Investigating potential HVAC-related energy savings using an occupancy based control system : a study developing and testing an OBC system utilizing occupancy data from thermal imaging

Sammanfattning

Purpose - The purpose of this study was to promote energy savings by reducing or eliminating over-conditioning of indoor air in heating, ventilation, and air conditioning (HVAC) applications by utilizing an occupancy based control system. Methods - This quantitative study was conducted at a global HVAC-organization to ensure real-industry relevance. An experimental research design guided this thesis when establishing a working hypothesis, collecting data, and deriving conclusions. The data collection included a people counting experiment, temperature measurements, and meeting room simulations. Visual and numerical analysis was performed to form conclusions regarding accuracy of a people counting sensor, as well as indoor air quality management and energy savings potential of a proposed occupancy based control system. Findings - When experimentally testing a low resolution thermal people counting sensor, this study concluded an average overall accuracy of 85.8% with aecting factors such as occupancy levels, frequency, and behavior. Furthermore, the proposed system, with sensor implementation, managed to maintain indoor air quality standards. A crucial part for the indoor air quality management of the developed system was the integration of a proportional-integral function. Ultimately, the proposed system created average total air volume savings of 29.3% and average thermal energy savings of 14.5% when compared to a conventional demand controlled venti- lation system. Contributions - This study aimed at investigating the gap in research regarding to which extent an occupancy based control system utilizing a low resolution thermal sensor could enable energy savings. The findings of this study directly targeted this gap, with clear methodological explanaitions, and can therefore bring theoretical contributions. Furthermore, real-world implementation of the findings of this study could enable energy savings, therefore bringing practical contributions.