Closed-loop heat systems pump an anti-freeze solution through ‘loop-pipe’ buried in the ground. The loops can be installed either horizontally in trenches or vertically in a series of boreholes.
The overall length of the pipework required depends on the size of the property to be heated, the thermal properties of the building, the size of the heat pump required and the thermal conductivity of the ground in which the loop pipe is lain. Heat losses between the antifreeze solution and the loop-pipe, the loop-pipe and the grout surround and the grout surround and the ground itself reduces the efficiency of these systems when compared with an open-loop system.
Closed-loop systems, if poorly designed and installed, can result in freezing of the ground thereby reducing the efficiency and life of the heating system. A closed-loop system can, however, be installed anywhere in the country irrespective of the ground conditions.
Closed-loop systems are often cheaper to install than their open-loop counterpart. However, open-loop systems can achieve greater efficiencies and also work well with new build properties and those being converted.