Modeling Daylight

Evaluating the annual energy performance of daylighting systems used to take days and even weeks for a single point-in-time calculation. LBNL researchers are developing and validating the time-efficient simulation tools (i.e., Radiance, EnergyPlus) needed to evaluate the annual daylighting and window heat gain (and therefore, total energy use) impacts of fenestration systems, including more recent optically complex fenestration systems (CFS).

Radiance rendering of an open plan office with a microprismatic daylighting film in the clerestory portion of the window.  The left images illustrate how the three-phase approach renders glare sources with considerably less accuracy than the recently developed five-phase method (falsecolor luminance images are shown in the lower row). Improvements to modeling tools like this can help industry develop innovative daylighting and solar control technologies for buildings.