Water circulating through this loop takes the heat from the building and transfers it to the ground by conduction. A normal AC transfers the building heat to the air at the outside fan unit. Since the ground is always a lot cooler than the air, the GSHP system is much more energy efficient than conventional units. The operating temperature is so low, in fact, that the compressor hardly ever has any mechanical problems. The opposite process takes place in the winter.
Heat is extracted from the ground, and transferred to the building via the water loop.
The ground temperature increases in the well field during the summer cooling months, and this is the heat that is extracted in the winter for space heating. At the end of the winter the ground is much colder than usual, so there is a really cold source for the summer time. The initial installation does not have to cost much more than other systems. The Austin ISD uses the ground loops because there is such a big problem of vandalizing, and all the GSHP equipment is safely buried under ground out of harm s way. Water source systems are not limited to schools or buildings with a large land area available for the well field.