No, they found a frozen area. That is not 'Permafrost'.
It was due to , at that time, not knowing the design
requirements for the loop. Of course, these have since been analysed
with a great degree of accuracy and predictablity.
Horeshit. You propose a closed 'reservoir', which it is not.
The area the loop is in contact with is in turn in contact with the
entire planet, and heat is constantly being transferred in whichever
direction by conduction. The key to designing the loop is to make it
spread out over a large enough area such that the input of heat from
surrounding earth via conduction is sufficient to overcome the
'withdrawal' of heat by the system.
That would seem to be the case, but in reality what is going on underground
is alot more complex. I'm no geologist, but there's alot of different kinds
of ground, some is more conductive of heat than others. From what I
understand of GSHP, you the tube in the ground and then fill it with a
conductive type of granite rock or something. Don't remember it exactly,
but I do remember that it was made to be very conductive. So it's obvious
that some ground is more conductive than others.
You are not dealing with great delta T's underground, so the heat from the
loop will move slowly thru the rock (which itself is somewhat of an
insulator, or frost lines would be alot deeper. An area of ground heated up
from a ground source heatpump will dissipitate its heat over time. However,
the real question is how long will it take. Having a balance of heating and
cooling will of course help.
Now, rain also drips thru the earth when it rains, its the reason caves
have stalagtites and mites. So you'd have to assume that a good rain would
take some of that heat or cold away by making the ground around the GS Loop
more conductive.
Personally.. Depending on what the ground is like, a GSHP may or may not
work.