The retrofit decision most people skip: which conversion path to take
There is not one way to convert fluorescent fixtures to LED. There are four, and they produce different results in efficiency, reliability, labor cost, and rebate eligibility. Choosing the wrong path does not just leave money on the table. It can saddle the building with a fixture that fails when the old ballast dies, or trigger an energy code compliance requirement that was not in the original scope. This guide covers the four paths, the tradeoffs of each, and the cost math that tells you which one fits.
The four retrofit paths compared
| Method | What changes | Installation labor | Efficiency | Long-term reliability | DLC / rebate eligible? |
|---|---|---|---|---|---|
| Type A: Plug-and-play LED tube | Lamps only. Existing ballast stays. | Lowest. Swap tubes, no wiring. Anyone can do it. | Good, but ballast draws parasitic power (3-8W per fixture). Net efficiency lower than Type B. | Weakest. When the ballast fails, the LED tube goes dark too. Ballast becomes the single point of failure. | Rarely. Most plug-and-play tubes are not DLC listed because the system (tube + ballast) is not tested together. |
| Type B: Ballast bypass (direct wire) | Remove ballast. Wire line voltage directly to sockets. Replace lamps with direct-wire LED tubes. | Higher. Requires electrician. Must verify tombstone type (shunted vs. non-shunted). May need tombstone replacement for single-ended tubes. | Best for tubes. No ballast power draw. Full wattage reduction. | Strong. No ballast to fail. LED tube and driver are the only components. | Some tubes are DLC listed individually. Check the DLC QPL for the specific product. |
| Type AB: Hybrid tube | Works with existing ballast now. Can be direct-wired later if ballast fails. | Low initially (plug-and-play). Higher later if rewired after ballast failure. | Same as Type A while running on ballast. Same as Type B after bypass. | Good. Future-proofed. Ballast failure does not require a new tube, just a rewire. | Varies by product. Check QPL. |
| Retrofit kit (LED light engine + driver) | Remove lamps, ballast, reflector, and often tombstones. Install new LED module and driver into the existing housing. | Highest. Full internal teardown and rebuild. Requires electrician. | Best overall. Integrated optical design (up to 160 lm/W). No legacy components drawing power. | Strongest. Complete new lighting system inside the old shell. Only the housing is reused. | Most likely. Retrofit kits are the most commonly DLC-listed option because they are tested as complete systems. |
Source: Industry classification follows UL Type A (plug-and-play), Type B (ballast bypass), and Type AB (hybrid) designations. DLC listing status varies by manufacturer and specific product. Always verify on the DLC QPL (designlights.org/qpl) before specifying for a rebate project.
There is a fifth option: full fixture replacement. If the existing fixtures are physically damaged, rusted, or in a poor location, none of the retrofit paths make sense. Removing the old fixture and installing a new LED troffer or panel is cleaner, faster (no teardown), and delivers the best optical performance. The tradeoff is higher material cost and the need to patch or accommodate changes in the ceiling grid. For fixture recommendations, see the Jarvis troffer and panel collection.
The ballast question: why it matters more than the tube
The ballast is the most important component in this decision, and it is the one most people think about last. Here is why:
Every fluorescent fixture has a ballast that regulates the electrical current to the lamps. In T12 fixtures, these are magnetic ballasts (heavy, humming, inefficient). In T8 fixtures, they are electronic ballasts (lighter, quieter, more efficient). Both types have a finite lifespan, typically 40,000-60,000 hours for electronic ballasts and less for magnetic.
If you choose a Type A plug-and-play LED tube, the LED tube runs on the existing ballast. The LED tube may last 50,000 hours, but if the ballast fails at hour 30,000, the entire fixture goes dark. You now need to either replace the ballast (to keep using Type A tubes) or rewire for ballast bypass (making the original Type A choice a wasted investment in labor and product). This is why Type A is the cheapest upfront but often the most expensive over 10 years.
Check the age of the ballasts before choosing a path. If the fluorescent fixtures are more than 10 years old, the ballasts are approaching the end of their useful life. Investing in Type A tubes for a ballast that may fail in 2-3 years is not a savings, it is a delayed expense. For older fixtures, Type B (ballast bypass), retrofit kit, or full replacement are the paths that make financial sense.
Tombstones: the detail that trips up ballast bypass installations
Tombstones (lamp holders / sockets) come in two types: shunted and non-shunted. The type matters for ballast bypass (Type B) installations.
Shunted tombstones have the two electrical contacts internally connected. They work fine for fluorescent lamps and for double-ended Type B LED tubes. They do NOT work for single-ended Type B LED tubes, which need separate power and neutral connections at one end.
Non-shunted tombstones have independent contacts. They work for all tube types: fluorescent, Type A, Type B (single or double-ended), and Type AB.
If you are doing a ballast bypass with single-ended tubes and the fixture has shunted tombstones, you must replace the tombstones on the powered end. This adds material cost (tombstones are inexpensive) and labor time (a few minutes per fixture). Double-ended Type B tubes avoid this issue because they work with either tombstone type. This is one reason many electricians prefer double-ended bypass tubes.
The code trigger most retrofits miss
ASHRAE 90.1-2022 Section 9.1.1.3 sets a threshold: if the total wattage of the lighting being altered exceeds 2,000W, the altered lighting must comply with LPD limits AND control requirements. A building with just 17 four-lamp T8 troffers at 120W each exceeds the 2,000W trigger (17 x 120W = 2,040W).
