To investigate age-related differences in preferred air speed in warm conditions, experiments were conducted in a climate-controlled chamber. 24 young and 24 elderly participants were tested in windless and preferred wind conditions. A resting metabolic rate (RMR) prediction model based on body composition was proposed to examine the effects of individual differences on preferred air speed. Results showed that the elderly exhibited lower RMR than the young, but their mean preferred air speed was 1.3 m/s, significantly higher than that of the young (0.9 m/s), corresponding to their higher mean skin temperatures. Preferred airflow effectively reduced thermal sensation and perceived sweating, thereby improving thermal comfort and airflow acceptance. During airflow exposure, mean skin temperature decreased, while LF/HF index of heart rate variability and skin conductance level increased, indicating enhanced sympathetic activity. These findings suggest that reduced sweat gland function and evaporative heat dissipation cause the elderly to require higher air speeds to achieve thermal neutrality. Their reduced thermal sensitivity further highlights the need for more precise environmental control. RMR exerted a more pronounced influence on the preferred air speed among the elderly, underscoring its significance in designing thermally adaptive environments for aging populations.
Wang et al. (Wed,) studied this question.