Assessing thermal comfort in wooden buildings: A visual perceptual analysis through physiological characterization

As the use of wood, a representative low-carbon building material, increases to reduce greenhouse gases, analysis of the impact of wood spaces on occupants is important for effective environmental planning. Therefore the study delved into the visual and perceptual warmth effects of wood through a comparative of thermal sensations in spaces featuring various finishing materials. A living space was created using concrete, wallpaper, brick, and wood, respectively, through virtual reality. A total of 30 subjects experienced the four living spaces through virtual reality, while subjective thermal sensation questionnaires and four physiological responses were measured. In a slightly cool environment based on predicted mean vote, subjects ranked the perceived warmth in the following order: wood > brick > wallpaper > concrete, with wood surpassing concrete by 3.30, in terms of visual warmth. These results support the hue-heat hypothesis that materials in the yellow-red spectrum are commonly perceived as warm. Moreover, the representative psychological impression associated with wood, such as warmth and coziness, considerably influences these perceptions. Importantly, the positive impact of the visual and perceptual thermal effects of wood, alongside the impression of space (as being comfortable, positive, and relaxed), notably enhanced thermal comfort, especially in cooler conditions. Furthermore, the subjective evaluation of the thermal environment was validated through correlation analysis involving thermal perception biomarkers and thermal comfort model. Indoor spaces with wood finishing materials were perceived as warm, and the possibility of reducing heating load and greenhouse gas emissions was suggested by improving thermal comfort during the heating season.