This means most commercial fluorescent-to-LED retrofit projects must meet the current energy code, not just swap the light source. If the building did not previously have occupancy sensors, daylight-responsive controls, or scheduling, the retrofit scope must include them. This is where retrofit budgets go off the rails: the fixture swap was quoted, but the controls requirement was not discovered until the inspector showed up.
For the full breakdown of ASHRAE 90.1 lighting requirements, see the energy code guide. For the controls strategies that satisfy the code and qualify for additional rebates, see the lighting controls guide.
Worked example: 200-troffer office building
The project
Given: A 40,000 sq ft office building with 200 recessed 2x4 troffers. Each troffer has 3 T8 fluorescent lamps and an electronic ballast drawing 88W total per fixture. Fixtures are 12 years old. Operating 3,000 hours per year. Electricity rate: $0.11/kWh.
17.6 kW x 3,000 hrs = 52,800 kWh/year
52,800 x $0.11 = $5,808/year in lighting energy
Option 1: Type A plug-and-play LED tubes
Ballast draw (retained): ~6W
Total per fixture: ~42W
200 x 42W = 8,400W -> 8.4 kW x 3,000 hrs = 25,200 kWh
Annual cost: $2,772 | Savings: $3,036/yr (52%)
Material: ~$8/tube x 600 tubes = $4,800
Labor: minimal (lamp swap) ~$2,000
Total project cost: ~$6,800 | Payback: 2.2 years
Risk: Ballasts are 12 years old. Failure = dark fixtures.
Option 2: Type B ballast bypass LED tubes
200 x 36W = 7,200W -> 7.2 kW x 3,000 hrs = 21,600 kWh
Annual cost: $2,376 | Savings: $3,432/yr (59%)
Material: ~$8/tube x 600 + tombstones where needed = $5,400
Labor: electrician, ~30 min/fixture = $10,000-15,000
Total project cost: ~$16,000 | Payback: 4.7 years
Reliability: No ballast to fail. Longest-lasting tube option.
Option 3: Retrofit kit (LED light engine + driver)
200 x 30W = 6,000W -> 6.0 kW x 3,000 hrs = 18,000 kWh
Annual cost: $1,980 | Savings: $3,828/yr (66%)
Material: ~$35/kit x 200 = $7,000
Labor: electrician, ~25 min/fixture = $8,000-12,000
Total project cost: ~$17,000 | Payback: 4.4 years
Rebate: DLC-listed kits qualify. At $25/fixture: $5,000 rebate
Net project cost after rebate: ~$12,000 | Payback: 3.1 years
Summary
Annual savings: $3,036 $3,432 $3,828
Project cost: $6,800 $16,000 $17,000
Rebate potential: $0 Varies $5,000
Net cost: $6,800 $16,000 $12,000
Payback: 2.2 yrs 4.7 yrs 3.1 yrs
Ballast risk: HIGH None None
10-year savings: $30,360 $34,320 $38,280
Values are estimates for illustration. Actual tube, kit, and labor costs vary by region and supplier. Rebate amounts vary by utility program. Always verify DLC listing and rebate eligibility before specifying. For the correct lumen method calculation to verify the replacement provides adequate foot-candles, see the lumens guide.
Frequently asked questions
How much energy does switching from fluorescent to LED save?
LED replacements are 18-44% more efficient than T8 fluorescent lamps, per a University of Michigan lifecycle study. In practice, typical fluorescent troffers draw 88-120W. LED equivalents draw 30-42W depending on the retrofit method. That is a 50-65% wattage reduction per fixture. For a 200-troffer building at 3,000 hours/year, annual savings range from $3,000 to $3,800 depending on the path chosen.
What is the difference between Type A, Type B, and Type AB tubes?
Type A (plug-and-play) works on the existing fluorescent ballast. No rewiring. Type B (ballast bypass) requires removing the ballast and wiring line voltage to the sockets. Type AB (hybrid) works either way: on the ballast now, or direct-wired later if the ballast fails. Type A is cheapest to install but has the weakest long-term reliability because the ballast becomes the single point of failure.
LED tubes or retrofit kit?
Retrofit kits replace everything inside the fixture housing with a purpose-built LED light engine and driver. They deliver higher efficacy (up to 160 lm/W vs. ~120 lm/W for tubes), better optical control, and are more commonly DLC listed for rebates. Tubes are cheaper per fixture but leave legacy components in the circuit. For projects where rebate eligibility and maximum long-term savings matter, retrofit kits are the stronger choice. Browse Jarvis retrofit kits here.
Does the retrofit trigger ASHRAE 90.1?
If the total wattage being altered exceeds 2,000W, yes. That is just 17 troffers at 120W each. The altered lighting must meet LPD limits or achieve 50% wattage reduction, AND comply with mandatory controls. Most LED retrofits easily hit the wattage reduction, but the controls requirement (occupancy sensors, scheduling) often adds scope and cost. See the energy code guide.
Do I need to replace the tombstones?
Only for single-ended Type B (ballast bypass) tubes in fixtures with shunted tombstones. Double-ended Type B tubes work with either shunted or non-shunted tombstones. If you are unsure, check the LED tube manufacturer's wiring diagram. When in doubt, use double-ended bypass tubes to avoid the tombstone variable entirely.
What about mercury disposal?
Fluorescent lamps contain mercury and are classified as universal waste under EPA regulations. They cannot be thrown in regular trash. Most electrical distributors and waste haulers accept fluorescent lamps for recycling. Many states have specific disposal requirements. Document the disposal for the building owner's environmental compliance records.
