TECHNICAL MEMORANDUM: AN OPTIONAL METHOD FOR ADJUSTING THE RECOMMENDED ILLUMINANCE FOR VISUALLY DEMANDING TASKS WITHIN IES ILLUMINANCE CATEGORIES P THROUGH Y BASED ON LIGHT SOURCE SPECTRUM
|Publication Date:||27 May 2020|
This TM documents the fundamentals of visual efficiency, defines the EVE calculation method, and addresses practical concerns for implementation. The EVE method described herein should not be applied if any of these conditions apply:
• The task or tasks are covered by IES Illuminance Categories A through O for the Recommended Illuminance Target1
• The task is nonvisual in nature
• The task is not visually demanding (see Section 2.5)
• The application is exterior
• It is known that there are a high number of occupants with abnormal vision or poor ocular health
Further discussion of the preconditions for application of the EVE method is included in Section 4.5.
The method described in this TM is based on how the SPD of a light source affects the ability to discern achromatic visual detail. The SPD can also affect brightness perception, color rendering, discomfort glare, circadian rhythms, and other physiological outcomes; these factors are discussed only in limited detail in this TM. The decision to apply the EVE method is at the discretion of the specifier.