Waterless Heat Pump Systems | DX Systems
Rather than water, a DX system extracts heat from the ground via buried
copper tubing containing refrigerant.
Using a refrigerant eliminates the need for a heat exchanger between the
refrigerant loop and the water loop, as well as eliminating the water pump.
These simpler systems are able to reach higher efficiencies while also
requiring a shorter and smaller pipe to be placed in the ground, thus being
less expensive to install. DX systems are a relatively newer technology than
The DX loop system can normally be installed in a horizontal area about 40%
smaller than a conventional plastic ground loop. Normal loop length is only
350 ft. per ton.
Vertical systems can be installed in a 3" diameter vertical bore and require
100 ft. of copper "U" tube per ton.
The DX system does not require loop pumps or loop fluid since the
refrigerant absorbs heat directly from the ground.
DX systems are very efficient and often are the system of choice where land
area is at a minimum. As with the open and closed loop systems, DX
systems are available with water or air output.
Expansion Heat Pump
DX (Direct Expansion)
systems are a third style of
heat pump system.
The main difference between a
direct expansion system and
the water based system (open
or closed loop) is the medium
used to transfer heat.