Arctic Climate Horizontal Ground-Coupled Heat Pump.

• Main Authors: Belzile, Patrick, Comeau, Félix-Antoine, Raymond, Jasmin, Lamarche, Louis, Carreau, Michel
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: 2017
• Subjects: ground-source heat pump; absorption heat pump; horizontal ground heat exchangers; artic to subarctic climate; subarctic climate; Arctic; Kangiqsualujjuaq; Subarctic
• Online Access: https://espace.inrs.ca/id/eprint/7718/; https://www.geothermal-library.org/index.php?mode=pubs&action=view&record=1033850

Heating buildings in isolated communities of northern Quebec is done by the combustion of fuel oil. Ground-source heat pump is one of the potential technologies to replace oil furnaces but the performance of heat pumps is unknown in arctic to subarctic climate. The ground thermal properties and temperature can have a major impact on the size of the required ground heat exchangers. The simulation of different ground-coupled heat pump systems for a residential size building with horizontal slinky or straight ground heat exchangers located in Kangiqsualujjuaq was therefore achieved to anticipate potential energy savings. Simulations were based on an inventory of geological data available for the area that helped to define the subsurface temperature and thermal properties. Trench length needed for the building having an annual heating energy demand of 15.9 MWh would be between 165 m and 260 m depending on the exact thermal conductivity of the ground. A simulation of the ground heat exchanger operating temperature showed that fluid can reach -13°C, which is lower than the conventional limit of -6.5°C of commercially available heat pumps. No energy savings have been found simulating horizontal ground heat exchangers with a regular heat pump having an electric compressor, even with heat recovery from a diesel engine that would activate the compressor. Simulations performed for an absorption heat pump operated with fuel resulted in viable energy savings. A system with an air-source absorption heat pump offered annual savings of 2 075 $ and 1 482 L of fuel oil, which represents 17.4 % of the fuel consumed by a conventional furnace. Simulations for a ground-source absorption heat pump system indicated savings of 4 702 $ and 3 358 L of fuel oil per year, about 39.4 % of the fuel consumed by a conventional furnace.