Indoor Thermal Comfort Evaluation of an Office Building in the Southern United States

Office buildings are among the most energy-intensive building types, and they frequently present challenges related to indoor air quality and thermal comfort. The actual indoor conditions of such buildings often diverge from design intent for a variety of reasons, including higher-than-anticipated occupancy levels, improper operation of mechanical systems, and reduced internal heat generation. This study examines the gap between measured and desired indoor thermal conditions in a medium-sized office building located in the southeastern United States. Field measurements were conducted in a representative office floor to characterize thermal performance and indoor environmental quality. Three categories of data were collected: indoor climate parameters, outdoor climate conditions, and occupant thermal sensation obtained through a structured questionnaire survey. Analysis of the collected data enabled a comprehensive evaluation of the actual thermal comfort conditions in the study space. Measurement results indicate that the majority of monitored locations fell within the slightly cool range of the thermal comfort zone. Despite this, 88% of occupants reported the thermal conditions as acceptable; however, only 22% expressed a preference for a warmer environment. These findings suggest that occupants have adapted to slightly cool indoor conditions, likely as a behavioral response to the hot and humid outdoor climate characteristic of the region.