LED Retrofit vs New Commercial Light Fixtures: How to Decide

Many Twin Cities offices, stores and apartment buildings still have fluorescent or older high-intensity discharge lighting. Replacing it with light-emitting diode (LED) lighting lowers energy use and reduces maintenance. The two main methods are retrofitting the existing fixtures with LED parts and installing new LED fixtures.

The better choice depends on the condition of the existing fixtures, the lighting quality required, the controls the code calls for and how much disruption the space can tolerate. This guide compares the options.

What is the difference between an LED retrofit and a new fixture?

A retrofit keeps the existing fixture housing and replaces the light source. This can be an LED lamp (a replacement tube or bulb) or a retrofit kit, which includes LED strips or a new driver installed inside the old housing. A new fixture replaces the entire unit, including the housing, lens, light source and driver (the LED equivalent of a ballast, which controls power to the light source).

Should you bypass the ballast or keep it?

A ballast is the device in a fluorescent fixture that starts and regulates the lamp. LED tube lamps are sold in several types, and the type must match the wiring.

• Ballast-compatible (plug-and-play) tubes work with the existing ballast. Installation is simple, but the ballast stays in the fixture and will eventually fail. The tube also only works with certain ballast models, so the lamp manufacturer's compatibility list must be checked.
• Ballast-bypass (direct-wire) tubes receive line voltage directly. An electrician removes or disconnects the ballast and rewires the sockets. The result avoids ballast failure, but the fixture must be relabeled to show it was altered, and each lamp must be installed in a socket designed for it.
• Hybrid tubes work either way, which can simplify stocking and later maintenance.

Bypass wiring changes the fixture's listing, so the work should be done by a licensed electrician following the lamp manufacturer's instructions. Wiring errors can put line voltage on sockets that were not designed for it.

When do new fixtures make more sense?

Choose new fixtures when the existing housings are damaged, rusted or discolored, when sockets and wiring are old, or when the layout will change. They also suit spaces where light quality matters, such as showrooms, restaurants and offices where the ceiling or furniture is being replaced. Cold garages, loading docks and exterior areas may need fixtures rated for damp or wet locations and low temperatures.

New fixtures are the usual choice during a tenant improvement or any project where the ceiling is open. Installing them when access is already available costs less in labor than reopening the ceiling later. Review the options for commercial lighting with the layout, ceiling type and use of the space in mind.

What lighting controls should be considered?

Controls lower energy use further because lights turn off or dim when they are not needed. Common controls include:

• Occupancy and vacancy sensors, which turn lights on or off according to whether people are present. They suit restrooms, storage rooms, private offices and stairwells.
• Daylighting controls, which dim fixtures near windows and skylights when daylight is available.
• Time-based controls, which switch lights on a schedule in open areas.
• Dimmers and tuning controls, which change brightness for different tasks.

Controls must be compatible with the LED source. Not every dimmer works with every LED driver, and flicker or noise is common when they are mismatched.

Does the energy code require lighting controls?

Minnesota's Commercial Energy Code is adopted in Minnesota Rules chapter 1323. It adopts ANSI/ASHRAE/IES Standard 90.1-2019 with Minnesota amendments and covers new buildings and the alteration, renovation and repair of commercial buildings. That standard includes lighting power limits and lighting control requirements, such as automatic shutoff and space controls.

How much of the standard applies depends on how much of the lighting system is altered. Replacing only lamps is treated differently than replacing fixtures or rewiring a space. Ask the electrician and the building department which provisions apply before the scope is set, so the controls are included in the price.

Are utility rebates available for commercial LED lighting?

Utility rebates for business lighting exist in Minnesota. In Xcel Energy's service area, the Center for Energy and Environment operates the One-Stop Efficiency Shop, which is sponsored by Xcel Energy. It offers lighting assessments and rebate help to eligible Xcel Energy commercial customers, and its page describes a peak demand limit of 400 kilowatts. Other utilities have their own programs.

Rebate rules change, and they can require steps such as an assessment or approval before purchase or qualifying products. Read the current program terms and confirm eligibility before ordering materials. Business owners can use their own electrician for the installation.

How is lighting work planned in occupied spaces?

Lighting upgrades in occupied offices, stores and apartment buildings should be planned around people who work or live there. Common area lighting and electrical work in hallways, stairwells and parking areas also affects safety, so some lights must stay on during construction.

• Work in sections, so only part of a floor or corridor is dark at one time.
• Schedule noisy or dusty work, such as ceiling work, after business hours.
• Keep exit signs and emergency lights working, or provide temporary lighting where they are disturbed.
• Notify tenants or staff before circuits are shut off.
• Dispose of old fluorescent lamps and ballasts according to local waste rules, since some contain mercury or other regulated materials.

What are the next steps for an LED upgrade?

Walk the space and list the fixture types, ceiling heights and conditions. Decide which fixtures can be retrofitted and which should be replaced, and note where controls are required. Check utility rebate terms before purchasing.

Prime Time Electric MN, LLC (Minnesota Electrical Contractor License #EA807704) installs commercial lighting and common area lighting for Twin Cities properties. To review a lighting upgrade, request a quote or call 612-445-2794.