Source: http://www.listfree.org/38824-geothermal-systems-heating-from-the-ground-up.html The demand on maintenance and engineering managers to provide comfortable temperatures and good indoor air quality while keeping a tight grip on the budget is among their greatest challenges. On top of the energy costs, there is a maintenance cost for HVAC, boilers, chillers and cooling towers, which can stretch staff skills and time in many directions. Yet there is a way to provide a high level of comfort without taxing the budget or the staff. The geothermal heat pump systems can cut maintenance and energy costs in half. How Geothermal Heat Pump Works Geothermal heat pump systems rely on the temperature of the earth to heat and cool buildings. While there is a variety of designs, the most popular design relies on heat pumps and a closed-loop system of pipes laid under the ground or a body of water. The efficiency and simplicity of the system is due to the closed-loop system that acts as a large heat exchanger. The loop is filled with a heat-transfer fluid, typically water or a water-antifreeze mix. When a facility requires cooling, heat is transferred from a building to the earth. When heating a facility, heat is absorbed from the earth and transferred to the building. The system utilizes a heat pump that uses a refrigerant cycle to take low quality heat and concentrate it to high quality heat. Pumps and fans then move the heat. The system is efficient and simple because it moves heat and does not create heat. In addition, while most mechanical cooling systems work under the same principles, geothermal systems gain efficiency because of the size of their primary heat exchanger — the loop. At the heart of the process are two thermodynamic principles: Heat always flows from hot to cold, and the greater the difference in temperatures, the higher the rate of heat transfer. Six to eight feet beneath the surface of the earth, the ground maintains a constant annual temperature from 45 in the north latitudes to 70 degrees in the south. Because the earth’s temperature is stable and the ambient air temperature is not, there is a seasonal differential in most climates that makes the geo-thermal process efficient. Cost Savings The relative simplicity of the systems is in part what makes them cost effective. Geothermal heat pump systems do not rely on boilers and cooling towers. Since reversing-cycle technology is deployed at the point of use, there are only two pipes to provide heating and cooling, not four like most conventional systems. And there are no large chillers in the mechanical room or an array of packaged units on the roof exposed to the elements and creating potential problems for the roofing system. All the critical equipment, except the ground loop — pumps, scroll compressors and fans — are inside the building, protected from the elements. The heat pumps are generally small, which makes them more flexible in terms of design. While so