LED Troffers – New DOE Report on Quality and Efficacy
Office Lighting Troffers are a huge installed base of lighting fixtures. This style of lighting fixture, provides economical general area lighting in many offices, schools, institutional, and commercial use spaces. As the most popular form of office lighting they are available in variety of styles and sizes, typically 2×4, 2×2, and 1×4 sizes with a wide variety of architectural styles. The optics systems in a troffer usually consists of simple diffussion lenses or louvers to spread the light,and to deliver diffuse work light to a work surface. In essence they are a simple low cost lighting source, designed to deliver light/ lumens over a large area efficiently.
Fluorescent Troffer Lamp Based Systems – Low Cost but with Disadvantages
The current installed base of office lighting troffers use linear fluorescent lamps. These lamps are relatively effective and of low cost to deploy. Many other lighting applications have been converted to LED lighting first, because they are of very high operational costs. For example parking lot lighting with HID lamp have a fast ROI and payback because of the number of hours per years they are used, and high wattages of older MH lamps. Because fluorescent troffers are realtively cost-effective, and provide a decent quality of light, this type of lighting has had a longer payback and has lagged in being replaced with more energy efficient lighting. This has set a high bar for LED troffers to replace traditional fluorescent lamp lighting.
LED Troffers – More Efficient and a First Choice for Retrofits or New Construction
In a new LED troffer product report by the DOE, significant gains and improvements to the efficiency of office lighting troffers are documented. Improvements to office lighting troffer quality have occurred, making LEDs as an office lighting source, a first choice when renovating or retrofitting an office space. LED troffers are now more energy efficient than a fluorescent lighting, while offering better color/ light quality and energy efficiencies. And further, these light sources are easily controlled, by advanced systems, such as daylight harvesting, occupancy controls, and individual dimming, that reduces the cost of office lighting. Additional advantages include no periodic re-lamping is needed, lighting quality is improved, and with much lower operating costs.
DOE Caliper Report on LED Troffers – Conclusions and Findings
The U.S. Department of Energy's CALiPER program's Report on LED troffers key findings are drawn from the LED lighting facts program database, which provides an overview and survey of the lighting market. The primary conclusions of the DOE troffer report are:
- LED troffers efficiency are now higher than a typical fluorescent lamp based system. Fluorescent troffers have a lighting efficiency of under 100 lumens/ watt. Most LED troffer systems are now above this threshold and premium LED troffer systems are approaching 125 lumens per watt. This translates into higher efficiency lighting, lower electricity costs for the office lighting system.
- LED troffers overcome disadvantages of older troffers without flicker, or the problems of fluorescent lamp fixtures. Fluorescent tubes, offer low cost lighting, but often at a low quality of lighting. These traditional fluorescent lamps can change color over time, require expensive re-lamping programs, and often flicker and buzz.
- LED office lighting troffers improve color quality, and energy efficiency that results in a superior lighting solution to fluorescent lamp troffers. Additional advantages include, availability in a wide variety color temperatures (CCTs,) to tune the lighting to office spaces need and design. Also, a typical LED troffers has a color rendering index (CRI) of over 80, providing better lighting performance.
As the DOE Caliper report demonstrates, in 2014 the mean efficacy for troffers was around 90 lumens per watt, today it's 102 lumens per watt. DOE primary conclusion is that LED troffers offer a compelling alternative to fluorescent troffers. Their report states this finding applies to both troffer luminaires and troffer retrofit kits, whose performance was indistinguishable.
In example, this LED Volumetric Troffer, provides light output at greater than 135 lumens per watt, and has a CRI value between 82 to to 84. This results in an office lighting solution that is not only more efficient than a fluorescent fixture, but produces higher quality illumination.