Abstract
Geo-exchange systems allow heat pumps to be operable in colder regions where the low efficiency of conventional heat pumps prohibit their usage. The barriers to the widespread usage of the geo-exchange systems are as following: 1) the high costs associated with the installation of the deep-well heat exchangers and horizontal-trench heat exchangers, 2) the high cost of real-estate in urban/suburban areas supporting the required footprint. The aims of this project (phases I-III) is to increase the energy density of geo-exchange (heat) systems resulting in reduced installation costs and land requirements. Theoretically, by burying a fluid (water) filled tank, hosting the outdoor heat-exchanger, in the ground and below the frost line, a stable temperature could be achieved. This provides an optimal location for year-round heat transfer from the surrounding ground to the water within the tank and from the water to the heat-exchanger. The project focused on the proper instrumentation of the system (using electronic sensors, a mini-computer, and the required coding/programming) as well as the ground-heat source (simulation) and aimed to build upon the phases I & II. The instrumentation of the system was achieved using appropriate electronics. The installation of the heat belt and the insulation of the tank had no effect on the COP of the heat pump and/or the heat transfer rate as made possible to be evaluated by the instrumentation and the data analysis. However, the installation of the heat belt and the insulation of the tank increased the system lockout time by ~ 14 hours.