Retrofit design and operation strategies for dental clinics with optimised indoor thermal comfort, energy consumption, and life cycle cost

Healthcare buildings have strict thermal comfort requirements and their energy consumption and costs are higher than general public buildings'. In recent years, there has been an influx of research on optimising thermal comfort, energy consumption and cost. However, literature reviews reveal that healthcare buildings have significant differences in thermal environment requirements compared to general public buildings. In addition, medical equipment has a considerable impact on energy consumption and indoor temperatures. Currently, there is a lack of research addressing the unique characteristics of healthcare buildings for this triple-objective optimisation. This study took a dental clinic in Ningbo as the case study, simulated and evaluated the current status of building performance, and proposed the idealised retrofitting strategy based on the results of the sensitivity analysis. Simulation and empirical findings indicated that although the current dental clinic exhibited relatively low energy consumption and life cycle cost (LCC), occupants suffered from significant overheating problems. Adjusting the cooling and heating setpoints to 23.5 °C and 21.5 °C respectively, and replacing the cool reheat dehumidification control HVAC system, although resulting in a slight increase in annual energy demand (AED) and LCC, dramatically improved the thermal comfort indicator AaPMV2¯ from the original 0.625 to 0.402. And this is the idealised solution yielded by the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) method, with surveyed weights of AaPMV2¯, AED and LCC of 0.5, 0.255 and 0.245 respectively. The research outcomes can serve as references for treatment space retrofit programmes. The novelty of this research lies in proposing a comprehensive analysis of retrofit strategies for treatment space considering thermal comfort, energy consumption, and cost, with the application of the adaptive thermal comfort model and the consideration of medical equipment's energy useage and heat production.