Simulation of visual and thermal comfort related to daylighting and solar radiation in office buildings

The research we develop consists in evaluating "radiative comfort" during no heating periods in dwelling space and particularly in office buildings. The expression "radiative comfort" is used to characterize the thermal and visual component of the feeling of people set in indoor environments submitted to sky and sun irradiation by bay windows. Two numerical models, one for the visual aspect (Genelux) and the other for the thermal aspect (TRNSYS), have been connected together to carry out simulations on radiative comfort in office buildings. From the analysis of these results, we present :

• the time evolution study of visual and thermal discomfort situations. It shows that discomfort glare due to daylighting always anticipates overheatings related to direct and diffuse solar radiation;
• the reduction of overheatings resulting of a prior modification of the window’s transparency based only on visual constraint;
• the implicit relationship between visual and thermal aspects in radiative comfort. Hence, visual parameters only could be used as a means for maintaining both visual and thermal components within acceptable limits; 
• the possibility to detect radiative discomfort situations from easy measurements of illuminances, which are the foundings of a « glaremeter » based on a simple measurement concept. Associated with a measure of operative temperature, it could constitute a complete but cheap metrological system of radiative comfort.