heating your house with cold theory
Discussion
This is just theorising so bear with me:
I asked earlier about heating a portacabin with renewable energy, and the suggestions were:
solar cells
solar heating
underground heating
all rely on heat radiation to work of course.
It got me thinking if there is any way we could extract energy from the cold instead and at first discounted it unless we find some freely available material that is solid in heat and evaporates in the cold (a reverse steam engine type thing).
Anyway, water expands when it freezes right?
so what if we were to get a cylinder, fill it with water and put a piston on top, the piston drives some heavy duty hydraulic generator. (i sway heavy duty since the freezing process is painfully slow so we would need to rely on the awesome power of freezing rather than the freeze/defrost cycle frequency) (so we'd be extracting torque, rather than bhp in engine comparison?)
so this liquid expands, activates these massively stiff turbines, they produce electricity and heat your home. shut the insulating flap and the liquid defrosts, driving the generators again.
could that possibly work in a much refined form or is the concept so deeply flawed that I should get my coat?
I asked earlier about heating a portacabin with renewable energy, and the suggestions were:
solar cells
solar heating
underground heating
all rely on heat radiation to work of course.
It got me thinking if there is any way we could extract energy from the cold instead and at first discounted it unless we find some freely available material that is solid in heat and evaporates in the cold (a reverse steam engine type thing).
Anyway, water expands when it freezes right?
so what if we were to get a cylinder, fill it with water and put a piston on top, the piston drives some heavy duty hydraulic generator. (i sway heavy duty since the freezing process is painfully slow so we would need to rely on the awesome power of freezing rather than the freeze/defrost cycle frequency) (so we'd be extracting torque, rather than bhp in engine comparison?)
so this liquid expands, activates these massively stiff turbines, they produce electricity and heat your home. shut the insulating flap and the liquid defrosts, driving the generators again.
could that possibly work in a much refined form or is the concept so deeply flawed that I should get my coat?
syncro. said:
You'll be needing this -> 
and a copy of Thermodynamics for dummies (try Amazon)
In my defence, it all just came to me within 10 seconds, then i had another 45 to think about whilst i was typing. and a copy of Thermodynamics for dummies (try Amazon)Though, why wouldn't it work in short? I am not exatly extraccting energy from nothing, the colds is coming from somwhere too and I am just playing with the temperature differential.
Stirling engines work on temperature differentials. Presumably you could rig one up to take advantage of the warmer temperature underground vs the colder temperature of the surfaceenvironment. And make it work in the opposite circumstances when the envionment was warmer than the temperature of the ground.
What you describe is very similar to how some steam engines work. The motive force comes from steam in one direction and atmospheric pressure in the other, when the steam on the other side of the piston cools and condenses.
http://www.mgsteam.btinternet.co.uk/engdev.htm
http://www.mgsteam.btinternet.co.uk/engdev.htm
Edited by marshalla on Tuesday 5th January 17:14
Our new house uses some sort of magic mumbo jumbo to take heat out of the air, kind of like a reverse air conditioner (exactly like it in fact)
All I know is, the two units round the back of the garageblow out BLOODY cold air, and despite Dad explaining it to me a few times, I can't see the benefit of a system that takes heat out of the air in winter, as you'd get more heat in summer, and less in winter!
I may have started something though, he came back from the library yesterday with a couple of thermodynamic books...
All I know is, the two units round the back of the garageblow out BLOODY cold air, and despite Dad explaining it to me a few times, I can't see the benefit of a system that takes heat out of the air in winter, as you'd get more heat in summer, and less in winter!
I may have started something though, he came back from the library yesterday with a couple of thermodynamic books...
Magog said:
Stirling engines work on temperature differentials. Presumably you could rig one up to take advantage of the warmer temperature underground vs the colder temperature of the surfaceenvironment. And make it work in the opposite circumstances when the envionment was warmer than the temperature of the ground.
Isn't that a geothermal heat pumpvoyds9 said:
Magog said:
Stirling engines work on temperature differentials. Presumably you could rig one up to take advantage of the warmer temperature underground vs the colder temperature of the surfaceenvironment. And make it work in the opposite circumstances when the envionment was warmer than the temperature of the ground.
Isn't that a geothermal heat pumpI prefer my idea:
You get a really big blue snooker ball, fire it into space, then accelerate it back towards you really fast so the blue colour turns into microwaves. You absorb the microwaves with a big dish and use them to power something, then decelerate the ball and repeat the cycle.
A 'double-expansion' version of this invention is to keep the ball moving past you at high speed such that the blue colour turns into infra-red; again you collect the radiation but this time as it recedes. This way, for every stopping and reacceleration of the ball, you get two helpings of energy.
All I need is a way to power the ball. Perhaps some of the energy gathered could be re-transmitted back to it. Or maybe keep some of it back to start with, thereby avoiding transmission losses.
You get a really big blue snooker ball, fire it into space, then accelerate it back towards you really fast so the blue colour turns into microwaves. You absorb the microwaves with a big dish and use them to power something, then decelerate the ball and repeat the cycle.
