Craig DiLouie, LC, CLCP recently interviewed Ethan Biery, LED Engineering Leader, Lutron Electronics about TLED retrofits and control options.
DiLouie: What basic choices do building owners have to upgrade existing troffer-based fluorescent lighting systems to LED?
Biery: There are three basic choices for TLED retrofits:
1. UL Type A: TLEDs retrofitted with existing fluorescent ballasts
2. UL Type B: TLEDs wired directly to line voltage (LED driver is internal to the lamp)
3. UL Type C: TLEDs supplied with dedicated LED drivers (LED driver is external to the lamp, and replaces the ballast)
DiLouie: What are typical energy savings and other advantages of replacing fluorescent troffers with LED troffers/panels?
Biery: Energy savings varies widely depending on the fixtures you select, as well as the fixture being replaced. Often, LED troffers put out fewer lumens, or make better use of lumens, to achieve their energy savings. It’s always a good idea, when you are considering for any lighting retrofit, to make sure that you are also taking the opportunity to include controls as part of the retrofit. Controls can significantly increase the flexibility and comfort of space lighting, and in all cases, control will increase energy savings.
DiLouie: What are the disadvantages of replacing the troffer with an LED luminaire compared to TLED lamps and retrofit kits?
Biery: The primary challenge of any LED Retrofit is ensuring compatibility among controls, fixtures and lamps. LED luminaire retrofits are generally the most expensive in terms of material and labor, but can often provide the best overall outcome.
DiLouie: What are conditions under which replacing the luminaire would be ideal as opposed to replacing the lamps?
Biery: To maximize energy savings, light quality, and controllability, and to ensure the best results in the future, replacing the existing fluorescent luminaire with an LED fixture, driver, and a fully-tested, guaranteed compatible control system is the ideal approach.
DiLouie: How would you categorize TLED lamps and retrofit kits aimed at replacing fluorescent lamps in fluorescent troffers?
Biery: In general, a TLED retrofit is designed to deliver more energy-efficient lighting, with potentially a longer life. But it’s important to consider that the ideal replacement product will not only deliver the desired energy and/or maintenance savings, but will also guarantee maintaining or, preferably improving, lighting quality in the space.
DiLouie: What are typical energy savings and other advantages of replacing fluorescent lamps with TLED lamps and retrofit kits? What are the disadvantages of replacing the lamps in a fluorescent troffer with TLED lamps instead of replacing the luminaire?
Biery: Energy savings will vary widely based on the type of fixture being replaced, the type of replacement being done (fixture vs. lamp, for example), and the exact product being used. For example, replacing inefficient T12 lamps with ANY LED solution will show significant energy savings. Replacing much more efficient T5 lamps are likely to show trivial energy savings.
The most important element is choosing an appropriate retrofit option. Improper installation, lamps and controls that have not been tested together, and low-cost, simple solutions will often reduce occupant comfort, decrease light quality, and may even affect ballast life such that the retrofit will not last any longer than the existing lighting system would have lasted.
Because the greatest cost in any building is the cost of the people in the space (and NOT the energy used), poor light quality that results in an uncomfortable environment is a huge, and very costly, disadvantage.
DiLouie: What are conditions under which replacing the lamps with TLED lamps instead of replacing the luminaire would be ideal?
Biery: TLED retrofits are ideal in an application that only requires switching, will never require control, and in which light quality is not critical to the tasks in the space. In this case, there is minimal concern for compatibility or light quality, and the entire focus can be on a strict energy-based ROI.
DiLouie: What control options exist for TLED lamps and retrofit kits?
Biery: All control options available for LED lighting are available for TLED retrofits (0-10V control, Lutron EcoSystem control, and even wireless control). No matter which option is chosen, the same concerns with control of all LED fixtures applies: ensuring compatibility and good dimming performance with any control system being used. Poor performance can result if you choose a seemingly quick, lowest-cost TLED lamp retrofit.
DiLouie: If you could tell the electrical industry just one thing about retrofitting fluorescent troffers to LED, what would it be?
Biery: I’d say they should never use a Type A TLED retrofit with existing fluorescent (dimming) ballasts if a control system is in place, or is ever going to be desired. If you are performing a TLED retrofit to maximize energy savings or performance, Type A is not a good option. Our experience has shown Type A lamps to not perform nearly as well as fluorescent lamps when it comes to dimming performance on existing dimming fluorescent ballasts.
DiLouie: Is there anything else you’d like to add about this topic?
Biery: As with any lighting control retrofit, keep in mind the 3/30/300 rule. In general, a building pays $3/square ft for energy costs, $30/square ft for operations cost, and $300/square ft in employee expense. Any lighting and controls retrofit should help reduce costs in all three areas by saving energy, reducing maintenance cost, and increasing employee productivity, and should not favor saving in one area (energy) but adversely affecting another (employee comfort/productivity).