I'm fairly familiar with the principle of ground source heating but not too much of the detail. On last night's Grand Designs the building sat on 46 10-metre deep concrete piles, and wired to the reinforcing cage were loops of the heat pump pipework. (See http://www.channel4.com/4homes/ontv/grand-designs/houses/M/maidstone-bungalow-gallery_image3.html and http://www.channel4.com/4homes/ontv/grand-designs/houses/M/maidstone-bungalow-gallery_image4.html) This adds up to just about 1 km of pipework, not in one giant loop but attached via manifolds.
As the pipes are embedded well into the concrete, will they pick up enough heat from the ground? And at 1 km, won't this need some hefty pump to circulate the fluid around the pipes, and thus negate some of the energy gain?
There was also a ground air heating system, where a large dia pipe was set 1.5 mtr underground and air pumped through it, but I can't find any details of that.
I'm not criticising the program (although most of the grand designs I end up hating), I'm just curious about the techniques. the house isn't finished so there's no final test wether it works or not.
As the pipes are embedded well into the concrete, will they pick up enough heat from the ground? And at 1 km, won't this need some hefty pump to circulate the fluid around the pipes, and thus negate some of the energy gain?
There was also a ground air heating system, where a large dia pipe was set 1.5 mtr underground and air pumped through it, but I can't find any details of that.
I'm not criticising the program (although most of the grand designs I end up hating), I'm just curious about the techniques. the house isn't finished so there's no final test wether it works or not.