This is a legacy version of the WELL Building Standard. Please check the latest version here.
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  2. Electric light glare control

Electric light glare control

Features>Light>55. Electric light glare control

55. Electric light glare control

Non-diffuse bright indoor lights create uneven levels of brightness in the visual field. The resulting glare can cause visual fatigue and discomfort.

This feature sets limits on glare based on measures of luminous intensity, or luminance per area of light source. This quantity, often given in cd/m² or foot-lamberts, can be measured directly or calculated from lighting specification sheets with sufficient detail. Light fixtures of greater luminous intensity require a greater shielding angle to reduce the likelihood of creating direct glare for occupants.

Part 1: Lamp Shielding

Lamps with the following luminance are shielded by the angles listed below or greater:

a) Less than 20,000 cd/m² [5800 foot-lamberts], including reflected sources: no shielding required.
b) 20,000 to 50,000 cd/m² [5800 to 14,500 foot-lamberts]: 15°.
c) 50,000 to 500,000 cd/m² [14,500 to 145,000 foot-lamberts]: 20°.
d) 500,000 cd/m² [145,000 foot-lamberts] and above: 30°.
Part 2: Lamp Shielding in Sport Centers

The following requirements are met:

a) All lights in the field or arena are shielded such that the sources not in direct line of sight of spectators within 30 m [100 ft].
Skeletal
Muscular
Nervous

Applicability Matrix

Core & Shell New Construction WELL Interiors
Part 1: Lamp Shielding - P P
Part 2: Lamp Shielding in Sport Centers - - -
Commercial Kitchen Education Multifamily Residential Retail
Part 1: Lamp Shielding O P P O
Part 2: Lamp Shielding in Sport Centers - - - -

Verification Methods Matrix

Letters of Assurance Annotated Documents On-Site Checks
PART 1 (Design)
Lamp Shielding 		Architect Spot Measurement

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licht.de. licht.wissen 04: Office Lighting: Motivating and Efficient. Frankfurt; 2014: 35.
55.1.b

To avoid glare caused by bright light sources, lamps should be shielded. The minimum shielding angle for lamp luminance of 20,000 - 50,000 cd/m² is 15°.
55.1.c

To avoid glare caused by bright light sources, lamps should be shielded. The minimum shielding angle for lamp luminance of 50,000 - 500,000 cd/m² is 20°.
55.1.d

To avoid glare caused by bright light sources, lamps should be shielded. The minimum shielding angle for lamp luminance of 500,000 cd/m² and above is 30°.
Features>Light>55. Electric light glare control