Assessment of suitable locations for a ground source heat pump (GSHP) system based on the groundwater condition of study area is important for its sustainable development. Installation potential of a GSHP system was evaluated for the Aizu Basin, Japan. Firstly, suitability assessment was done for a conventional closed-loop system by preparing a distribution map of heat exchange rates for space heating. Heat exchange rates were higher at the northern and southern areas and lower at the central area, indicating that the northern and southern areas are appropriate for the conventional system. A different type of GSHP system using an artesian well was proposed at the central area because groundwater is flowing in an upward direction and using its heat energy can increase heat exchange rates. Demonstration of this system using an artesian well for space heating resulted in higher heat exchange rates compared to the conventional system. A GSHP system using an artesian well is suitable at the central area, and the conventional one is suitable at the northern and southern areas. Assessment of the installation potential of different types of GSHP system in the same Aizu Basin based on its groundwater condition is unique to this study. It can assist in selecting suitable locations for GSHP system installation and to promote its growth in Japan.

Evaluating the installation potential of ground source heat pump (GSHP) systems based on the hydrogeological condition of an area is important for the installation and sustainable use of the system. This work is the first to have compared the distributions of heat exchange rate in the Sendai Plain and Aizu Basin (Japan) in terms of topographical and hydrogeological conditions. A regional groundwater flow and heat transport model was constructed for the Sendai Plain. Suitability assessment was conducted for an identical closed-loop system by preparing the distribution maps of heat exchange rate for space heating for the plain and basin. For both locations, the upstream area showed a higher heat exchange rate than the downstream area. Multiple regression analysis was conducted using heat exchange rate as a response variable. Average groundwater flow velocity and average subsurface temperature were considered as explanatory variables. The heat exchange rate for the plain, whose Péclet number ranged from 3.5 × 10−3–7.3 × 10−2, was affected by groundwater flow velocity and subsurface temperature. The exchange rate for the basin, whose Péclet number ranged from 8.5 × 10−2–5.8 × 10−1, was affected by groundwater flow velocity. Inland basins are likely to be more suitable for GSHP system installation utilizing groundwater flow than coastal plains in terms of inclination of slope. This study showed that multiple regression analysis can reveal factors affecting the heat exchange rate as well as the degree to which they affect it.

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