LIGHTING AND POWER-PHYSICAL PLANNING OF LIBRARY-LIBRARY MANAGEMENT

The main activity in a library is reading for which adequate lighting is essential. Poor light strains the eyes and causes fatigue. On the other hand, glare is equally strenuous, and direct sunlight on the books is positively harmful. While maximum advantage should be taken of natural sunlight (electricity is costly and not hundred percent dependable in our country), and it should be judiciously supplemented with artificial light. Glare of the sun inside  the building should be avoided, so also shadows cast by artificial lighting particularly in the reading and service areas. There are certain areas where subdues lighting is preferable (e.g., micrographics section), and they may be suitably located. It is not only the quantity of light that is important, but also the quality of light, and a judicious choice has to be made to blend and complement natural light  and artificial light. In critical areas, provision  has to be made for emergency lighting specially if  the library activity is carried out  after daylight hours.  

Some important tips in this respect are: 

• Quality of light is more important than quantity or intensity.
• Quality depends on brightness contrast, colour contrast, intensity of illumination and absence of glare.
• Daylight has psychological value  
• Brighter sources are tolerable at large angle More the no of sources providing light the better
• Distance between light source and top of rack (min. 300 mm) is very important Reflecting power of wall, ceiling, furniture, etc. contribute to lighting 
• Advance planning for electrical distribution system  with sufficient outlets, location of master switch, cost & maintenance are important
• Recommended ratio of lighting is as follows: 

          The visual task (book): Immediate surrounding (table): 

          Background (wall) = 10: 3: 1 

                                         Lighting norms  

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