Heating Circulation Pumps
Heating circulation pumps are used to circulate gases and liquids in closed circuits. Grundfos, DAB, Halm and other major brands of circulation pumps are used commonly to circulate hot water around domestic or commercial hot water systems, especially in the following two types of geothermal energy applications.
Open source heat circulation pumps use water from a borehole or watercourse and extract heat from it for domestic hot water heating. The water is then returned to another borehole or water course. The heat pump has a heat exchanger that transfers the water's heat to the distribution system. A borehole-based system using groundwater is efficient for domestic heating as the groundwater remains at a constant temperature all year round. This means that the heat can be used throughout the year, including winter. Larger properties need higher capacity heat pump. Usually, the pump supplies 1 kW of power for each 2 litres per minute of water flow.
Closed ground source heat circulation pumps extract heat from the ground using buried pipe work. The heat is transferred via a heat exchanger in the pump to the domestic water or heating / cooling system. The pump circulates a refrigerant-like mixture of water and antifreeze in a group loop, in the buried pipe work. In temperate climates the subsurface ground temperature remains at a constant level year round so that the pump can be used on a 12-month basis.
High efficiency geothermal heating circulation pumps such as the Halm KGPA series pumps are available in sizes of 1 ¼ inch and I ½ inch x 180 mm. The three-stage pressure heads range between 7 and 12 metres and are able to deliver up to 12 cubic metres per hour of water.