Friday 21 March 2025
The quest for thermal comfort has long been a challenge in outdoor environments, particularly during extreme heat waves. Designers of built spaces have traditionally focused on whole-body temperatures, neglecting the complex interactions between the human body and its surroundings. A new study published in a scientific journal aims to rectify this oversight by developing methods to quantify shortwave and longwave irradiation distributions across the human body.
The researchers created an innovative thermal manikin with a white-coated side, allowing them to separate spectral components of radiation. This enabled them to measure the distribution of shortwave and longwave irradiation on different parts of the body. The study also utilized radiometer measurements in six directions as input for computational simulations, providing a comprehensive understanding of these complex thermal interactions.
The researchers conducted outdoor measurements at various sites with different levels of shading, from sunny to fully shaded areas. They found that the two methods produced closely aligned results, highlighting the strengths and limitations of each approach. This work has significant implications for designing built environments that optimize human thermal comfort in outdoor settings.
One of the key challenges in this research was addressing the thermal resistance added by fabric. The team developed a modification to their manikin control software to account for these resistances, ensuring accurate measurements. They also created a custom-made onesie with a specific shortwave and longwave absorptivity, allowing them to measure the effects of different fabrics on human thermal comfort.
The study’s findings have important implications for the design of clothing and textiles. By understanding how different materials absorb and reflect radiation, designers can create garments that better regulate body temperature in extreme environments. This could be particularly crucial for workers in outdoor industries, such as construction or agriculture, who are often exposed to intense heat and sunlight.
The researchers also explored the effects of fabric color on human thermal comfort. They found that darker colors tend to absorb more radiation, while lighter colors reflect it. This has significant implications for designing clothing and textiles that can help mitigate extreme heat exposure.
The study’s results demonstrate the importance of considering both shortwave and longwave irradiation in outdoor environments. By understanding these complex interactions, designers can create built spaces that are not only aesthetically pleasing but also thermally comfortable. As our world becomes increasingly urbanized, this research has significant implications for creating healthy and sustainable living environments.
In addition to its practical applications, this study highlights the importance of interdisciplinary collaboration between engineers, scientists, and designers.
Cite this article: “Quantifying Shortwave and Longwave Irradiation for Thermal Comfort in Outdoor Environments”, The Science Archive, 2025.
Thermal Comfort, Human Body, Radiation, Outdoor Environments, Built Spaces, Manikin, Radiometer Measurements, Computational Simulations, Fabric Resistance, Textile Design.
