An LED retrofit replaces fluorescent, metal halide or other older lighting with LED sources, either by swapping lamps, installing conversion kits in the existing fixtures, or replacing the fixtures entirely. Done well, it cuts lighting energy, reduces maintenance and improves light quality. Done badly, it can leave you with glare, flicker, poor light levels and equipment that no longer carries a valid certification.
Why retrofit
- Energy. LED fixtures usually produce the same light with less power than the fluorescent or high-intensity discharge equipment they replace. In buildings where lighting runs long hours, the savings are significant.
- Maintenance. LEDs last much longer than most older lamps, which matters most where fixtures are hard to reach, such as high warehouse ceilings, atriums and parking structures.
- Controls. LEDs dim and switch easily, which makes occupancy sensing and daylight dimming more practical.
- Supply. Fluorescent lamps and ballasts are becoming harder to buy as regulations and the market move away from them.
- Capacity. Lower lighting load can free up electrical capacity for other uses.
The main retrofit options
For linear fluorescent fixtures, the most common case in commercial buildings, there are four broad approaches. The difference between them is mostly in what happens to the power path inside the fixture.
Ballast-compatible tubes
Sometimes called plug-and-play. The LED tube works with the existing fluorescent ballast, so installation is just a lamp change. The drawback is that the old ballast remains: it still uses some power, and when it fails, the tube goes out and the ballast must be replaced anyway. Compatibility depends on the specific ballast, so check the tube manufacturer's compatibility list.
Ballast-bypass tubes
The ballast is removed and line voltage is wired directly to the lamp holders. This removes the ballast's losses and failure point, but it modifies the fixture. Lamp holders may need to be replaced, the fixture must be labelled to show it has been converted, and anyone relamping in future must use the right tube. Putting a fluorescent tube into a bypassed fixture is a hazard. The conversion must be done by a qualified electrician.
Retrofit kits
The fixture's internals are replaced with a kit containing a new LED driver and LED boards or a new door assembly, while the housing stays in the ceiling. Kits can give better light distribution than tubes and avoid ceiling work. In Canada, a fixture modified with a kit must still be acceptable to the electrical inspection authority. The kit should be certified for the purpose by an accredited certification body, and installed according to its instructions. Uncertified kits or field modifications may need special inspection, or may not be accepted at all.
New fixtures
Replacing the fixture gives the most control over light distribution, glare, appearance and controls, and resets the life of the whole fixture. It costs more and involves more disruption, but for spaces where the existing layout or optics are poor, it is often the best value.
Comparing the options
| Option | Disruption | Light quality | Main watch-out |
|---|---|---|---|
| Ballast-compatible tube | Lowest | Depends on the existing fixture | Old ballast remains and will fail |
| Ballast-bypass tube | Low | Depends on the existing fixture | Modified fixture must be labelled and relamped correctly |
| Retrofit kit | Moderate | Often better than tubes | Kit must be certified and installed to its instructions |
| New fixture | Highest | Best control over glare and distribution | Higher cost and ceiling work |
High bay and outdoor lighting
Metal halide and high-pressure sodium fixtures in warehouses, gyms, parking lots and building exteriors are often good retrofit candidates because they run long hours, take time to restart, and are expensive to reach. Options include screw-in LED lamps, which often require bypassing the ballast and must be suitable for the fixture's enclosure and heat, kits and full replacement. For outdoor lighting, also consider light trespass onto neighbouring properties, local bylaws and dark-sky goals.
Planning a retrofit
- Survey the existing lighting. Fixture types, quantities, wattages, operating hours, mounting heights, condition and existing controls, by area.
- Measure existing light levels in representative areas, and note complaints such as dark areas or glare.
- Decide on the approach for each area. Tubes, kits or new fixtures, based on condition, ceiling access, light quality needs and budget.
- Check the design. For anything beyond a like-for-like swap, a lighting calculation confirms light levels and uniformity. See lighting levels and good lighting design.
- Add controls. A retrofit is the cheapest time to add occupancy and daylight controls. Check whether the energy code or a utility incentive program requires them. See lighting controls.
- Install and verify. A licensed electrical contractor installs the work under permit where required. Afterwards, check light levels, controls and emergency lighting.
A typical case
A distribution warehouse has metal halide high bays that take several minutes to restart after a power blip, and staff complain about dim aisles where lamps have aged. The first proposal is to put screw-in LED lamps into the existing fixtures. A closer look shows that the fixtures are old, several reflectors are damaged, and the screw-in lamps would require bypassing the ballasts in fixtures that were not designed for them. The owner instead chooses new LED high bays with aisle-shaped optics that put light down the racking faces where pickers read labels, and adds occupancy sensors so aisles dim when empty. A lighting calculation confirms the levels before purchase. The result uses less power, restarts instantly, and gives better light on the racks than the original system did when it was new. The emergency lighting is checked at the same time, since some of the old high bays had been relied on for egress lighting during an outage.
Common problems after a retrofit
| Problem | Usual cause |
|---|---|
| Glare | Bright LED sources with poor diffusers, or tubes in fixtures designed for diffuse light |
| Flicker | Poor-quality drivers or incompatible dimmers |
| Uneven light | Tubes with a narrower beam than the original lamps |
| Mixed colours | Different products or colour temperatures in one space |
| Early failures | Heat in enclosed fixtures, or ballast failure on ballast-compatible tubes |
| Emergency lighting not working | Emergency ballasts or battery packs not replaced with LED-compatible equipment |
Check incentives before you buy. Utilities and governments in different provinces have offered lighting incentive programs at different times. They often have product and pre-approval requirements that must be met before work starts.
How ehZee can help
Our lighting design and controls service can survey your existing lighting, recommend the right retrofit approach for each area, check light levels and design controls, and coordinate the work with your electrical contractor.
Common questions
Are LED tubes safe to install myself?
Ballast-compatible tubes are a lamp change, though you must confirm compatibility. Ballast-bypass tubes and kits involve rewiring the fixture and must be installed by a qualified electrician, usually under permit.
Will an LED retrofit lower our light levels?
It can raise or lower them depending on the products. Choosing by lumen output and distribution, not by wattage, and checking with a calculation avoids surprises.
What happens to the old lamps?
Fluorescent and HID lamps contain mercury and should be recycled through a program that accepts them. Ballasts from older fixtures may need special handling. Check your provincial and municipal rules.