Maximizing energy efficiency with advanced LED solutions and lighting controls in commercial spaces

Maximizing energy efficiency with advanced LED solutions and lighting controls in commercial spaces

It’s an LED world now; traditional sources are just living in it. The next frontier of energy savings lies in bringing the lighting controls revolution to mainstream adoption in existing buildings via best practices.

When upgrading a fluorescent luminaire—once the workhorse of commercial lighting—to LED, there are three options: replace the lamps with TLED lamps, adapt the luminaire with a retrofit kit, or replace it with a purpose-built LED luminaire (which may entail a lighting system redesign). For all three options, energy savings can be maximized by incorporating staple lighting control strategies to take advantage of LED’s inherent controllability.

Decision Flowchart for Retrofitting Linear LED Lighting | Source: U.S. General Services Administration

These options are addressed in detail in LED Lighting and Controls Guidance for Federal Buildings, a December 2023 publication by the General Services Administration (GSA) in concert with the Department of Energy (DOE) and the Pacific Northwest National Laboratory (PNNL). While aimed at providing a lighting upgrade road map for federal facility managers, its concise and clear guidance is widely applicable, particularly for office buildings and similarly lighted commercial buildings.

Lighting Decisions

Ideally, any new lighting solution should match or improve lighting quality. While defining value this way often favors retrofit kits and new luminaires, the reality is market laggards are more likely to upgrade to the nearest equivalent at the lowest cost, which favors TLED replacement lamps and retrofit kits.

When replacing fluorescent fixtures with LED luminaires as part of a redesign/renovation, nearly anything is possible within the design limits of the existing construction—from lighting to controls to power options such as power over Ethernet (PoE). If the existing lighting system is old and/or in poor condition; if maximizing energy savings is a priority, possibly as part of a decarbonization strategy; and/or if the ceiling/space will be altered, then new luminaires paired with an advanced lighting control system may be optimal.

If fixture replacement is impractical, the troffer retrofit kit is the next best option. These kits are composed of LED modules and optical and electrical components in a prepackaged, repeatable solution. Installation may require replacement of the ballast with an LED driver or may require bypassing the ballast via wiring the LED module directly to the branch circuit. The LED module may be compatible with existing lampholders or require new ones.

One advantage of retrofit kits is that the optics and heat sinking are engineered specifically for the LED light source to maintain or enhance lighting quality and optimize product life. The GSA recommends that if the lighting system will be in service for 5+ years with no anticipated changes to the ceiling of the space, a retrofit kit may be the right solution. Some kits are packaged with LED dimming drivers and integral sensors, maximizing both flexibility and energy savings by enabling cost-effective adoption of lighting controls.

At last, we come to the TLED lamp, which the GSA recommends considering if the existing luminaires are in good condition and are intended to be in use for some time. The three main types of TLED lamps are:

• UL Type A, which operates using the existing lamp ballast. Type A lamps are nominally low cost, though the cost of future ballast replacement must be accounted for. Disadvantages include the use of a ballast, which negatively impacts rated efficiency (and will eventually fail and must be replaced), and lack of utility rebates (as this is not a permanently installed solution).
• UL Type B, which features an internal driver, bypassing the ballast to connect directly to line voltage. These are the most popular TLED type, though one must address the attendant safety hazard to installing personnel, potential lighting quality issues, lack of dimming unless a control wire is connected to the luminaire, and widespread lack of rebates.
• UL Type C, which replaces the ballast with an external driver. As the lamp/driver combination is more purpose-built, lighting quality may be improved, including a lower likelihood of flicker. Additionally, numerous advanced control options, including wireless, become available with the use of Type C lamps.