Influence of Air Temperature, Illuminance and Correlated Color Temperature on Thermal Perception

Balancing thermal comfort and energy efficiency in buildings remains a key challenge. While HVAC systems regulate temperature directly, recent studies suggest that visual factors—such as horizontal illuminance and correlated color temperature (CCT)—can influence perceived thermal comfort through psychological mechanisms. This study examined how these visual factors affect thermal sensation and comfort in cooling environments (26–30°C). A controlled climate chamber experiment was conducted with 54 healthy female participants under varying air temperatures, illuminance levels (100–2900 lx), and CCTs (2800–5200 K). Mean skin temperature increased with air temperature but remained unaffected by variations in illuminance or CCT, indicating stable physiological responses to visual conditions. However, higher illuminance and CCT levels led to enhanced sensations of coolness, particularly at 30°C. Visual comfort also improved slightly with increasing illuminance, while CCT effects on comfort were modest and dependent on air temperature. These findings suggest that adjusting the visual environment can enhance thermal comfort without changing actual temperatures, supporting higher cooling setpoints (around 28°C) and contributing to energy-efficient building design.