Q: What standards are used in Lumen-Micro's calculations and have the predictions been compared to physical measurements?

A: Lumen-Micro employs calculation techniques that adhere to generally accepted practices in the illumination engineering profession both in the United States and internationally. The techniques used for the electric lighting calculations are derived from general radiative transfer theory for diffuse environments and have been compared and verified against physical measurements by Lighting Technologies1 and independent parties2 for both empty rooms and rooms containing obstructions. The daylighting calculations use sun and sky models accepted by both the IESNA3 and the CIE4. Furthermore, the daylight calculations have been compared and verified against physical measurements. The results of said comparisons as well as a full description of the calculation techniques used to calculate daylighting levels were presented at Lux Europa in 19935.

1. Livingston, L., "Lumen-Micro 5.03, Comparing Measured and Predicted Values for Electric Lighting," Lighting Technologies Internal Report, August, 1991.
2. Raitelli, M.R., Carter, D.J., "A Designer's Guide for Electric Lighting in Obstructed Interiors," Proceedings of Lux America Congress, Sao Paulo, Brazil, August, 1992.
3. IESNA Calculation Procedures Committee, "Recommended Practice for the Calculation of Daylight Availability," IES-RP-21-1994.
4. "International Recommendations for the Calculation of Natural Daylight," CIE Publication No. 16, Paris: International Commission on Illumination, 1970.
5. Jongewaard, M., "Daylight Calculations, Measurements and Visualization in Non-Empty Rooms," Proceedings of Lux Europa, Edinburgh, Scotland, 1993.