A geothermal heat pump aims to harness heat from the ground to make homes comfortable and habitable throughout the year. Heat pumps usually work by moving heat from one source to another; and the geothermal unit, in this case, transfers heat between the ground and the enclosed home interiors on the surface.
Layout and Working
The structure and working of a geothermal heat pump is very much similar to that of a refrigerator, comprising a compressor, blower, condenser and a series of looped tubes. The tubes contain a permitted, safe refrigerant and/or water, which imbibe and distribute the heat. Loop configurations in a geothermal unit are laid out below the surface of the ground, and vary based on the terrain, soil conditions, climate and temperature settings, heating and cooling needs of the home, and the expanse of the home.
Loop structure usually comprises polypropylene tubes or copper tubes through which water or other safe anti-freeze solutions are circulated to transmit heat to and from the ground.
Types of Loop Configurations
There are two common loop configurations, where loops are laid horizontally or vertically beneath the earth in a closed setting.
• Horizontal configurations typically occupy more space, needing about 400 – 600 feet of space for every ton of cooling and heating. Loops are laid three to six feet beneath the surface.
• Vertical loops work well, both with rugged terrain and limited spaces. Deep holes anywhere between 150 and 400 feet are drilled, and one u-shaped tube inserted in each of them. The top of these vertical tubes are then connected to a horizontal tube that carries the heat exchanging fluid.
Costs Involved In Installing A Geothermal Heat Pump
A geothermal unit is expensive when compared to other heat exchange systems, with all costs being payable upfront. Costs vary based on the heating and cooling needs, the length of the loop, and the configuration. Horizontal loops incur more costs, as they stay relatively close to the surface and require an elaborate configuration to lap up the heat. Vertical loops, on the other hand, penetrate deep into the earth’s surface, in order to tap a sustainable heat source.
These ultra-high efficiency geothermal units have relatively low operational and maintenance costs, easily saving at least 20 % of home heating and cooling expenses. Underground loop configurations are expected to last at least 50 years; the infrastructure within the homes should stay good for at least 25 years. Fitted with additional desuperheaters, heat from a geothermal unit can also be used to heat water for home needs.