Abstract

Geothermal heat exchanger technology is the most efficient method of heating, cooling, or refrigerating any enclosure that can be conditioned. The earth’s thermal mass has an almost-endless capacity to absorb and store heat. Geothermal heat pumps (GHPs) first became well known in the energy crises of the 1970s in the United States; they had been used in Europe for many years before that. Since then, this technology had been researched and implemented successfully in projects of all sizes—from small mobile homes to large schools and universities and to complete developments with multiple systems. These systems can refrigerate down to below 0°F and heat water for domestic use up to 120°F. Geothermal systems have been applied successfully to projects around the world, from inside the Arctic Circle to the desert regions. Geothermal systems have been applied to projects from large buildings in the country to medium-size structures in Manhattan. The larger the demand placed on a heating, ventilation, air conditioning, and refrigeration (HVAC/R) system, the faster the payback period for the upfront capital cost. Vertical GHP systems can usually be built for about the same cost as a four-pipe chiller/boiler system. Geothermal technologies are considered to be renewable energy as well as energy-efficient technologies. These systems should never be overlooked when thinking about designing any system for the purpose of conditioning space or the temperature of a material or process. These systems are not complicated and can be among the simplest systems for the purposes to which they are applied. This entry explains some of the basic concepts and terms used in this industry.