With federal and state regulations restricting lighting energy use in new and renovated structures, more than 16,000 attendees at Lightfair International 2006, held May 28-June 1 at the Las Vegas Convention Center, scoured the aisles to find the latest offerings in energy-efficient lighting system products. Why the hectic search? In particular, this trend is undoubtedly linked to the adoption of ASHRAE 90.1-2004, which imposes tough standards on maximum watts-per-square-foot levels for lighting systems in commercial buildings. But that's not all. The Energy Policy Act of 2005 includes a $1.80-per-square-foot tax deduction for new construction exceeding ASHRAE standards, and a specific deduction of up to $0.60 per square foot for interior lighting systems. In addition, the Department of Energy has set the fluorescent ballast efficiency factors high enough that the vast majority of magnetic ballasts, including those operating energy-saving T12 lamps, will no longer qualify. Couple that with the promotional benefit of designing a “green” building (the U.S. Green Building Council's Leadership in Energy and Environmental Design program that rates sustainable design), and the reason for the hunt becomes rather obvious.
In addition to the usual spotlight on efficient lamps and fixtures, a variety of new and enhanced lighting control equipment was highlighted at the show. Advanced lighting control is a concept taking hold, since up to six different energy-slicing strategies can be addressed. In addition to the three familiar control methods — occupancy control, time-scheduled switching, and daylight harvesting with a photocell sensor — task tuning, personal dimming control, and load shedding can be configured using software, either locally or from a central location.
Many manufacturers presented digital control devices featuring keypads, LCD displays, and touch screen graphics. The familiar and popular 0-10 V analog control and a variety of digital communication methods, such as DALI, Lonworks, and Modbus TCP/Ethernet, were demonstrated on the exhibit floor, some using Cat. 3 or Cat. 5 data cabling products for signal transmission.
Networked systems. Hubbell Building Automation, Austin, Texas, displayed a wall switch occupancy sensor product line, known as LightHawk, that uses passive infrared, ultrasonic, and dual-technology for optimum detection and false trip immunity. The devices have selectable operating modes, including automatic on/off or manual on/automatic off, and an integral photosensor for automatic daylight harvesting. The company also offers an LX lighting control system that uses a portable touch screen tablet with a graphical user interface to simplify configuration and management. A topology-free, polarity-insensitive two-wire LonWorks-based communications network connects wall switch stations, sensors, and lighting loads.
Electrical contractors should be familiar with many of the components in Square D's new lighting control system, since it mates the Powerlink system to a line of Clipsal input devices, such as a wall-mounted keypad that can control up to eight lighting functions. Four of the five keypad buttons are programmable, with the fifth serving as a scroll button to toggle between two “pages” of the keypad. Each button displays editable test or graphics to indicate the room or the custom-designed lighting system it controls. A wall-mounted or desktop touch screen adds convenience to the lighting control system.
The controller mounts to a standard panelboard, such as a three-pole branch breaker, or can be placed in its own enclosure. A Modbus TCP/Ethernet network (Cat. 5 cabling with no length limit) connects the controller, keypads, occupancy sensors, and light-level sensors. A gateway provides communication between the C-Bus network and two DALI networks, allowing full 0% to 100% dimming with DALI ballasts so that architectural dimming and daylight harvesting can be achieved.
Little Neck, N.Y.-based Leviton's daylight management system, called miniZ, combines occupancy sensing, daylight harvesting, and flexible lighting control functionality. The company's lighting management system for control of electronic ballast loads uses a proprietary switching circuitry, called Z-Max, which provides switching under full load conditions at zero crossing with true zero current — meaning no arcing at contacts.
Wireless control. To ease the task of setting up and using a lighting control system, a number of manufacturers are introducing wireless control products, which usually are an extension, or adjunct, to a wired system. Essentially, with this technology, it's possible to eliminate the low-voltage communication wiring to every lighting fixture if a wireless receiver is imbedded in the ballasts.
A typical wireless communications system uses “mesh” topology, meaning that numerous wireless nodes are interconnected. Because they are self configuring, the nodes are able to find the best path for signal transmission, going around blocking obstructions such as building steel.
An open-source mesh network technology, called ZigBee, is leading this effort in commercial, industrial, and institutional markets. ZigBee is the nickname for a short-range radio communications system (about 90 feet indoors) using battery-powered nodes. The system functions off a low data rate (up to 250kbits/s in the 2.4 GHz band) on a limited bandwidth for minimum power consumption in low-duty cycle applications such as control of lighting, temperature sensing, or security monitoring systems. When not transmitting, a node goes into a sleep mode drawing only a few microamps, so a battery can last for years.
