Also consider longer-term solutions. Although these actions require more effort, they can dramatically increase the efficiency of your facility and can even improve the shopping environment at the same time. Ask your utility representative for more information about incentives for such projects.
Commissioning is the process of ensuring that systems are designed, installed, functionally tested, and capable of being operated and maintained according to the owner’s operational needs. Commissioning can cut energy bills by 10 to 15 percent or more and often provides a simple payback of under one year. When this process is applied to an existing building that has not been commissioned before, it is called retrocommissioning. When it is applied to a building that has been commissioned before, it is called recommissioning. Recommissioning is recommended every three to five years to maintain top levels of building performance. In another type of commissioning—monitoring-based commissioning—monitoring equipment is left in place to allow for ongoing diagnostics and may provide additional benefits beyond traditional commissioning.
Insulation can be one of the most important factors in improving energy efficiency in a building. Insulation not only saves money by reducing heating and cooling loads, it’s also a key factor in achieving comfortable living and working spaces. The effectiveness of insulation greatly depends on proper installation. Get a quote from an insulation specialist to make sure insulation is properly installed.
Building Automation Systems
Building automation systems, sometimes called energy management systems, can save 5 to 15 percent of overall building energy consumption while also improving occupant comfort. Older or poorly maintained buildings can also benefit greatly from a building automation retrofit, sometimes achieving savings of over 30 percent.
Lighting is critical, both in creating an ambiance and in making the merchandise attractive to shoppers. High-quality lighting can reduce energy bills and drive sales.
Display lighting. Proper display lighting, such as track lighting, is critical for driving retail sales and preventing merchandise returns. Quartz halogen lamps are commonly used for accenting merchandise because they provide a bright, focused column of light with excellent color quality. More efficient alternatives include CFL, metal halide, and LED track or spot lights. Have a lighting consultant review your lighting layout to ensure that it provides the appropriate light levels, quality of light, color rendering, color uniformity, and energy efficiency.
LEDs. LEDs are well on their way toward becoming an effective option for a growing variety of applications, including incandescent replacement lamps, parking lots, commercial signage, task lighting, refrigerated cases, recessed downlighting, ambient lighting in offices, and many high-bay applications. Retail accent lighting is a growing area for LEDs because they provide the ability to vary color, create sparkle, and aim the light precisely. Despite the technological advances, successful application of LEDs still requires care in selecting products that will meet specific illumination needs, match manufacturer claims, and be compatible with any controls that are employed.
LEDs boast a life ranging from 25,000 hours to more than 100,000 hours, depending on the application. The competition ranges from 1,000 hours for incandescent lamps to as much as 70,000 hours for induction lighting. For conventional lamps, such as incandescent, fluorescent, or high-intensity discharge (HID) lamps, life is defined as the hours of operation after which half of a representative sample of lamps can be expected to fail. In contrast, LEDs don’t generally fail outright, rather, their output declines over time—so the industry generally defines LED life as the point at which the light output has declined to 70 percent of its original value.
Fluorescent lamps. If your facility uses T12 fluorescent lamps or commodity-grade T8 lamps, relamping with high-performance T8 lamps and electronic ballasts can reduce your lighting energy consumption by 35 percent or more. Adding specular reflectors, new lenses, and occupancy sensors or timers can double the savings. Paybacks of one to three years are common.
Big-box retail stores with high ceilings might consider going to a high-bay lighting system that uses T5 or T8 lamps to boost both lighting quality and efficiency. LED adoption for high-bay systems has been slower than for other applications, but market penetration is growing. These lamps are more energy-efficient, offer better light quality, and are easier to dim or control with occupancy sensors than the HID lights that are typically found in high-ceiling stores.
Smart lighting design in parking lots. Parking lots are often overlit—an average of 1 foot-candle of light or less is usually sufficient. The most common lamps used for outdoor lighting are HID sources (metal halide and high-pressure sodium lamps). In recent years, fluorescent lamps, CFLs, and induction lamps have also become viable sources for outdoor lighting, offering good color quality and better control options than HID sources. LEDs are also rapidly becoming a good choice because they can reduce light pollution while offering high efficiency and long life. LED costs are decreasing, and performance continues to improve. Dimming and occupancy-sensing controls can also save energy in parking lots.
Security lighting. Using occupancy sensors with outdoor security lighting can save energy and improve security.
Daylighting. Daylight from skylights and windows can improve the ambience of a store and reduce the need for electric lighting. According to the American Council for an Energy-Efficient Economy, some evidence even suggests that daylighting can also lead to increased sales (PDF). Dimming ballasts and daylighting controls can be used to reduce the amount of electric light used when daylight is present.
LED signage. LEDs used in exit signs, “open” signs, and other applications can cut energy costs and also reduce maintenance costs compared to incandescent, CFL, neon, and other options.
When only a few people are in a store, you can save energy by decreasing the amount of ventilation supplied by the HVAC system. A demand-controlled ventilation (DCV) system senses the level of carbon dioxide in the return airstream and uses it as an indicator of occupancy. DCV can save energy during peak cooling periods when many shoppers are at work and occupancy is low. In retail sales applications, DCV works best when a dedicated HVAC system serves the sales floor.
If your building has packaged RTUs, consider installing RTU controllers; this technology allows RTUs that currently run on single speeds in single zones to operate in variable-speed modes. Controllers can save 25 to 50 percent of total RTU energy consumption for single-zone cooling with a capacity of 5 tons or greater. Simple payback periods are typically one to five years, without incentives.
If the roof of your building needs recoating or painting, consider creating a “cool roof” by using white or another highly reflective color to minimize the amount of heat the building absorbs. This change can often reduce peak cooling demand by 15 to 20 percent. For a list of suitable reflective roof coating products, check out Energy Star Roof Products.
Advanced Window Glazing
Modern, specularly selective glazing makes it possible to maintain good visibility through windows while limiting the solar gain that can heat a store and fade clothing colors. If your store is in a warm climate, replacing clear glazing with more advanced glazing can be done with short paybacks and can increase comfort for shoppers. Specify new glazing carefully—you may need to seek a different solution for each facade. In some cases, applying specularly selective window films to existing windows may allow you to achieve similar benefits as new glazing, but at a lower cost.