3 ms·

400% efficiency? Is that even possible? (Did AI write this?)

thehappypm 4y ago
Yes, you might want to do some research on it. The core idea is that you aren’t using 1 unit of electrical energy to create 1 new unit of heat energy. You are using 1 unit of electrical energy to capture several units of pre-existing heat energy from the environment and pump it indoors.
sbradford26 4y ago
So the term efficiency with heat pumps typically refers to COP Coefficient of Performance. It a measure of how many watts of heat you are able to pump per given watt of electricity used. So 400% would be a COP of 4.0 which is definitely possible with air source heat pumps in milder weather and ground source heat pumps in pretty much any weather.
Nihilartikel 4y ago
If I can spend 1 joule to transfer two joules of enthalpy from outside to inside, then that is 200% efficiency. Burning 1 joule of gas would give you 1 joule of heat in a perfect world. That is what a non pump does.
- vikingerik 4y ago
  Where exactly does that first spent joule go, thermodynamically speaking? Is it also converted to heat within the electromechanicals of the heat pump?
  - SigmundA 4y ago
    Yes so not only are you capturing heat from the environment you are turning electricity into heat in the compressor, both are delivered as heat to the interior. This is an advantage compared to cooling where you must reject both the interior heat and the heat of compression.
  - kenmacd 4y ago
    To add to the other answer, if you calculate the absolute limit on performance for heating and cooling using the Carnot cycle, the 'heating' case is always going to be '1' higher than the cooling case, because you also get to use the 'work' heat.
aaronax 4y ago
More technically it would be a coefficient of performance of 4, which in some frames of reference is like 400% efficiency.
SigmundA 4y ago
https://en.wikipedia.org/wiki/Coefficient_of_performance https://en.wikipedia.org/wiki/Coefficient_of_performance
nicoburns 4y ago
If you measure the efficiency of heat output relative to the electrical input power, then yes. The trick is that there's actually another input: latent heat in the environment. But given that this is abundant and freely available we don't usually bother to include that in our calculations.
kortilla 4y ago
Yes, because a heat pump is taking the heat from the outside environment and moving it into your house. You’re only paying the “transportation cost” and not the actual cost to generate heat. The heat was generated by the sun.

Yes, you might want to do some research on it. The core idea is that you aren’t using 1 unit of electrical energy to create 1 new unit of heat energy. You are using 1 unit of electrical energy to capture several units of pre-existing heat energy from the environment and pump it indoors.

sbradford26 4y ago

So the term efficiency with heat pumps typically refers to COP Coefficient of Performance. It a measure of how many watts of heat you are able to pump per given watt of electricity used. So 400% would be a COP of 4.0 which is definitely possible with air source heat pumps in milder weather and ground source heat pumps in pretty much any weather.

Nihilartikel 4y ago

If I can spend 1 joule to transfer two joules of enthalpy from outside to inside, then that is 200% efficiency. Burning 1 joule of gas would give you 1 joule of heat in a perfect world. That is what a non pump does.

vikingerik 4y ago
Where exactly does that first spent joule go, thermodynamically speaking? Is it also converted to heat within the electromechanicals of the heat pump?
- SigmundA 4y ago
  Yes so not only are you capturing heat from the environment you are turning electricity into heat in the compressor, both are delivered as heat to the interior. This is an advantage compared to cooling where you must reject both the interior heat and the heat of compression.
- kenmacd 4y ago
  To add to the other answer, if you calculate the absolute limit on performance for heating and cooling using the Carnot cycle, the 'heating' case is always going to be '1' higher than the cooling case, because you also get to use the 'work' heat.

aaronax 4y ago

More technically it would be a coefficient of performance of 4, which in some frames of reference is like 400% efficiency.

SigmundA 4y ago

https://en.wikipedia.org/wiki/Coefficient_of_performance https://en.wikipedia.org/wiki/Coefficient_of_performance

nicoburns 4y ago

If you measure the efficiency of heat output relative to the electrical input power, then yes. The trick is that there's actually another input: latent heat in the environment. But given that this is abundant and freely available we don't usually bother to include that in our calculations.

kortilla 4y ago

Yes, because a heat pump is taking the heat from the outside environment and moving it into your house. You’re only paying the “transportation cost” and not the actual cost to generate heat. The heat was generated by the sun.