Sometimes, the customer isn’t exactly sure what they want. Field-adjustable (also called field-selectable) lamps and luminaires reduce guesswork for electrical contractors by allowing lighting performance to be dialed in during installation, which improves service efficiency.
These lighting products are essentially staple LED lamps and luminaires that enable performance parameters to be simply adjusted in the field during installation. For indoor lighting, this is typically either light output or correlated color temperature (CCT) and light output, although some products also offer a selection of light distribution. For outdoor lighting, it typically involves light output, but it may also include other parameters such as CCT.
As a result, a field-adjustable LED troffer might be available with a choice of low (3,350), medium (3,850) and high (4,350) lumen output with an associated range of wattages and a choice of 3,500K, 4,000K and 5,000K CCTs. A floodlight might offer a choice of three lumen outputs from around 5,500 to 11,000 lumens, choice of CCT from 3,000K to 5,000K and an integral photocell field-selectable as on or off.
To learn more about this emerging trend, I talked to experts from lighting manufacturers Acuity Brands (Atlanta), Cooper Lighting Solutions (Houston) and RAB Lighting Inc. (Northvale, N.J.). They said the most common means of adjustment is a set of mechanical switches that are part of the driver or wired to it. By flipping these switches on the driver or housing, the contractor can select one of multiple, labeled, factory-preset light outputs/wattages, CCTs, etc. The switches control power to the LEDs to raise or lower light output in steps and manage power between warm and cool LED arrays to achieve the desired CCT.
Typically, they are set, installed and left alone, but it is possible to regain access to the product and reset it later by adjusting the switches on the driver or housing. For easier ongoing adjustment to accommodate space changes, some products are available with wireless control by a smartphone app or using a compatible lighting control system.
In the luminaire space, the trend started with stock downlights and lay-in troffers and panels. It grew to include undercabinet lights while encompassing CCT and lumen output, then expanded to industrial high bays and outdoor floodlights, wall packs, canopy luminaires and area lighting, where the primary selection factor is lumen output.
For the electrical contractor, whether to use these lamps and luminaires depends on the project. For precisely specified projects, the justification for the cost premium related to the added functionality and engineering diminishes because the designer, and presumably the owner, know exactly what lighting performance they want.
For other projects, the contractor can bring field-adjustable luminaires, and—as long as they have the right luminaire type—they gain a great deal of flexibility in working out the right light output and CCT with the customer at the job site with less back and forth, concerns about availability and chance of being called back. With these luminaires, contractors arrive at precision upon installation, not so much before. While a little more time may need to be spent with the customer during installation, service efficiency can increase by leaving a satisfied customer.
For a lighting upgrade in an existing building, this can be quite valuable, particularly if the application has plenty of variability, such as different space types or ceiling heights. A less-precise audit may be needed, as long as the contractor brings the right luminaire type in the right quantity, as light output and CCT can be tuned as needed in the field.
The customer can control the lighting system’s performance by seeing options in the actual space. After installation, users can adjust the lighting system to accommodate space changes, either themselves or by calling their contractor.
Field-adjustable luminaires are typically permitted by lighting rebate programs offered by utilities and energy-efficiency organizations. Rebate fulfillment firm BriteSwitch reported the average rebate in 2021 was $33–$34 for a field-adjustable troffer/panel, retrofit kit or downlight; $120 for a high-bay luminaire; and $91–$97 for outdoor wall and pole/arm-mount luminaires. The DesignLights Consortium (DLC) allows field-adjustable luminaires in its Qualified Products List, which many rebate programs use to qualify LED products as being eligible for rebate.
There is some variability, however, in how rebate programs treat these products. Some recognize only the DLC-listed wattage, or the maximum wattage among the choice of light outputs, while others may recognize a lower wattage based on some type of verification. When installing field-adjustable luminaires in projects where a rebate will be sought, it would be beneficial to confirm if and how the rebate applies, install DLC-listed products if required and, if managing the rebate directly, file for preapproval.