Question

How many footcandles are needed for a sewing factory with low contrast and small clothing materials?  The average age of workers is 40.  Assume the speed and accuracy of the work is critical.  Indicate which lighting category and correction factor you use to answer the question.

How many footcandles are needed for the lobby of a nursing home?  Indicate which lighting category and correction factor you use to answer the question.

Answer 1

Footcandles are the most common unit of measure that is used by lighting professionals to calculate light levels in businesses and outdoor spaces. A footcandle is defined as the illuminance on a one square foot surface from a uniform source of light.

Usually, in an industry or a place where the performance of visual tasks of low contrast or very small size takes place, the range of required illuminance is - 100-150-200 footcandles.

For the performance of visual tasks of low contrast and very small size over a prolonged period, the range of illuminance is 200-300-500 footcandles.

So, in a sewing factory with low contrast and small clothing materials, with the average age of workers being 40 and where the speed and accuracy of the work are critical, it is important that the illuminance is of category F (100-150-200 footcandles) or category G (200-300-500 footcandles).

The lobbies of Nursing homes need to have an illuminance range of category C (10-15-20 footcandles) during daytime and category B ( 5-7,5-10 footcandles) during night time.