Geoexchange is the often overlooked renewable energy source that sits below your building. It also makes for a perfect match with radiant systems.
Geoexchange
Key benefits
Energy efficiency
Geoexchange systems provide three to four units of electrical energy for every one unit used to power the system. In cooling mode, geoexchange systems can be two- to three-times more efficient than traditional air conditioners or air-to-air heat pumps. This improved efficiency translates directly to reduced operating costs.
Architectural freedom
The heat exchanger is underground, so it doesn't take up any usable space in your building. The heat pump is similar sized to a boiler or furnace, but does not need to be vented outside, as a gas boiler would. You also don't need to run a gas line to the appliance.
Electrification friendly
Geoexchange heat pumps do not burn fossil fuel. By utilizing the consistent temperature of the loop field, modern heat pumps use 66-75% less energy than electric resistance heating/cooling appliances.
Low maintenance
The buried ground loops of RAUGEO are protected from the elements and damage. You don't have an outdoor unit to protect and clean, like traditional air-conditioning. Furnaces and boilers require additional, yearly maintenance to ensure proper combustion and operation, also.
How it works
Unlike outdoor temperatures that fluctuate with the changing seasons, the temperature of the earth four to six feet beneath the ground remains relatively consistent year-round for a given location. A geoexchange system, sometimes called geothermal, takes advantage of this consistent temperature as a low-temperature heat exchanger and connects to an electric heat pump.
According the International Ground Source Heat Pump Association, "during the winter, the fluid collects heat from the earth and carries it through the system and into the building. During the summer, the system reverses itself to cool the building by pulling heat from the building, carrying it through the system and placing it in the ground."
A circulator in your building distributes the water through a network of PEX to radiant panels or hydronic fan coils.
Components of the RAUGEO system:
- RAUGEO U-bend vertical ground loop
- RAUGEO Collect horizontal ground loop
- Balancing manifold
- Geothermal heat pump
- Radiant heating and cooling distribution piping system
Contact a REHAU expert to talk about a geo project
Request a sample design
Installation
RAUGEO U-bend Vertical Ground Loop
Where space is limited and energy demand is significant, such as in most commercial applications, vertical ground loops are inserted in boreholes which are several hundred feet deep using a well-drilling rig. The RAUGEO double U-bend design requires up to 30% less borehole footage than a single HDPE U-bend.
RAUGEO Collect Horizontal Ground Loop
Where there is plenty of open space and suitable soil conditions, ground loops can be installed in long horizontal trenches about 5 to 7 ft (1.5 to 2 m) below ground. This method requires more available land than vertical boreholes and can cause a disturbance to lawns and landscaping, but is the most economical option from an installation cost standpoint.