Human behavior in different TDRAs.

Area of Science:

• Environmental Science
• Human Physiology
• Building Science

Background:

• Operative temperature integrates radiant and air temperatures, crucial for thermal comfort assessment.
• Understanding human physiological responses to varying temperature differences is essential for optimizing indoor environments.

Purpose of the Study:

• To investigate human physiological and comfort responses to different temperature differences between radiant and air temperature (TDRA).
• To analyze how varying TDRA impacts skin temperature, thermal sensation, and comfort votes.

Main Methods:

• Controlled experiments with four TDRA levels (0, 5, 8, 10°C) at two operative temperatures (28°C and 32°C).
• Recorded measurements included mean skin temperature (MST), local skin temperature (LST), thermal sensation vote (TSV), and thermal comfort vote (TCV).

Main Results:

• At TDRA of 0-5°C, MST remained stable, with minor LST changes (face, upper arm).
• Above 5°C TDRA, MST and LST decreased as TDRA increased.
• Thermal sensation shifted from warm to cool with increasing TDRA from 0 to 10°C.

Conclusions:

• The human body can maintain thermal comfort and normal skin temperature by adjusting air temperature in high radiant temperature conditions.
• Findings are significant for understanding human physiological behavior and optimizing thermal environments.