ground source project so far

[Servotech]

Once the ground loop has had all the heat extracted out of it by the heat pump it's quite common for the water in the loop to return back into the ground at a minus temperature.

This is why a anti-freeze solution must be used in the loop.
Servotech,

 

[mike528]

ah i see, so its a fine art to getting the right amount of pipe work in the ground.

not just chucking as much pipe in the ground as possible.

why is it a fine art then? not having enough pipe would be detrimental but to much pipe is not going to matter bar for extra cost!

 

[RigidRaider]

FWIW I have a neighbour who has done this. The two trenches across his meadow were roughly 50m long, 2m deep and 2m wide if I recall. We buried 450m of pipe in coils in those, again don't quote me; these are guesses.

Even at Christmas time the cottage was toasty warm with the floor being the only heat source. My neighbour is well aware of the danger of freezing the ground and runs the system carefully to avoid freezing. He reckons the system has become more efficient two years on as the soil has settled around the pipes. His only regret is that he installed the compressor in the utility room rather than out in the garage; it is heavily soundproofed but the motor can still be heard (or felt) around the house. He also has solar HW and PV. His total energy bill last year was £75.

 

[mike528]

FWIW I have a neighbour who has done this. The two trenches across his meadow were roughly 50m long, 2m deep and 2m wide if I recall. We buried 450m of pipe in coils in those, again don't quote me; these are guesses.

Even at Christmas time the cottage was toasty warm with the floor being the only heat source. My neighbour is well aware of the danger of freezing the ground and runs the system carefully to avoid freezing. He reckons the system has become more efficient two years on as the soil has settled around the pipes. His only regret is that he installed the compressor in the utility room rather than out in the garage; it is heavily soundproofed but the motor can still be heard (or felt) around the house. He also has solar HW and PV. His total energy bill last year was £75.

hi could you give me a rough idea how big a floor area he has and what size heat pump Kw

 

[RigidRaider]

Floor area is a small cottage, probably about as much as a 3 bed semi.

Pump is 4 kw and costs him 1 kw to run so net gain 3 kw.

 

[Norcon]

ah i see, so its a fine art to getting the right amount of pipe work in the ground.

not just chucking as much pipe in the ground as possible.

why is it a fine art then? not having enough pipe would be detrimental but to much pipe is not going to matter bar for extra cost!

To much pipework concentrated in a small area would be a problem.
Other than that oversizing the collector area shouldn't be a problem other than the extra cost.