Quantifying the nationwide HVAC energy savings in large hotels: the role of occupant-centric controls

This paper presents a nationwide simulation study to investigate the HVAC energy savings potential of occupancy sensors and occupant-centric controls (OCCs) in large hotel buildings. Three simulation scenarios were defined to reflect the different levels of occupancy sensing capabilities. Multiple zone-level and system-level occupant-centric HVAC control strategies were extracted from the updated ASHRAE Standard 90.1 - 2016 and 90.1 - 2019 to facilitate the control purpose. 19 climate zones defined in the International Energy Conservation Code and two versions of ASHRAE Standard 90.1 were considered to include the diversities of climates and building vintage. The simulation results showed that the HVAC energy savings ratios varied from 24% to 58% depending on the sensor type, local climate zone, and version of building energy code. It was also found that the occupant counting sensor could achieve an additional 5%-15% HVAC energy savings for the whole building compared with the presence sensors.