How Much Light Do I Need?

One of the most common questions that facility and operation managers ask is “How much light do I need to properly illuminate my facility?” Since 1958, the Illuminating Engineering Society has been publishing recommended illuminance levels for a multitude of tasks and facility types in table form.  The published tables provide guidance for both generic tasks and hundreds of very specific tasks.  In order to understand these tables, it’s best to start with an overview of how light is measured. This article gives a brief explanation of how light is measured and provides a handy table that can be used to determine how much light is needed in various types of facilities. If after reading this, you have any questions about the quantity of light you should plan for in your lighting retrofit project, don't hesitate to contact us. In the US, Illuminance is typically measured in foot-candles (fc).  One foot-candle (or footcandle) is the illuminance on a one square foot surface of which there is a uniformly distributed flux of one lumen.  A foot candle can also be defined as the amount of illumination the inside surface of an imaginary 1-foot radius sphere would receive if there were a uniform point source of one candela in the exact center of the sphere .  You may also come across measurements taken in lux.  In the lighting industry, we approximate 1 foot-candle to equal to 10 lux. The table below can be used as a general guideline to determine how much light you need for your facility.

Application	Foot-Candle Level
Aircraft Hangar	75-100
Assembly/Packaging - Medium	50-70
Assembly/Packaging - Fine	75-100
Auto Service Garage	60-80
Auto Showroom	50-80
Body Shop	80-120
Church	20-25
Cooler or Cold Storage Room	10-30
Engineering and Drafting	50-125
Food Processing	50-100
Foundry	40-60
Gymnasium Lighting - Recreational	30
Gymnasium Lighting - Elementary or Club	50
Gymnasium Lighting - High School	80
Hockey - Recreational	20-50
Hockey - Professional	50-100
Horse Riding Arena	25-50
Loading Dock	30-50
Machine Shop - Rough Detail	50-75
Machine Shop - Medium Detail	75-100
Machine Shop - Fine Detail	100-200
Manufacturing - Rough Detail	50-75
Manufacturing - Medium Detail	75-100
Manufacturing - Fine Detail	100-150
Multipurpose Room	30-75
Office	60-75
Parking Garage	15-30
Retail - Average	50-80
Retail - Super Center	80-120
Swimming Pool - Recreational	50
Swimming Pool - Club	75
Swimming Pool - Tournament	100
Warehouse - Active	20-30
Warehouse - Inactive	15-20
Woodworking Shop	60-80

I hope this article has helped to answer how much light is needed in your facility.  As always, our experts are happy to help guide you through your lighting retrofit.  Don't hesitate to contact us if you have any questions.