Green Leaf Tempe Station, an apartment complex located near the Arizona State University campus in Tempe, Arizona, is home to college students and professionals. The 16-building, 400-unit complex on 18.5 acres offers roomy floor plans, a resort style pool and spa, grilling areas, a fitness center, a detached garage/storage building, a maintenance shop, and a mail kiosk. Units range from 854 to 1441 square feet and feature up to three bedrooms and two bathrooms.
Green Leaf Partners Company, a firm devoted to conservation and sustainability, recently acquired the property. For this reason, the company provides energy-efficient technology which can include: solar energy systems, energy efficient appliances, programmable thermostats, and LED lighting.
Complex Utilizes LED Lighting and Other Energy Saving Measures
David Burrill, corporate construction manager for Green Leaf Partners, said, “At all of our properties, Green Leaf Partners makes substantial improvements with goals of sustainable building, reduced waste and energy efficiency. Many times, the biggest impact and best benefit we could afford our residents and investors is in energy savings. The easiest and least expensive way to save energy is through the use of high-efficiency LED lighting.”
Green Leaf Partners asked Energy Efficiency Pros, a specialty LED lighting provider based in Tempe, to conduct an energy audit of the entire complex. The audit included looking at lighting for interior, exterior, and common areas. Also, as part of the energy audit, Energy Efficiency Pros identified products and solutions for high-volume lighting applications. The company worked with Ferrin Electric in Mesa, Arizona.
Energy Audit Results
The audit revealed that the property was utilizing 250- and 400-watt high-intensity discharge (HID) lamps; T8 and T12HO fluorescent lamps; 12-, 18-, 40-and 42-watt compact fluorescent lamps (CFLs); 40-watt incandescent lamps; 25-watt halogen; and 26-watt 4 pin fluorescents. Additionally, most of the plastic lenses on the wall mounted downlights over the building identification signs revealed discoloration from overheating/burning from the 100-watt incandescent bulbs.
The audit prompted management to convert the lighting to LED technology. Energy Efficiency Pros and Ferrin Electric decided to work with the property’s existing fixtures to produce the fastest payback using current LED technology. Also, Energy Efficiency Pros helped Green Leaf maximize the available incentives to reduce their costs for the LED retrofit project.
Energy Efficiency Pros Converts Property to LED Lighting
Don Bartelt, vice president of sales and operations for Energy Efficiency Pros, said, “The apartment complex was utilizing compact fluorescent lamps (CFLs) in its common areas and rooms, which were Energy Star rated but not really efficient. The CFLs had a six-month performance life at Green Leaf Tempe Station. Although CFLs are more efficient than incandescent bulbs, they do not come close to offering the benefits of LED lamps.”
Burrell added, “During the audit, we reviewed every aspect of lighting. We look at color temperature to ensure the right kind of light for specific areas. For example, we put warm white 2700K light in bedrooms to create a more conducive restful environment. For exterior halls and parking lots, we used a 4000K light to increase visibility and safety. We looked at where a person puts on their make-up to the light coming from the bottom of your microwave, which illuminates where food is prepared.”
Green on the Inside
For interior spaces, Energy Efficiency Pros specified A15, A19, A21, BR20 B11, and G25 LED EarthBulbs from EarthTronics, Muskegon, Michigan.
Moreover, Bartelt recommended replacing 18-, 40- and 42-watt CFLs with 6-, 9- and 11-watt A15, A19 and A21 omni-directional EarthBulb LEDs which provide 450, 810 and 1100 lumens respectively for more than a 50 percent energy savings. These 2700K color temperature LED bulbs come feature a multi-chipset LED and an advanced cooling system that enables a 15,000-hour performance life.
They chose the 5-watt G25 EarthBulb LED bulbs for the apartment bathrooms, which also feature the multi-chipset LED and 15,000-hour performance life.
For interior downlight applications, 2700K BR20s proved ideal for dimming, recessed lighting, track lighting, and display lighting applications. The BR20 LED is rated to last 25,000 hours, which is more than 10 times longer than the CFLs they replaced.
They specified 4.7-watt B11 candle style LED bulbs from EarthTronics for the interior decorative lamps and wall sconces. Like the BR20s, the 2700K, 315 lumen light source also have a 25,000-hour performance life.
Light Quality Also Important
“Just as important as the energy savings, the LEDs maintained the light levels and a warm, comfortable residential environment,” stated Bartelt. “We recommended the EarthTronics LED products because of their proven, long-lasting quality and efficiency.”
In the fitness area, 8-watt Hylite LED lamps in the cans replaced 26-watt 4-pin fluorescents, for a 70% reduction in energy consumption. In the breezeway cans, the 45-watt CFLs were replaced by 10-watt Hylite LED VL, reducing energy use by 78 percent. These Hylite LED lamps will operate up to 50,000 hours, which also reduces maintenance costs.
Energy Efficiency Pros specified Westgate recessed downlights to replace the lighting in the Community Center and the floodlights around the complex. These downlights deliver 90 CRI and boast a rated lifetime of more than 35,000.
Green on the Outside
Outside, Energy Efficiency Pros specified the 150-watt Matrix iGLO LED Matrix Shoebox pole lamp to replace the 458-watt high-pressure sodium (HPS) lamps, reducing energy consumption by 67 percent while maintaining lumen levels. The easy-to-install IP65-rated lamp provides a soft yellow light without flickering or humming. Energy Efficiency Pros also replaced the existing 189-watt HPS pole lights with the 60-watt iGLO LED Matrix Floodlight for a 68 percent reduction in energy consumption. Both the 150- and 60-watt pole lamps feature a five-year warranty.
Westgate LED flood lamps were specified for pathway lighting and around the parking lots. Rated for 70,000 hours, the IP65-rated 15-watt lamps provide 1100 lumens. Their solid-state lighting technology requires no maintenance and provides high efficiency.
In the carports, Hylite™ 10-watt LED VL Lamps deliver illumination at 120° beam angles to replace 18-, 26- and 32-watt CFL lamps. The LED lamps also have a rated lifetime of up to 50,000 hours, which further reduces maintenance costs. In addition, the two-per-fixture, 34-watt T12 fluorescent lamps, were replaced by LED 15-watt T8 lamps, saving more than 50 percent.
Project Completed in April
The extensive lighting project which began in January was completed by April to deliver immediate and substantial savings for the property.
Bartelt concluded, “After LEDs were installed, Green Leaf Partners was very pleased with the energy reduction and the quality of light, which provides comfort to its residents and meets the property’s environmentally friendly mission. Overall, Green Leaf Tempe Station will reduce its lighting energy consumption by more than 400,000 kWh each year. Green Leaf Tempe Station truly sets the bar for green living.”