Quantifying human thermal adaptation for indoor environments through field surveys and climate chamber experiments: Fid-Bau Portal

Quantifying human thermal adaptation for indoor environments through field surveys and climate chamber experiments

Upadhyay, Krishan / Elangovan, Rajasekar / Subudhi, Sudhakar

Thermal comfort boundaries established through climate chamber experiments are often found to significantly vary in real-world conditions based on the potential for thermal adaptation. In this context, this research aims to quantify the extent of thermal adaptation using a personalized ventilation system. We hypothesize that a personalized ventilation system can enhance thermal adaptation compared to real-world settings with limited opportunity for thermal adaptation. The study is based on thermal comfort surveys in mixed-mode open-plan office spaces of a humid subtropical region (Cwa), and a controlled climate chamber with a provision for personalized ventilation. We obtained 5629 subjective thermal responses through longitudinal field surveys accompanied by environmental measurements. In a climate chamber, 16 acclimatized volunteers were subjected to 140 different set-points with air temperature (T_a), relative humidity (RH), and air velocity (V_a) variations yielding 19,200 subjective responses. A thermo-neutral temperature (T_n) of 26.5°C with an acceptability band of ±5.9°C was obtained through the field surveys. The T_n obtained from climate chamber surveys varied from 28.0°C to 29.3°C with an acceptability band of ±3.6°C depending on the ventilation rate. An empirical relationship between thermal sensation vote (TSV) and multiple environmental variables (Calidity) suggests 2°C higher T_n for Calidity_chamber, Thermal adaptation correction factor of 2.1°C for warm-dry indoor environment and 1°C for warm-humid indoor environment were deduced through comparative analysis.