Improvement of energy performance and quality of indoor space can be achieved through good daylighting. We apply Radiance software through the IES dynamic simulation model to establish levels of daylight and test advanced daylighting techniques such as light-shelves, skylights and daylight harvesting. Daylight modelling takes into account external shading, blinds, different glass types and changes to building form.
We are able to produce photometric simulations using advance ray-tracing techniques to assess the impact of daylight reflecting multiple times within a space producing photo-realistic images and detailed graphics of the daylight penetration achieved. We use the model to assess daylight levels based on real weather data to inform the design of the building form and optimise the potential savings in artificial light loads against any increase in unwanted heat gain or losses through glazing.
Solar Tracking – we can use the dynamic model to assess the impact of the sun’s path on the building exterior and interior and inform passive solar studies, solar shading decisions and enhance the accuracy of the thermal simulations by taking into account solar shading.
Climate Based Daylight Modelling
As part of the Priority Schools Building Programme, Climate Based Daylighting Modelling (CBDM) is now required to be assessed.
CBDM is an annual time-series daylighting study using sun and sky conditions derived from actual weather data for the site. It takes account of the quality and quantity of sunlight and daylight rather than the traditional daylight factor analysis which is a numerical process based on a static overcast sky condition.
This allows the analysis to provide far greater detail about the natural light distribution and intensity with early analysis driving the building design to maximise the use of daylight to the occupied spaces.
We have worked closely with IES with the development of this calculation methodology and tested various iterations in order to achieve compliance with each orientation option of a building for a variety of façade options.