Applications
Because of their small earth loop size, DX systems can be installed in relatively small areas and in relatively shallow soil. This provides a flexibility of installation that is useful in allowing many properties to be served by geothermal that could not be served otherwise. A direct exchange system ground loop can be drilled with a small drill rig that can fit into small side yards and gardens under existing trees. It can be drilled in areas where rock is found 50 foot (15 m) to 100 foot (30 m) below ground without the need for actually drilling into rock.
Because DX derives its efficiency from the direct heat exchange between refrigerant and ground, the compressor unit cannot be placed at great distance from the earth loops. This can limit some DX applications. However, the use of multiple distributed compressor units on a single project can allow DX systems to serve large buildings.
Read more about this topic: Direct Exchange Geothermal Heat Pump