Thus, ZigBee is a set of networking, security and application software that fits into the IEEE 802.15.4 low-data wireless standard and is managed by the ZigBee Alliance — a consortium of manufacturers.
For residential use, ZigBee along with similar standards (such as Z-Wave) provides new options for serving a variety of home automation applications. They have very limited bandwidth, and much greater range compared to Bluetooth, Wireless-USB and UWB, which makes them ideally suited for tasks involving remote control of lighting, sprinklers, and HVAC needs.
Philips Lighting, Somerset, N.J., has a ZigBee-compatible dimmable fluorescent ballast that incorporates wireless control for up to 65,000 nodes in a mesh configuration.
Designed for commercial and industrial applications, the LumaWatt Hi-Lo from Cooper Lighting, Peachtree City, Ga., is a wireless mesh-networked motion sensor and photosensor for control of lighting loads. The firm's Aspire line of wireless control products incorporates Z-wave wireless control technology to reduce interference.
Fluorescent lighting. As evidenced at the show, the trend in office lighting over the last few years is a decided shift to low profile, suspended, indirect fixtures. A variety of T8 lamps and ballasts can handle these applications, since in addition to the standard 32W version, reduced-wattage T8 lamps are available in 25W, 28W, and 30W models. They are intended to replace the old 34W T12 lamps in luminaire retrofits where a 32-W T8 model would provide too much light.
However today's high-efficiency linear fluorescent products are the “super” T8 lamps and the T5 lighting systems. A high-performance T8 system joins a high-lumen, extended-life “super” T8 lamp (at a premium price) with a reduced-power electronic ballast to achieve a 15% to 20% reduction in wattage compared to a standard T8 system.
A number of technology enhancements displayed at the show favor the use of the T5HO lamp in many places where T8 fixtures are usually specified. The T5HO units can be spaced on 12-foot to 15-foot centers whereas T8 fixtures are typically spaced at 8-foot to 10-foot centers. The T5 lamp has a ⅝-inch diameter compared to 1 inch for the T8. This smaller diameter provides better optical control and fixture efficiency along with a more shallow housing compared to a T8 unit. In addition to office and institutional use, the T5HO lamp works in high-bay applications traditionally limited to metal-halide systems.
Holophane, Newark, Ohio, showed a family of T5 luminaires that provide the best conditions for gaining the highest lumen output in a typical industrial application. The fixture uses three vertically stacked T5 or T5HO lamps and a reflector with a total reflectivity of 98% for maximum luminaire efficiency. The fixture uses a heat pipe technology developed by NASA to optimize the lumen output of these lamps where the ambient temperature around the lamps could rise to 70°C or higher. Liquid-filled tubes contact the metal ends of the lamps and draw off excessive heat, maintaining maximum light output at the lamp's optimum ambient temperature of 35°C (95°F). At 95°F, the T5HO lamp produces 5,000 initial lumens (85 lumens per watt) and 4,650 mean lumens (79 lumens per watt).
HID sources. With fewer high-pressure-sodium lamps observed at the booths, metal-halide lamps continue to hold center stage, achieving continuous improvement in performance. The greatest interest centers on the line of ceramic metal-halide lamps, now available from 20W to 400W. This source offers color uniformity and stability equal to fluorescent, while also having a relatively long life. In lower wattages, the lamp shapes include single-ended and PAR, and they can replace existing halogen PAR 38 lamps (up to 90W).
GE's 20W ceramic metal-halide MR16 lamp looks like one of the best new sources, being ideal for accent and downlighting applications. The thumbnail-sized 20W ceramic metal-halide was a standout at the show since it proved 1,625 initial lumens and a 12,000-hour-rated average life — all while lasting three times longer than a standard halogen lamp and using one-third the energy of a standard PAR38 75W lamp. It has a 83 CRI and apparent color temperature of 3000°K. Look for further performance improvements with a new generation lamp in a year or two.
Solid-state lighting. The vigorous growth in solid-state lighting using LEDs was evident at a variety of booths. There was less emphasis on the flashy, color-changing fixtures and more emphasis on products that will move LEDs to mainstream applications — “white” LEDs with high brightness and efficiency that can be applied with plug-and-play simplicity. For starters, lighting professionals want light-emitting diode (LED) products that can replace traditional, higher wattage PAR lamps in track and recessed downlighting applications.
Developments in materials and manufacturing methods are nudging high-brightness LEDs closer to being replacements for fluorescent and incandescent sources in some general lighting applications. Lacking mercury (a heavy metal), LEDs are attractive for complying with Title 22 California Household Hazardous Waste Disposal laws, which regulate homeowner disposal of fluorescent lamps. Federal Reduction of Hazardous Substances (RoHS) regulations are also looming on the horizon.
