get well positioned solar panels and a battery. You can then time shift energy draw from the grid as well as using the energy from the solar panels to run the heat pump and charge the battery.
It needs to be properly sized and sited somewhere that's not in the shade, you shouldn't get one before you upgrade all your insulation, and ideally you make the pipes running to your heating system wider and/or install UFH when you put it in.
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0
They work perfectly well. Mine is running 1-2kWh of electricity a day for hot water (48C) and 4-6kWh for 270m2 UFH heating (19.5C room temp) in current weather. This will obviously go up when weather gets colder.
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So I’ve already got the underfloor heating, but no real room for sole panels
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TBH just get the biggest battery you can and pull in electric on a cheap rate tariff to run the heat pump/other stuff when electric is expensive. There's an Octopus tariff, Agile, where you can actually be paid to take electricity off the grid and paid loads to discharge into it. I think Tesla Powerwalls can "learn" how to make the most of that arbitrage.
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Err I’m not in the uk…..
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Muttley - not sure that's quite right about it being easier to heat water further once it's warm (should take the same energy to heat water by 1c regardless of starting temp).
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Are you not anywhere that has different electricity tariffs depending on time of use Economy 7 style? If not then don't bother with the battery but ASHP "works" and unless you think gas prices will come down, or don't get any subsidy, then I think an obvious choice.
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0
You actually get increased rates of evaporation if there's any headspace so it will get harder to heat as it gets warmer. But I think if you can efficiently heat it to eg 40°c then inefficiently hearing it another 10c° as and when you need to might be efficient.
They do work very well in warmer climates.
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yeah Mr Large the point I didn't address was that cold infrastructure (pipes, tanks) mean when you start heating domestic water there is more loss until you actually have heated the pipes etc so they then act as a thermal insulator and the depletion is reduced. Then the second phase of warming water actually - in practical terms rather than the physics of warming water - is more efficient. A hot water system without a non-return valve gives you a lot of cold water from the hot tap before the hot runs hot. The infrastructure wastes the heat.
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They do work - of course they do - it is a fridge in reverse.
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Okay, interesting. I'm no expert so will take your word on it but in a closed system I would have thought the water in the pipes and the pipes themselves should largely be at the same temp at rest and should therefore increase at the same rate and that each degree the water needs to be warmed would mean absorption by the pipe of the same amount of energy - regardless of the temp. Obviously if the pipe is below the water temp (e.g. any part that runs outside) then that's different.
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0
You know how a fridge employs a heat pump to collect warmth from the air in the fridge and pump it out via the radiator piping on the back of the fridge?
Now put the fridge in an open window and open its door. Warmth is extracted from the air outside and the room warms up because of the radiator piping.
It seems weird to us that you can do this even when the air outside is really cold but as long as you use a fluid that freezes well below 0º it works OK.
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