조도 기준

 

Footcandle Recommendations by Guth[1].pdf

 

 

 

 

http://www.gsa.gov/portal/content/101308

 

Table 6-3 Interior Illumination Levels (Average)

	Area	Nominal Illumination Level in Lumens/Square Meter (lux)
	Office Space
	Normal work station space, open or closed offices1	500
	ADP Areas	500
	Conference Rooms	300
	Training Rooms	500
	Internal Corridors	200
	Auditoria	150-200
	Public Areas
	Entrance Lobbies, Atria	200
	Elevator Lobbies, Public Corridors	200
	Ped. Tunnels and Bridges	200
	Stairwells	200
	Support Spaces
	Toilets	200
	Staff Locker Rooms	200
	Storage Rooms, Janitors’ Closets	200
	Electrical Rooms, Generator Rooms	200
	Mechanical Rooms	200
	Communications Rooms	200
	Maintenance Shops	200
	Loading Docks	200
	Trash Rooms	200
	Specialty Areas
	Dining Areas	150-200
	Kitchens	500
	Outleased Space	500
	Physical Fitness Space	500
	Child Care Centers	500
	Structured Parking, General Space	50
	Structured Parking, Intersections	100
	Structured Parking, Entrances	500
	1 Level assumes a combination of task and ceiling lighting where systems furniture is used. (This may include a combination of direct/indirect fixtures at the ceiling for ambient lighting.) NOTE: To determine footcandles (fc), divide lux amount by 11.

 

 

http://www.engineeringtoolbox.com/light-level-rooms-d_708.html

 

Measuring Units Light Level - Illuminance

Illumenance is measured in foot candles (ftcd, fc, fcd) (or lux in the metric SI system). A foot candle is actually one lumen of light density per square foot, one lux is one lumen per square meter.

• 1 lux = 1 lumen / sq meter = 0.0001 phot = 0.0929 foot candle (ftcd, fcd)
  
• 1 phot = 1 lumen / sq centimeter = 10000 lumens / sq meter = 10000 lux
  
• 1 foot candle (ftcd, fcd) = 1 lumen / sq ft = 10.752 lux

Common Light Levels Outdoor

Common light levels outdoor at day and night can be found in the table below:

Condition	Illumination
	(ftcd)	(lux)
Sunlight	10,000	107,527
Full Daylight	1,000	10,752
Overcast Day	100	1,075
Very Dark Day	10	107
Twilight	1	10.8
Deep Twilight	.1	1.08
Full Moon	.01	.108
Quarter Moon	.001	.0108
Starlight	.0001	.0011
Overcast Night	.00001	.0001

Common and Recommended Light Levels Indoor

The outdoor light level is approximately 10,000 lux on a clear day. In the building, in the area closest to windows, the light level may be reduced to approximately 1,000 lux. In the middle area its may be as low as 25 - 50 lux. Additional lighting equipment is often necessary to compensate the low levels.

Earlier it was common with light levels in the range 100 - 300 lux for normal activities. Today the light level is more common in the range 500 - 1000 lux - depending on activity. For precision and detailed works, the light level may even approach 1500 - 2000 lux.

The table below is a guidance for recommended light level in different work spaces:

Activity	Illumination (lux, lumen/m2)
Public areas with dark surroundings	20 - 50
Simple orientation for short visits	50 - 100
Working areas where visual tasks are only occasionally performed	100 - 150
Warehouses, Homes, Theaters, Archives	150
Easy Office Work, Classes	250
Normal Office Work, PC Work, Study Library, Groceries, Show Rooms, Laboratories	500
Supermarkets, Mechanical Workshops, Office Landscapes	750
Normal Drawing Work, Detailed Mechanical Workshops, Operation Theatres	1,000
Detailed Drawing Work, Very Detailed Mechanical Works	1500 - 2000
Performance of visual tasks of low contrast and very small size for prolonged periods of time	2000 - 5000
Performance of very prolonged and exacting visual tasks	5000 - 10000
Performance of very special visual tasks of extremely low contrast and small size	10000 - 20000

Calculating Illumination

Illumination can be calculated as

I = L_l C_u L_LF / A_l (1)

where

I = illumination (lux, lumen/m²)

L_l = lumens per lamp (lumen)

C_u = coefficient of utilization

L_LF = light loss factor

A_l = area per lamp (m²)

Example - Illumination

10 incandencent lamps of 500 W (10600 lumens per lamp) are used in an area of 50 m². With C_u = 0.6 and L_LF = 0.8 illumination can be calculated as

I = 10 (10600 lumens) (0.6) (0.8) / (50 m²)

= 1018 lux