@phdthesis{oai:air.repo.nii.ac.jp:00005802,
 author = {DACQUAY, CONNOR MITCHELL},
 month = {Sep},
 note = {This research presents the outcomes from two main objectives with the first being the creation of a novel design of integrating electrochromic glass window controls with a GSHP system for long-term op-timization and sustainability. For the first objective, a building energy model was developed and simu-lated with the solar heat gain coefficients of 0.41, 0.25, 0.15, and 0.09 to model electrochromic glass windows. The energy model outputs were used for ground heat exchanger model simulations which ana-lyzed 20-year temperature trends and system efficiencies. The results showed that the integrated GSHP system with electrochromic windows was feasible and a conceptual control sequence and design was developed. The annual cooling demand decreased by 32% between the clear glass and fully tinted state. It was recommended to increase the ground heat exchanger capacity to 200 boreholes at 45.7 m in 2040 to prevent overheating from projected climate change. The average system coefficient of performance was 7.6 for the fully tinted window state. The integrated GSHP system reduced CO2 emissions by 30% and the 30-year NPV was US$142,273.65 (-26%) cheaper compared to a conventional boiler and chiller system.
The second objective comprised of the development of a novel software and hardware package that dynamically predicts future ground heat exchanger temperatures to avoid thermal imbalance and future ground source heat pump system failure. An energy meter was installed on the ground heat exchanger of an office building and a software was created on a remote server that collected the measured data. The future ground temperature was dynamically calculated, and the prototype was integrated with the build-ing automation system to prevent future ground source heat pump system failure. The results showed that the building was cooling dominate and if the current mechanical system operation continued, the system would become inefficient in 16 years from high inlet temperatures to the heat pumps. A control sequence was developed for mitigating ground heat exchanger failure on the studied building. It was also determined by adjusting the set-point temperature of the make-up air unit from 12.8C to 4.8C, the amount of heating performed by the ground source heat pump system would increase from 81,122 kWh to 120,453 kWh which maintained the calculated 20-year ground heat exchanger temperature below 32C. The prototype developed in this paper is critical for maintaining an efficient ground source heat pump system and adequate ground heat exchanger temperatures. The outcome of the second objective provides the solution of ensuring a successful adoption of sustainable green technology on a large scale and eliminates ground source heat pump system failure due to thermal imbalance.},
 school = {秋田大学},
 title = {Ground heat exchanger thermal imbalance prevention; feasibility, development, and implementation},
 year = {2022}
}