How beneficial is LED lighting? At Cherokee Elementary School in Scottsdale, Ariz., new-fangled LED lighting fixtures not only save energy, they also prevent special education students with autism from being bothered by fluorescent lighting. Researchers maintain that individuals with autism are more vulnerable to the sub-visible flicker of direct fluorescent lighting, which can cause headaches, eyestrain and increased repetitive behavior.
In a pilot project, Scottsdale Unified School District replaced 69 2×4-foot fluorescent lighting troffers in four special education classrooms with 60 2×2-foot flat-panel LED fixtures from lighting manufacturer MaxLite. The install has the added benefit of energy savings. According to Charlie Bowers, Arizona Business development manger for installer Centennial Contractors, the school saw energy savings of about 60 percent in areas with the new LED fixtures. Most importantly, these fixtures do not flicker when fully dimmed, a quality that is important in a special needs classroom.
MaxLite rep Adam Robbins from lighting supplier Perseid LED specified the MLFP22D4535 2×2 Direct Lit Flat Panels. These panels each emit 3,850 lumens of brightness while using just 45 watts. The lumen power is far less than the 8,000 lumens the school’s previous fluorescent troffers offered, but those classrooms had been overly lit.
“When a lighting layout was done, nine fixtures were determined to be unnecessary to adequately light the areas,” says David Delgado, MaxLite lighting applications engineer.
In a single room with 22 fixtures, the new products were able to reduce the lumen output by 121,000 lumens for substantial energy savings. The room initially had a light intensity of 65 foot-candles. After the install, the room was down to 42 foot-candles at the desktops, meeting Arizona state standards.
Designed for drop-in ceilings, the LED flat panels were offered in the correlated color temperature (CCT) of 3500K, which emits a “soft white” light. The lights have a CRI (Color Rendering Index), a measurement of color accuracy, of >80, which is considered by lighting experts to be good, with 90 to 100 considered excellent. An IR remote allows teachers to adjust the lighting levels to meet the changing needs of the classroom or to alter children’s moods. For additional energy savings, the fixtures are dimmed or switched off when the rooms are not in use.
Replacement Without a Hitch
Each of the 2×4-foot troffers with T8 fluorescent tubes was completely removed, along with its accompanying ballast, and made available to be used by the school system elsewhere. Although the MaxLite Flat Panels require a minimal installation depth of 4 inches, replacement went without a hitch, according to Bowers, as they were easily connected to the existing power lines and whips cables.
Each of the new fixtures contains a light board with 142 individual LEDs and its own driver. The face frame is satin polycarbonate, the housing is steel, and the lens is translucent white polystyrene. The fixtures are IC-rated for contact with insulation after installation, and up to 20 fixtures can be linked to one “master” in a room.
The flat-panel fixtures were chosen over LED replacement kits and LED tube lighting such as T8 tubes, which Bowers says lack the performance and reliability of designed fixtures such as flat panels. “We do not use LED tubes at all. They’re just not dependable enough.”
LED flat panels create a more striking, high-end skylight effect, while retrofit kits and LED tubes resemble fluorescent lighting products.
According to a CALiPER (Commercially Available LED Product Evaluation and Reporting) program study on recessed LED troffer lighting, dedicated LED troffers are ready to compete with fluorescent troffers in terms of efficacy. They also address many lighting quality issues such as glare, light distribution, visual appearance and color quality.
Advantages to switching to long-life LED products are that they will require less maintenance and produce a flicker-free light for many years to come. The MaxLite Direct Lit Flat Panels are rated for 50,000 hours.
Bowers says LED fixtures are now about a third of the price they were three years ago. “In addition, we are receiving utility rebates [from Arizona Public Service] for the energy conservation measures, and those are passed along to the owner to help offset the cost of the lighting retrofit.”