Posting Date | 19 October 2009
Validation/testing information | Daylight 1-2-3 uses a customized version of ESP-r that reads in RADIANCE/DAYSIM-based daylight coefficients and uses the occupant behavior model Lightswitch to predict the energy saving potential of automated lighting controls such as occupancy sensors and photocell-controlled dimming. Simulation outputs include the latest generation of climate-based daylight performance metrics such as continuous daylight autonomy, useful daylight index, and daylight saturation percentage as well as monthly energy loads for heating, lighting, and cooling. The effect of venetian blinds is modeled using the SKYVISION software. For an overview of the software, please refer to this paper.
Expertise required | Daylight 1-2-3 comes with an intuitive graphical user interface and extensive help files and should take you less than 30 minutes to learn.
Input of the tool | Building site and orientation, office dimensions, surface properties, lighting and blinds control systems, and occupant properties are specified through pull-down menus. Extensive help is provided throughout.
Output of the tool | False-color distributions of key daylighting performance metrics such as daylight autonomy, daylight factor, useful daylight illuminance and daylight saturation percentage. Monthly energy load charts for heating, lighting, and cooling.
Strengths | Lightswitch provides reliable predictions of lighting energy use in private offices considering occupant control of lighting and blinds. The underlying user behavior model is based on field study data. The tool should be used to estimate the energy saving potential of automated compared to manual lighting controls. Annual daylight availability and energy predictions are very accurate since they are based on RADIANCE and ESP-r.
Weaknesses | The number of supported building geometries and types is limited.
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