160%
140%
120%
100%
80%
60%
40%
20%
0 0.195
The Lighting Handbook
Ambient
condition
Maintenance interval
recommended
Working areas Reference main-
tenance factor
Very Clean (VC) years Cleanrooms, data centres,
assembly workstations for
electronic components
0.5 2.80
Clean (C) years Offices
Schools
0.0 2.57
Soiled (S) year Steel works
Chemical plants
Foundries
Welding shops
Grinding shops
Wood processing
0.50
According CIE volume 97, “Maintenance indoor electric lighting systems”, 2005
In case you are not familiar with the appli
cation, the following standard
values apply; however, the tables below will help you calcu
late the accurate
maintenance factor according formula (2).0 1.5
Example:
Luminaire maintenance: every year
Room surface maintenance: every years
Lamp replacement: every years
Faulty lamp replacement: immediately
= Em
= Enew
years
Environmental conditions
.0 3.67
Normal (N) years Shops
Laboratories
Restaurants
Warehouses
Assembly bays
0.5 1.5 3
