Essentials Of Geosource Heat PumpsIn winter, the Earth's temperature at about four feet below ground level is more than that of the ambient air circulating homes and buildings. This fact is utilized by geosource heat pumps to help transfer the heat from the Earth to the cold air circulating homes. In the process they help heat homes with substantial energy cost savings. Geosource heat pumps are simply 'refrigeration units' driven by electrically powered compressors. The only distinguishing feature is that the former devices heat homes in winter, whereas the latter devices cool the refrigerator space. Another difference between the two is that heat pumps work too as home-cooling devices during summers. Geosource heat pumps work with a shorter temperature difference than do air-source heat pumps such as air conditioners. The two bodies the temperature difference refers to are the Earth and the air circulating homes in the case of geosource heat pumps and the air inside and outside homes for air-source heat pumps. The larger the temperature difference, the larger is the electrical energy that is consumed by the compressors driving the respective heat pumps. More energy consumption means lower efficiency. This is primarily why a geosource heat pump is much more energy efficient than an air source heat pump. Geosource heat pumps are complete packages by themselves and form the core of geo thermo heating systems. Each package comprises a refrigerant to water heat exchanger, an electrically driven compressor, refrigerant piping and control valve, fan and its controls, and an air coil. This last item cools and dehumidifies the air in summer and heats it in winter. The single-package design has the advantage that much less refrigerant is needed to achieve the heating. This is in contrast to air-source heat pumps in which comparatively more refrigerant is used due to the 'split design used therein. Another advantage that the geosource heat pump enjoys is the low potential for refrigerant leakage. This results in a more reliable heating system. There is no scope of environmental damage because of leakage of the R-22 transition refrigerant used in almost all geosource heat pumps. This is because the refrigerant has a comparative very low ozone depletion value of 0.05. This is based on the maximum damage potential achieved by R-11 and R-12 refrigerants. High efficiency heat pump equipment from some reputed geothermo companies come with high efficiency compressors, larger air coils, and in some cases larger refrigerant to water heat exchangers. Those from geothermal climate system manufacturers boast of multi-speed dual compressors, water to water heat pumps, and split systems. Naturally, geothermal prices are comparatively higher in the latter case. The heating performance of geosource heat pumps is based on their COP (coefficient of performance) rating. It is the ratio of the heating effect produced to the electrical energy consumed (both in the same energy units) to produce that effect. |