Daylighting Analysis

Incorporating natural daylighting into your building design provides many benefits, including improved employee productivity, reduced absenteeism, enhanced sales performance, and better student performance for schools. When daylighting is properly integrated with the necessary controls for the artificial lighting system and possibly the window shading system, significant energy savings may also be achieved. The newer energy codes and standards recognize the benefits of daylighting and now require inclusion of daylighting systems and controls for some applications.

Proper integration of daylighting systems requires careful consideration of the movement of the sun each day and all year, plus the occasional cloud, to maximize benefits and avoid problems that can result. Building designs must avoid direct sunlight on occupants or work surfaces, excessive heat gain through windows and skylights, and glare in the workplace in order to achieve success. New technologies present us with the tools to properly evaluate daylighting performance and address issues that arise.

CxE Group has extensive experience in properly modeling the performance of buildings and associated daylighting systems. Some of the tools we utilize include Radiance, Energy Plus, DOE-2, and SPOT Pro to both analyze the daylighting system performance as well as the net impact of reduced electric lighting and related solar energy on the heating and cooling loads in the building. A few of the many daylighting reference options available follow:

The Whole Building Design Guide, a program of the National Institute of Building Sciences (NIBS).

https://www.wbdg.org/resources/daylighting.php

Daylight Dividends, a website maintained by the Rensselaer Polytechnic Institute and supported by the US DOE, California Energy Commission, and many other state and national organizations.

http://www.lrc.rpi.edu/programs/daylighting/index.asp

Tips for Daylighting with Windows, developed by the Lawrence Berkley Lab and the US DOE.

https://windows.lbl.gov/daylighting/designguide/LBNL_Tips_for_Daylighting.pdf

Seventhwave (formerly Energy Center of Wisconsin) provides information for daylighting guidance.

http://www.seventhwave.org/daylighting

Daylighting in Schools: Improving Student Performance and Health at a Price Schools Can Afford by the National Renewable Energy Laboratory (NREL)

http://www.nrel.gov/docs/fy00osti/28049.pdf

Skylighting and Retail Sales – An Investigation into the Relationship Between Daylighting and Human Performance by Pacific Gas and Electric Company on behalf of the California Board for Energy Efficiency

http://www.pge.com/includes/docs/pdfs/shared/edusafety/training/pec/daylight/RetailCondensed820.pdf