2009 - Daylight Symposium
CLIMATE-BASED DAYLIGHT ANALYSIS FOR RESIDENTIAL BUILDINGS by John Mardaljevic
John Mardaljevic (UK)
Daylight Experts Ltd
This presentation describes a parametric study of daylight provision for two residential building types with and without various skylight configurations. Each of the ten building configurations was evaluated for all combinations of eight orientations and six climate zones. Thus daylight provision was determined for 480 unique cases using validated climate-based simulation techniques.
The evaluation of daylight provision was founded on the useful daylight illuminance (UDI) scheme, which determines the occurrence of absolute levels of illumination within four ranges: less than 100 lux; 100 to 500 lux, 500 to 2,500 lux; and, over 2,500 lux. The limits of these ranges are founded on human factors data from occupant surveys.
The study revealed the enormous variability in internal daylight provision that is revealed when realistic account is made of the naturally occurring sun and sky conditions as derived from standardised climate files. The study demonstrates that it is now possible to tailor the glazing and skylight design of a residential building to the specifics of the building aspect and the prevailing local climate.
John Mardaljevic, BSc, MPhil, PhD, Institute of Energy and Sustainable Development at De Montfort University, The Gateway, Leicester. Has a first degree in physics, and MPhil in astrophysics and a PhD in daylight simulation. His first significant contribution in the field of daylight modelling was the validation of the Radiance Lighting System under real sky conditions. John Mardaljevic has proposed a new climate-based metric called “Useful Daylight Illuminance” as a replacement for the daylight factor.