For example, consider the ubiquitous fluorescent troffer fixtures in hospital patient rooms. Changing a fluorescent bulb is a dangerous affair, involving ladders and maintenance people. If the bulb breaks the patient must be evacuated from the room, as there is health risk involved from mercury contamination, not to mention the small slivers of glass that can damage expensive medical equipment. Fluorescent T8 tubes have a mean-time-to-failure (MTTF) of 25,000 hours. MMTF is defined as the time when half of the light bulbs are dead. This means that changing bulbs is a constant problem. Within the first year of operation of the fluorescent lights, the hospital's maintenance crew will have had to change 30% of the fluorescent tubes in hundreds of the hospital's troffer fixtures. For the hospital with LED troffers, however, the maintenance crew will not yet have had to touch any of the LED lamps until 100,000 hours (more than 10 years) have passed. This represents a major cost savings and allows the maintenance department to focus on more important activities.
Quality of lighting
LED lights don't buzz and flicker the way fluorescents do. Studies indicate that children with Down's syndrome learn better when their environment is lit by LEDs. There is a plethora of information about the negative effect fluorescent lighting can have on photosensitive individuals, including the inducement of seizures. The Job Accommodation Network (http://www.jan.wvu.edu) lists reduction or elimination of fluorescent lighting as an appropriate accommodation for many conditions, including epilepsy.
LEDs offer flexibility in light-level control and color temperature not available with fluorescent technology. It is well known that human beings respond to intensities and color temperatures of light differently depending on time of day and activity. During intense activities mid-day, such as during examinations and in surgery, high light levels and cool color temperatures are preferable. During evening hours, and where comfort and relaxation are desirable, such as in hospital lounges, waiting rooms, and patient rooms, (figure 1) warm color temperatures are more acceptable. LED lighting is now available that reproduces this wide range of intensity and color to provide environments that are always illuminated at optimum levels for maximum productivity and comfort.
LED Cove lighting provides a warm, inviting ambiance in waiting rooms and lounges, without the need to change bulbs for over 10 years
Applications
The healthcare environment is unique in that a typical building comprises many different physical areas that have dramatically different lighting requirements. These can range from the loading dock, to the patient's room, to the operating room. LED lighting solutions are finding their way into all of these applications, although some are ahead of others. The more common applications include LED cove lighting (lounges, hallways; figure 2), LED task lighting (labs, pharmacies; figures 3, 4), LED high bays and linear LED fixtures (hallways, lobbies, parking garages), low bay LED fixtures (stairwells, loading docks), and LED troffer fixtures (patient rooms, exam rooms, cafeterias).
