Experimental and Numerical Study of Ground-Source Heat Pumps
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Date Issued
May 2026
Author(s)
Cyprus University of Technology
Advisor
Abstract
Ground Source Heat Pump (GSHP) systems have emerged as a highly efficient and
environmentally sustainable technology for heating and cooling applications in
residential, commercial, and public buildings. Their growing adoption is driven by their
capacity to significantly reduce energy consumption and greenhouse gas emissions while
utilizing shallow geothermal energy as a renewable resource. Nevertheless, challenges
associated with high initial investment costs, system optimization, and climatic adaptation
continue to limit their wider implementation, particularly in Mediterranean regions. This
thesis investigates the performance, design, cost-effectiveness, and dynamic behavior of
GSHP systems operating under Mediterranean climatic conditions, with a particular focus
on Cyprus. The research combines an extensive literature review with experimental
investigation, economic evaluation, and advanced dynamic simulation of a large-scale
geothermal installation located in the historic Municipal Library of Limassol, Cyprus.
The study examines multiple ground heat exchanger (GHE) configurations integrated into
a single GSHP system, including vertical borehole heat exchangers, double helicoidal
coils installed in wells, and open-loop groundwater systems. Continuous operational
monitoring through a Building Management System (BMS) enabled the collection of
high-resolution data related to thermal loads, flow rates, inlet and outlet temperatures,
energy transfer, and heat pump performance in both heating and cooling modes. The
experimental analysis demonstrates that GSHP systems operating in Mediterranean
climates can achieve high seasonal efficiencies, with seasonal coefficients of performance
(SCOP) ranging between 4.5 and 5.0. Results further indicate that open-loop groundwater
heat exchangers provide the highest thermal exchange rates and the lowest installation
cost per unit of delivered energy when groundwater availability permits. Comparative
economic analysis revealed significant differences in cost-effectiveness among the
investigated GHE configurations, highlighting the importance of site-specific geological
and hydrogeological conditions in system selection and design. To further investigate
system behavior, a physics-based dynamic simulation model was developed in the
Modelica environment using the Buildings library and validated against measured
operational data. The model successfully reproduced both transient and steady-state
thermal responses of the GSHP system, including borehole heat exchange processes, heat
pump operation, and building thermal interactions. Good agreement between measured and simulated results confirmed the reliability of Modelica-based approaches for
predicting GSHP performance under real operating conditions. Overall, this thesis
contributes to the understanding of geothermal heat pump technologies in Mediterranean
environments by integrating technical, economic, and simulation-based analyses into a
unified framework. The findings demonstrate that properly designed and optimized
GSHP systems can provide substantial energy savings, reduced environmental impact,
and long-term economic benefits. Furthermore, the work offers practical guidance for the
design, operation, and optimization of geothermal systems in historic and modern
buildings, supporting the broader deployment of renewable energy technologies in the
built environment.
environmentally sustainable technology for heating and cooling applications in
residential, commercial, and public buildings. Their growing adoption is driven by their
capacity to significantly reduce energy consumption and greenhouse gas emissions while
utilizing shallow geothermal energy as a renewable resource. Nevertheless, challenges
associated with high initial investment costs, system optimization, and climatic adaptation
continue to limit their wider implementation, particularly in Mediterranean regions. This
thesis investigates the performance, design, cost-effectiveness, and dynamic behavior of
GSHP systems operating under Mediterranean climatic conditions, with a particular focus
on Cyprus. The research combines an extensive literature review with experimental
investigation, economic evaluation, and advanced dynamic simulation of a large-scale
geothermal installation located in the historic Municipal Library of Limassol, Cyprus.
The study examines multiple ground heat exchanger (GHE) configurations integrated into
a single GSHP system, including vertical borehole heat exchangers, double helicoidal
coils installed in wells, and open-loop groundwater systems. Continuous operational
monitoring through a Building Management System (BMS) enabled the collection of
high-resolution data related to thermal loads, flow rates, inlet and outlet temperatures,
energy transfer, and heat pump performance in both heating and cooling modes. The
experimental analysis demonstrates that GSHP systems operating in Mediterranean
climates can achieve high seasonal efficiencies, with seasonal coefficients of performance
(SCOP) ranging between 4.5 and 5.0. Results further indicate that open-loop groundwater
heat exchangers provide the highest thermal exchange rates and the lowest installation
cost per unit of delivered energy when groundwater availability permits. Comparative
economic analysis revealed significant differences in cost-effectiveness among the
investigated GHE configurations, highlighting the importance of site-specific geological
and hydrogeological conditions in system selection and design. To further investigate
system behavior, a physics-based dynamic simulation model was developed in the
Modelica environment using the Buildings library and validated against measured
operational data. The model successfully reproduced both transient and steady-state
thermal responses of the GSHP system, including borehole heat exchange processes, heat
pump operation, and building thermal interactions. Good agreement between measured and simulated results confirmed the reliability of Modelica-based approaches for
predicting GSHP performance under real operating conditions. Overall, this thesis
contributes to the understanding of geothermal heat pump technologies in Mediterranean
environments by integrating technical, economic, and simulation-based analyses into a
unified framework. The findings demonstrate that properly designed and optimized
GSHP systems can provide substantial energy savings, reduced environmental impact,
and long-term economic benefits. Furthermore, the work offers practical guidance for the
design, operation, and optimization of geothermal systems in historic and modern
buildings, supporting the broader deployment of renewable energy technologies in the
built environment.
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