The lamps are essentially tiny micro-chips encapsulated in resin that convert almost all of the electric power into a discrete color, with little IR or UV in the light beam. The lamp turns on in 60 nanoseconds, is vibration/shock resistant, lightweight, and offers low, or no, shock hazard. The light can be divided into multiple paths, distributed across a surface, or set in multiple planes.
Not quite ready for large-scale use, LEDs are now used in tight spaces, as steplighting, for directional/decorative/display use, architectural light source integration (such as coves and recesses), and numerous outdoor applications — including area and street lighting.
Operating at rated voltage, current and ambient temperature, useful life of an LED can range anywhere from 50,000 to 100,000 hours. To date, however, there are no standards on technical aspects of this source. This means that, in general, products at the show could not be compared with one another, and some manufacturer's claims regarding performance cannot be verified.
However, deficiencies of the LED source are continuously addressed in many manufacturers' research centers. For example, an ambient temperature higher than optimum leads to reduced light output and shortened life. All “white” LEDs have a color shift over time, and color mixing using various color LEDs in combination has problems since different materials degrade at different rates.
To answer these shortcomings, Herndon, Va.-based Renaissance Lighting's ED series of recessed downlights mixes and blends the output from a number of LED chips in an integrating chamber to produce 600 initial lumens of “white” light. A patented system continuously calculates the light output, and apparent color temperature and “sleeper” LEDs are activated in some LED arrays to automatically boost the light output, which can be maintained at six color temperatures between 2800°K and 5600°K.
This technique compensates for the shift in light output and color balance that occurs as the diodes degrade over time and at different rates relative to one another. Additionally, the output can be dimmed to 10% without any shift in color temperature. This method of dynamically improving color and output may lead to other technologies for improving acceptability of LEDs in a variety of applications.
Permlight, Tustin, Calif., offers a line of recessed downlights that can replace 65W to 75W incandescent and 26W compact fluorescent recessed can trims in residential and commercial applications. The fixture can be served by a standard line voltage dimmer and is classified for use with multiple insulation contact (IC) and airtight (AT) recessed cans in new and retrofit construction.
Two manufacturers (Philips Lumileds Lighting, San Jose, Calif., and Journee Lighting, Westlake Village, Calif.) have an accent lighting unit that looks like an MR-16 fixture, or track head. One of the units has a simple control for dimming and changing the power settings.
Boston-based Color Kinetics' patented DIMand technology allows LED lamps to interpret standard dimming control signals, so a standard wall box dimmer can be connected to the device. Other manufacturers have similar devices to operate LED lighting devices from occupancy sensors, photocells, and building automation systems.
Two manufacturers showed second-generation LED refrigerated display lighting arrays that can reduce energy consumption on a five-door, reach-in case by more than 40% when compared with T8 fluorescent lamps. The savings are even more favorable when compared with HO or VHO fluorescent lamps. The LEDs eliminate lamp breakage and offer reduced maintenance along with greater light-level uniformity across the face of products.
By the end of 2006, a Far East manufacturer plans to have a 350mA LED with an output of 98 lumens and an efficacy of 84 lumens per watt in cool white and 67 lumens per watt in warm white. Another has a new white-light device that achieves an efficacy of 100 lumens per watt.
Daylight harvesting. Skylighting, or daylighting, systems found their niche among the booths showing electric lighting products, thereby slowly introducing daylighting into the traditional design process. The typical market for a skylighting system is a warehouse or big box retail outlet, with a large expanse of flat roof, where minimum energy use during daylight hours is desired.
One skylighting system consists of a 4-foot-square by 4-foot-high unit containing an array of mirrors inside a clear dome. A motorized control box on the dome's top adjusts the array automatically every 10 minutes, tracking the sun's path across the sky. Small solar panels within the dome serve the motor, and a battery backup is available for cloudy days. The control box software adjusts for seasonal changes.
Lighting the way. As evidenced from observations straight from the show floor outlined above, Lightfair 2006 was not without innovation. Celebrating its 17th year as the lighting industry's premier North American trade show, the event was also the largest conference the organization has held to date. Attendees discovered more than 550 exhibitors, showcasing the latest products and services, technological advances, and design solutions.
The conference component also proved highly successful as Lightfair hosted its largest conference program in Las Vegas history with 237 hours of CEU-accredited courses, workshops, and seminars.
Lightfair 2007 will be held May 8-10 at the Jacob K. Javits Convention Center in New York.