Trends in Educational Lighting Systems
- By Peter Murphy
- November 1st, 2001
There is a wide array of innovative lighting products that incorporate new technologies designed to both save energy and improve lighting quality. The tough job for facility designers is deciding which ones make the most sense. Below is an overview of the most important lighting innovations available to reduce cost or provide an optimal learning environment.
Direct-Indirect Suspended Fluorescent Lighting
The evidence is clear: direct-indirect (D/I) suspended lighting systems provide the highest quality illumination for most learning or work environments. First introduced a decade ago, D/I has now become a preferred choice for offices, classrooms, libraries and laboratories. Suspended from the ceiling, D/I systems combine the ambience of indirect illumination (bounced up and off the ceiling) with energy-efficient direct illumination (aimed downward to the desktop to provide visibility for reading and writing).
What makes D/I systems superior for educational environments? There are three factors.
1. Balanced, uniform illumination throughout the space. The combination of indirect, reflected light and controlled, direct light creates a uniquely comfortable luminous environment for the teaching/learning process. The addition of controlled downlight delivered to the desktop or study table means excellent visibility for visual tasks, without the usual harsh shadows of direct-only lighting systems. And because the fixtures carefully control this direct illumination, the problem of reflected glare in computer monitors is avoided.
2. Having well-lit ceilings and wall surfaces gives the space an uplifting feeling that has been shown to enhance the physical and psychological well-being of the occupants.
3. Finally, D/I systems are more energy efficient than indirect-only systems because less light is absorbed by the ceiling.
For the budget-minded, there is little doubt that recessed troffers cost less to purchase than suspended lighting. However, the trade-off is a reduction in the quality of illumination. In addition, it is important to note that, while troffers appear cheaper at the outset, the price gap narrows when contractor installation costs are factored into the initial purchase price. A more complete analysis would include the maintenance and energy costs for the system’s lifetime.
Lower-Cost Suspended Linear Lighting
Responding to the budgetary realities of the education sector, lighting manufacturers have worked hard to reduce the cost of D/I classroom lighting solutions. A recent innovation involves the use of lower-cost steel in the manufacture of linear lighting fixtures. The technical barrier here was ensuring the steel housings would not sag or twist over long fixture lengths. This challenge overcome, suspended steel systems are now a viable option for projects in which cost is a major constraint. At the same time, the extruded aluminum systems preferred by many lighting designers for their superior durability and longevity have also come down in price. Aluminum D/I systems are now available at or near the same cost as competing steel systems.
High-Efficiency Optical Systems
Improvements in both fluorescent lamp technology and optical system design have also reduced the number of fixtures and lamps required in each setting. New, brighter lamps, combined with precision optical control systems, have made it possible to light a standard-sized classroom with two rows of suspended D/I lighting versus the three rows required previously. This leads to a one-third reduction in the purchasing requirements. It also reduces the number of fixtures that need to be cleaned and maintained. Fewer fluorescent tubes means that relamping costs less and takes one-third less time. This doesn’t sound like much but, across 20 years, maintenance costs are a significant portion of the lifetime costs of ownership.
Factory Wiring and Quick-Connect Systems
Why spend money having the electrical contractor learn how to wire the lighting system on your jobsite? To save costs on the jobsite and ensure the system is installed properly, many manufacturers prewire the lighting in the factory. Similarly, many have now devised quick-connect technologies to further reduce installation times and save on contractor costs.
Occupancy and Daylight Sensors
Leaving lights burning when classrooms or labs are unoccupied is a tremendous waste of electricity. The California power crisis pointed out how important it is to curb energy waste, wherever it occurs. Unoccupied classrooms, labs and libraries are primary targets for energy-saving technologies.
Today, occupancy sensors automatically sense when no movement is occurring in a space and turn off or dim the lighting to a minimum level for safety. Once someone enters the classroom or lab, the lights turn back on automatically. Similarly, daylight-dimming sensors allow the school to "harvest" free daylight that comes in through the window by automatically turning the electric lights down when they are not required. Studies have found that occupancy sensors can cut electricity usage by 50 percent.
What About the New Fluorescent Lamps?
Educational facility designers have heard about the new T5 or T5 high-output lamps. Interesting as these are, they are still, for the most part, appropriate only for more innovative architectural projects. For university settings, the well-established T8 lamp is the best choice. That said, any lighting system using older (and now outlawed) T12 lamps should make the changeover to a new T8 system as fast as possible to take advantage of the energy savings they offer.
The exciting new technologies discussed above are revolutionizing the quality and cost of educational lighting. Direct/indirect lighting is probably the most important advance that facility planners need to be aware of during the budgeting process. Although recessed troffer systems are cheaper, they can’t match the quality illumination provided by D/I fixtures.
Peter Murphy is president of Ledalite Architectural Products, Inc., in Langley, British Columbia . He can be reached at 604/888-6811 or .