Waterless Heat Pump Systems | DX Systems
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 water-source.
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.
Waterless -Direct Expansion
Heat Pump Systems
DX (Direct Expansion) systems are
a third style of heat pump system.
The main difference between a
direct expansion system and
water based systems (open or
closed loop) is the medium used
to transfer heat.
Rather than water, a DX system
extracts heat from the ground via
buried copper tubing containing