Modeling solar radiation on a human body indoors by a novel mathematical model

Abstract Solar radiation affects occupant comfort and building energy consumption in ways that have received relatively little attention environmental design simulation. Direct, diffuse, reflected irradiation on the body warming effects can be equated to increases mean radiant temperature (MRT) of occupant's surroundings. A simplified occupant-centered model (SolarCal Model, i.e., SC Model) has recently been adopted ASHRAE Standard 55, followed by a comprehensive simulation procedure combining detailed room- manikin geometries using Daylight Coefficient Model (DC Model). This paper presents an intermediate-level mathematical (the HNU capable rapid annual calculations MRT increases. Both room are but consistent with those Model. Novel strategies calculation include sky-annulus fraction, virtual shadow, equivalent window. Modeled results compared simulated DC Radiance software, which is assumed accurate. The differences Delta direct, solar usually less than 1, 2, 0.5 °C between Models, respectively. For given position indoors, only needs 5 s obtain MRT, while about 7 min. provides simple practical way evaluate indoor environments at scale, fenestration, predict set-point changes HVAC systems.