Office spaces built prior to the 1980s were primarily designed to provide adequate illumination for reading of documents and printed materials. During the 1980s, as typewriters were being exchanged for computers, the need for redesign or rearranging office lighting was typically overlooked. Computer monitors serve as a source of lighting and do not require additional illumination from other sources. The Illuminating Engineers Society (IES) recommends a range of illumination for modern office systems between 300-750 lux, however office operations which primarily involve computer-based tasks can significantly reduce the need for overhead lighting to a range of 300-500 lux. Older lighting systems which were originally designed to accommodate paper reading tasks typically produced light levels TWICE this range, between 750-1000 lux.
Dimming or turning off excessive overhead lighting and employing “task lighting” or counter-level light sources is often a better solution than simply bathing an office space in the excessive and harsh glow of banks of overhead fluorescent lights.
Offices which are over illuminated offer significant opportunities for energy savings through the reduction of the number of overhead lighting fixtures and the employment of lamps with focused light sources for the illumination of printed materials. Desk lamps or other sources of “soft lighting” can easily be used to illuminate documents, which avoid the employment of excessive overhead lighting near computer monitors. Do not conform to factory settings on computer screens – change them such that the monitor works for the particular user, as lighting demands vary widely between individuals. Dimming or turning off excessive overhead lighting and employing “task lighting” or counter-level light sources is often a better solution than simply bathing an office space in the excessive and harsh glow of banks of overhead fluorescent lights.
Energy audits should not only focus on lighting fixture efficiency, such as substitution of T12 fluorescent lamps with T8 or T5 fluorescent lighting fixtures or the implementation of much more advanced and energy efficient LED light sources. Energy audits should also focus on the reduced need for lighting and address these needs on a “room or area specific” basis.