Thermal Response Test for BTES Applications-State of the Art 2001

The thermal conductivity of the ground and thermal resistance of the borehole heat exchanger (BHE) are important design parameters for BTES systems and may be determined from in situ measurements, giving reliable design data. Such tests are usually economically feasible when designing BTES systems comprising more than a few boreholes. The measurement method has rapidly developed in the last decade and is now usually referred to as Thermal Response Test. Since the initial mobile test rigs were built in 1995 in Sweden and USA, this technology has been utilized in a number of countries. This paper refers to the state-of-the-art report resulting from work done within IEA ECES Annex 13, Subtask A2 “Thermal Response Test for UTES Applications”. A summary of thermal response testing activities and the current status of the equipment, analysis methods, and test experiences of thermal response testing until December 2001 is presented.