Sustainable Lighting Design & Daylighting Autonomy in Cymap

By Stuart Morgan 

Most engineers are aware of the Part L Building Code requirements for lighting in non-residential buildings.

However, engineers still view this topic simply as a means of achieving a minimum watts per square metre.  But a lighting design that includes natural daylighting and energy efficiency control measures, has obvious economic benefits for building owners and managers, as well as benefits for users of the spaces.  Cymap can not only assist with these basic building regulation requirements, but can also go a long way to help in achieving LEED/BREEAM credits for sustainable lighting design in buildings.

Cymap’s integrated electrical software - Lighting/Electrics/Wiring - offers many powerful design, analysis and control options.  The building model with rooms, windows, doors can be taken from the architectural model and automatically imported from Revit/ArchiCAD, or any other CAD software that supports the gbXML file format.  Immediately you can experiment with different glazing options and BRE 498 Control Method for your rooms/spaces.  The materials databases can be set up with appropriate visible light transmission factors for the selected glazing options, which will subsequently be used in your daylight calculations.

Using the LENI calculation, Cymap Lighting takes into account average daylighting levels within each space, depending on the glazing system selected and using templated room design data will apply a daylighting autonomy calculation to evaluate the number of hours a year each space will be required to be run in order to meet the average room design lighting level.  You can see, highlighted below, the difference between a room not using daylighting controls, around 1500 hours of operation per year, to a room with daylighting controls applied, 200-300 hours per annum.

As part of an integrated suite of tools, you can carry out an analysis of this type, and develop the design to a point where the light fittings are connected to your distribution boards and finally carry out cable sizing calculations by importing all of the circuit data into the Wiring program for 17^th Edition cable sizing. . But more on that in a future Blog.