Systems with horizontal collectors

Heat pump systems with horizontal collectors

A pipeline system filled with liquid is put into 1.5-2-meter deep trenches. Heat energy of the soil warms up the liquid that flows with a calculated flow rate in the pipes. This heat gain can be extracted from the liquid by the heat pump to transform it to a higher temperature. The horizontal systems are designed to extract heat from the upper 3-4 meters of the soil that is heated by the sun radiation. The energy flow from the center of the Earth plays a little role only.

Adventages:

• installation costs are generally less expensive than thos of the vertical boreholes,
• they are closed systems, so thre is no need to install serious filters as in case of water wells or other open systems,
• they can operate with acceptable efficiency in spring and autumn.

Disadventages:

• they need big lands for digging (appr. 2.5-3 times more than the whole floor surface of the house to be heated),
• the extracted amount of heat energy has very big influence on the temperature of the upper layers of the soil,
• when the heat request is the biggest in winter, the temperature of the upper 1.5-2 meters of the soil is the lowest. So the efficiency falls down,
• trees and bushes cannot be planted above the pipeline system otherwise their rots can cause damages.