A friend is in construction of his house right now, and plans to install a
home-grown geothermal heating system in the driveway to keep snow off. I'm
not convinced it will work, but since we're planning to build next year, if
it does work, it sounds very cool, and I'm going to want to do it too :)
Basically, he's planning on putting down pex (I think ?) tubing before the
asphalt is laid down, so it's embedded in the asphalt. That will lead to
several loops dug down below the frost line for heat transfer.
Hrm - not sure if he's going vertical or wide horizontal loops. It's a
closed loop system, with a small pump to move the glycol solution through.
He hasn't done any calculations at all, just "it should work" :) It sounds
like it will, but I don't know how to calculate if it will or not.
I thought of using a manifold system, with two main pipes along the sides
of the driveway and ladder-like rungs of pipe between them. Each run would
have several loops, to ensure sufficient time for heat transfer.
He's against that - worried about the T-joints leaking. He wants to run
one or two looong loops. I'm thinking that at the end of the loop, all the
heat will have already been removed from the fluid, and it won't be
effective. So you would get one end nice and clear of snow, the other end
as if the system was off.
So, questions are ... Is this even feasible ? Would there be enough heat
transferred to keep the driveway above freezing point ? I would think so,
sort of, since below-ground is a fairly static 50degF or so, isn't it ?
And what would the best layout be ? Long loop, or manifolds ?
Anything else ?