Modeling the comfort effects of short-wave solar radiation indoors

• SolarCal, a simplified whole-body model for the thermal comfort effects of shortwave solar radiation.
• Publicly available web interface for carrying out calculations using SolarCal http://smap.cbe.berkeley.edu/comforttool.
• SolarCal's ability to predict the impact of solar radiation on occupant thermal comfort verified against lab study.
• Several practical design scenarios where SolarCal can be effectively applied.
• Practitioner guidance for using the model and gathering the necessary data.

Exposure to sunlight indoors produces a substantial effect on an occupant's comfort and on the air conditioning energy needed to correct for it, yet has in the past not been considered in design or in thermal comfort standards. A public online model of the effects of solar radiation on human heat gain and comfort has been developed to make this possible. SolarCal is a whole-body model for ease of use in early design. Its predictions compare closely (<0.1 PMV mean absolute error) to results of a human subject test. It can be used to determine the allowable transmittance of fenestration in a perimeter office.