Geothermal heat pumps

[dhananjaylagwan]

I have heard that geothermal [ground source heat pumps] are highly efficient than the conventional ones.

What exactly is a ground source heat pump?

How does it function?

And mainly how it is more efficient than the conventional ones.

Please advise.

[Lowrider]

There are in fact two types of geothermal heatpumps.

One uses a well (either closed loop or open) and the other uses a closed loop running through a large area of soil.

The other heat pumps use air to remove the heat from. From 1 kg of air, when removing 10K one gets 10kJ ( air has a specific heat of 1kJ/kg*K).

Water has a specific heat of apr. 4,2 kJ/kg*K. So from 1kg and the same temperature diff one gets 42 kJ.

In order to get the same amount of heat from an air based one as that of a water based one the amount of air going through it has to be 4,2 larger. Thus a large evaporator.

Even though the water based one needs an extra pump or even two for the ground water, the amount of energie needed for this is far less then that of an air based one and the energie transfer in a plate heat exchanger is far more efficient then that of an air coil.

Hope this explains it somewhat!

[dhananjaylagwan]

hmm. ok I have a basic idea now. Thanks for the same.

Can you please elaborate a bit? one more thing how much deep do you have to go below the ground for achieving optimal performance?

Are there any limitations? Also can this system be used for cooling applications?

Also what are the effects of seasonal variations on the system?

Also can it be implemented in a temperate climate?

[nike123]

http://www.gshp.org.uk/faqs.htm

[dhananjaylagwan]

Hey thanks man! that was a really cool link. It has cleared most of my doubts.

[dhananjaylagwan]

But what are the effects of seasonal variations on the system?

[Kh1971]

Thanks Nike123, it is realy great Info

[nike123]

But what are the effects of seasonal variations on the system?

Depends on type of weld and it is much lower to insignificant in comparison with air source heat pump.
http://tinyurl.com/2dh3eo

[dhananjaylagwan]

ok fine. Thank you sir.

[Lowrider]

What about seasonal variations? Ground water is a very constant and reliable source of heat and doesn't change as much as the weather does.

In Holland we build a lot of these ranging van 200kW to 10MW and supply hot water in winter and chilled water in summer.

I could send you a schematic of a system if you send me a pm with your e-mail adress