Towards whom should indoor environmental quality control be sympathetic – Asthmatics or non-asthmatics?

• Asthmatics have higher nasal thermal perception at cooler thermal comfort conditions.
• Non-asthmatics have higher perception of ozone-initiated pollution at realistic levels.
• Temperature settings should be sympathetic towards asthmatic subjects.
• IAQ settings should be sympathetic towards non-asthmatic subjects.

From two independent research studies conducted to understand effect of varying thermal and indoor air pollution exposures on non-asthmatics and asthmatics' responses and work performances, this paper attempts to answer the question: Towards whom should IEQ control be sympathetic – asthmatics or non-asthmatics? The studies were conducted in a 240 m3 field environment chamber at the National University of Singapore. Subjects, between 20 and 30 years of age, were recruited from the university community to participate in these studies. In the first study, the interventions were two room air temperatures, i.e. 21.2 ± 0.3 °C and 25.0 ± 0.2 °C at constant ventilation. This study lasted for 8 h. Data were collected for inhaled air thermal sensations and salivary α-amylase concentration before and after 8-h exposures. In the second study, subjects were exposed to limonene and ozone (of simulated outdoor origin) at realistic concentrations for 3 h. Data for subjects' work performances, perceptual responses, and salivary α-amylase concentration at initial and after 3-h exposures were reported in this paper. The main findings suggest that: (i) temperature settings should be sympathetic towards asthmatic subjects because of their higher sensitivity to temperatures at the lower spectrum of thermal comfort conditions; (ii) IAQ settings should be sympathetic towards non-asthmatic subjects because of their higher sensitivity to perceived air quality acceptability in the same temperature range. Knowledge gained from this paper has practical implications towards creation of environmentally friendly indoor environment for asthmatic and non-asthmatic building occupants.