Indoor Environmental Quality in a Mid-Century Research Laboratory Building

Research laboratory buildings are among the most energy-intensive building types due to their high energy demand, ventilation requirements, and the need to maintain controlled indoor environmental conditions. Previous indoor environmental quality (IEQ) investigations exist; however, IEQ research on purpose-built research laboratory buildings, particularly those constructed during the middle of the 20 th century, remains underexplored. This study investigates the IEQ conditions of a mid-century research laboratory building constructed in 1960 and located on the University of Utah campus. Indoor environmental data were collected in two representative chemical engineering laboratories located within the basement and third floors of the building. This paper presents results from a seven-month analysis period, spanning April to October 2025. The monitored IEQ parameters included indoor air temperature, relative humidity (RH), carbon dioxide (CO 2 ) concentration, and fine indoor particulate matter (PM2.5). Measurements were recorded at hourly intervals and analyzed to assess temporal variations at both hourly and monthly scales. The results showed distinct thermal and indoor air quality patterns between the two laboratories. The basement laboratory (Basement Lab) had extended periods of underheating during the fall months, while the third-floor laboratory (Lab 3) exhibited more stable thermal conditions with occasional short-term temperature increases during summer. Relative humidity levels in both spaces showed pronounced seasonal variability, including extended periods below recommended comfort ranges. For both laboratories, CO 2 concentrations generally remained below the commonly adopted indoor air quality threshold of 1000ppm, although intermittent spikes were observed in the third-floor laboratory during occupied periods. Lastly, PM 2.5 concentrations were consistently low in both spaces throughout the monitoring period. Overall, the findings from this study illustrate how IEQ conditions are influenced by floor level, facade exposure, room volume, and occupancy patterns within a mid-century research laboratory building. The study provides empirical evidence that can support future performance assessments aimed at improving occupant comfort and environmental performance in existing laboratory facilities.