Dandelion accomplished a "few dozen" techniques last 12 months.

A couple of toes beneath the surface, the soil 
sits at a dependable 50- to 60-degree Fahrenheit all 12 months round.
In response to Hannun, the custom equipment has a vibrating head that causes the soil 
to act more like a liquid. X prototyped a number of bold options including a high-pressure water jet, a modified jackhammer that might worm 
its manner underground and the usage of liquid nitrogen to 
create frozen and simply chippable soil. On its website, Dandelion claims 
that a $36,725 system will run you $18,433 instead.
The latter is unusual and extremely attractive because it permits cash-strapped homeowners 
to install a system and begin saving on their utility payments right away.
Most companies will ship an engineer to assess your own home and design a 
bespoke or highly custom-made system. A large indoor 
heat pump makes use of the mixture to boil a refrigerant fluid; the ensuing fuel is then compressed to larger temperatures and distributed round the home.