IESNA Indoor Lighting Recommendations

Table 1: Illuminance Categories
Illuminance Category	Activity Type	Footcandle Range	Workplane Reference
A	Public Space, dark surroundings	2-3-5	General lighting throughout space
B	Simple orientation, short temporary visit	5-7.5-10
C	Visual tasks only occasionally performed	10-15-20
D	High contrast or large tasks	20-30-50	Illuminance on task
E	Medium contrast or small tasks	50-75-100
F	Low contrast or very small tasks	100-150-200
G	Low contrast or very small tasks for a prolonged period	200-300-500	Illuminance on task, both general and supplementary components
H	Very prolonged and exacting tasks	500-750-1000
I	Extremely low contrast and small very special tasks	1000-1500-2000

Table 1a. Recommended Illumination Levels
Task		IESNA Illuminance Category	Recommended Footcandles^*
Drafting	High contrast (ink, soft lead)	E	50-75-100
Drafting	Low contrast (hard lead)	F	100-150-200
Inspection	Simple	D	20-30-50
	Moderate	E	50-75-100
	Difficult	F	100-150-200
Machine Work	Medium, grinding, etc.	E	50-75-100
Materials Handling	Picking, packing, wrapping, labeling	D	20-30-50
Other	Lobby, corridor, waiting area	C	10-15-20
	Toilets, rest rooms	C	10-15-20
	Teller stations, ticket counters	E	50-75-100
Reading	General	D	20-30-50
	Soft pencil (#2), pen, good copies, keyboards, > 8 pt. type	D	20-30-50
	Hard pencil (#3), phone books, poor copies, < 8 pt. type	E	50-75-100
Schools	Science laboratories	E	50-75-100
Storage	Inactive	B	5-7.5-10
	Active, large items	C	10-15-20
	Active, small items	D	20-30-50
^*See Table 2 for weighting factors used to determine which of the three designated levels to choose.

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Table 2. Determining Illuminance Values
a. General Lighting Throughout Room (footcandles)
Weighting Factors				Illuminance Categories
Average of Occupants' Ages		Average Room Surface Reflectance (Percent)		A		B		C
Under 40		Over 70		2		5.0		10
		30-70		3		7.5		15
		Under 30		3		7.5		15
40-55		Over 70		3		7.5		15
		30-70		3		7.5		15
		Under 30		3		7.5		15
Over 55		Over 70		3		7.5		15
		30-70		3		7.5		15
		Under 30		5		10.0		20
b. Illuminance on Task (footcandles)
Weighting Factors				Illuminance Categories
Average of Workers' ages	Demand for Speed and/or Accuracy*		Task Background Reflectance (Percent)	D	E	F	G**	H**	I**
Under 40	NI		Over 70	20	50	100	200	500	1000
			30-70	20	50	100	200	500	1000
			Under 30	30	75	150	300	750	1500
	I		Over 70	20	50	100	200	500	1000
			30-70	30	75	150	300	750	1500
			Under 30	30	75	150	300	750	1500
	C		Over 70	30	75	150	300	750	1500
			30-70	30	75	150	300	750	1500
			Under 30	30	75	150	300	750	1500
40-55	NI		Over 70	20	50	100	200	500	1000
			30-70	30	75	150	300	750	1500
			Under 30	30	75	150	300	750	1500
	I		Over 70	30	75	150	300	750	1500
			30-70	30	75	150	300	750	1500
			Under 30	30	75	150	300	750	1500
	C		Over 70	30	75	150	300	750	1500
			30-70	30	75	150	300	750	1500
			Under 30	50	100	200	500	1000	2000
Over 55	NI		Over 70	30	75	150	300	750	1500
			30-70	30	75	150	300	750	1500
			Under 30	30	75	150	300	750	1500
	I		Over 70	30	75	150	300	750	1500
			30-70	30	75	150	300	750	1500
			Under 30	50	100	200	500	1000	2000
	C		Over 70	30	75	150	300	750	1500
			30-70	50	100	200	500	1000	2000
			Under 30	50	100	200	500	1000	2000
		* NI = Not Important, I = Important, and C = Critical ** Obtained by a combination of general and supplementary lighting.

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