A 'double-expansion' version of this invention is to keep the ball moving past you at high speed such that the blue colour turns into infra-red; again you collect the radiation but this time as it recedes. This way, for every stopping and reacceleration of the ball, you get two helpings of energy.
All I need is a way to power the ball. Perhaps some of the energy gathered could be re-transmitted back to it. Or maybe keep some of it back to start with, thereby avoiding transmission losses.
Mr.Jimbo said:
Our new house uses some sort of magic mumbo jumbo to take heat out of the air, kind of like a reverse air conditioner (exactly like it in fact)
All I know is, the two units round the back of the garageblow out BLOODY cold air, and despite Dad explaining it to me a few times, I can't see the benefit of a system that takes heat out of the air in winter, as you'd get more heat in summer, and less in winter!
I think you mean an air source heat pump.All I know is, the two units round the back of the garageblow out BLOODY cold air, and despite Dad explaining it to me a few times, I can't see the benefit of a system that takes heat out of the air in winter, as you'd get more heat in summer, and less in winter!
http://www.energysavingtrust.org.uk/Generate-your-...
In summary:
clicky linky said:
An air source heat pump extracts heat from the outside air in the same way that a fridge extracts heat from its inside. It can extract heat from the air even when the outside temperature is as low as minus 15° C.
isee said:
syncro. said:
You'll be needing this -> and a copy of Thermodynamics for dummies (try Amazon)
In my defence, it all just came to me within 10 seconds, then i had another 45 to think about whilst i was typing. and a copy of Thermodynamics for dummies (try Amazon)Though, why wouldn't it work in short? I am not exactly extracting energy from nothing, the colds is coming from somewhere too and I am just playing with the temperature differential.
I'd be tempted to say the efficiency of a machine that turns 10mm of movement from the expansion of ice into a few thousand revolutions of a generator will be extremely low, 10s of percent probably.
There's also the issue of where you're getting your heat from.
syncro. said:
I'd be tempted to say the efficiency of a machine that turns 10mm of movement from the expansion of ice into a few thousand revolutions of a generator will be extremely low, 10s of percent probably.
Don't forget that ice expands with incredible force - so any mechanism could be very highly geared...What we really need is some kind of nuclear generator, extracting the energy from a few specks of uranium. But the lefties still wouldn't like it.
Simpo Two said:
syncro. said:
I'd be tempted to say the efficiency of a machine that turns 10mm of movement from the expansion of ice into a few thousand revolutions of a generator will be extremely low, 10s of percent probably.
Don't forget that ice expands with incredible force - so any mechanism could be very highly geared...What we really need is some kind of nuclear generator, extracting the energy from a few specks of uranium. But the lefties still wouldn't like it.
Trevelyan said:
Mr.Jimbo said:
Our new house uses some sort of magic mumbo jumbo to take heat out of the air, kind of like a reverse air conditioner (exactly like it in fact)
All I know is, the two units round the back of the garageblow out BLOODY cold air, and despite Dad explaining it to me a few times, I can't see the benefit of a system that takes heat out of the air in winter, as you'd get more heat in summer, and less in winter!
I think you mean an air source heat pump.All I know is, the two units round the back of the garageblow out BLOODY cold air, and despite Dad explaining it to me a few times, I can't see the benefit of a system that takes heat out of the air in winter, as you'd get more heat in summer, and less in winter!
http://www.energysavingtrust.org.uk/Generate-your-...
In summary:
clicky linky said:
An air source heat pump extracts heat from the outside air in the same way that a fridge extracts heat from its inside. It can extract heat from the air even when the outside temperature is as low as minus 15° C.
Better still, in the summer I just press a button on the remote and it all works back to front and cools the room to a nipple perking 16c.
Air sourced heat pumps can be very useful, in heating mode they can give out 4 or 5 times the amount of energy (as heat) as they consume in electricity.
In some of my underfloor heating systems I can heat a 3 bedroomed house using the same power as a single fan heater (2.5kW).
However they do use electricity which has to made and transported somehow, and the colder it is outside the less efficient the heat pump is.
Yes, you can use the ground as a source of heat, but this involves high capital cost - and a conventional heat pump fitted to an existing house only really heats one room (not the whole house).
New Zealand has relatively cheap electricity (much of it hydro etc), and we don't have freezing temperatures during the day so air sourced units are very suitable - however their use in the UK would be much more limited but there is still plenty of potential.
In some of my underfloor heating systems I can heat a 3 bedroomed house using the same power as a single fan heater (2.5kW).
However they do use electricity which has to made and transported somehow, and the colder it is outside the less efficient the heat pump is.
Yes, you can use the ground as a source of heat, but this involves high capital cost - and a conventional heat pump fitted to an existing house only really heats one room (not the whole house).
New Zealand has relatively cheap electricity (much of it hydro etc), and we don't have freezing temperatures during the day so air sourced units are very suitable - however their use in the UK would be much more limited but there is still plenty of potential.
Lord Flathead said:
Simpo Two said:
Soooo - if these air-source heat pumps are so good, why doesn't the Govt subsidise them? That would really help their green target, no?
Because they enjoy taxation from our fuel costs.
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