Complete Guide to Replacing Fluorescent Lights with LED: Steps, Equivalents and Real Savings

Do you want to replace fluorescent lights with LED and don't know where to start. The process does not always require an electrician. Here are the equivalents, the installation methods and the real savings after the switch.

Why now is the time to switch fluorescent lights to LED

Fluorescent tubes have been used for decades in workshops, offices and kitchens, but their time is coming to an end. LED lighting systems provide greater energy efficiency and better light quality. European regulations phasing out fluorescent lights are reducing the supply of replacement T8 and T5 tubes every year.

The European regulation that is eliminating fluorescent lights

The European Union prohibits the manufacture and sale of fluorescent tubes due to their mercury vapour content, a substance that is hazardous to health and the environment. This elimination of mercury from fluorescent lights is part of the RoHS directive on luminaire waste. Finding replacements for this type of tube will become increasingly difficult. Switching now avoids running out of supply.

Common fluorescent light problems that LED solves

Stroboscopic flickering in fluorescent lights appears when the ballast ages. There is also the difference in cold start temperature between LED and fluorescent, with the latter taking time to reach full brightness when cold. LED lamps start at full power from the very first second. They maintain a constant light quality, without the progressive loss of luminous flux seen in older tubes.

Types of fluorescent light and their LED equivalent

Each family of fluorescent light has its LED replica.

A 36W T8 tube is equivalent to a 20W LED tube

The most searched-for fluorescent-to-LED power equivalence is that of the T8 tube. A 36W T8 fluorescent tube is replaced by an 18 to 20W LED tube without losing emitted light. The reason is simple: it converts more electric current into useful light and less into heat. Same lighting with less electricity consumption.

T5 tube replacement and adapters

T8 to T5 LED replacement follows a different logic because the T5 measures 16 millimetres compared to the T8's 26. There are specific LED T5 tubes for the same batten, although it is often best to replace the entire luminaire if it is already old.

Circular and compact fluorescent equivalents

Circular fluorescent LED replacement is solved with LED panels or rings of that format. For compact fluorescents there are LED bulbs with the same cap as the traditional incandescent bulb, a direct swap without touching the rest of the installation.

Replacement options depending on your installation

The right option depends on the ballast and the available budget.

Direct replacement with ballast bypass

Ballast bypass LED tube installation is the most economical option for replacing a fluorescent tube with LED without an electrician. It involves disconnecting the ballast and starter, and connecting the LED tube to the alternating current. Recommended when the ballast is already failing.

Complete luminaire replacement with an LED batten

Replacing a fluorescent luminaire with LED with a new batten is the cleanest option for starting from scratch. Current battens include their own power supplies, better power factor for LED luminaires and high-quality certification. Ideal when the original fluorescent-compatible LED diffuser is damaged or for a mass replacement of fluorescent lights in an office.

Compatibility with existing electronic ballast

Not all LED tubes work the same way with an electronic ballast. There is limited magnetic/electronic ballast compatibility depending on the model. Some tubes work with an electronic ballast without removing it, others require the bypass. A common doubt among those looking into how to switch from fluorescent to LED.

Step-by-step installation of the LED T8 tube

This is the most common step-by-step fluorescent-to-LED tube replacement without professional help.

Tools needed

A screwdriver, a voltage tester, insulating tape and the chosen fluorescent-to-LED replacement kit are enough. Always cut the power from the electrical panel.

How to safely perform the bypass

1. Disconnect the power and check that there is no voltage.
2. Remove the fluorescent tube and the starter.
3. Locate the ballast wires to the caps and disconnect them.
4. Connect live and neutral to one end of the LED tube, according to its label.
5. Insulate the connections with insulating tape.
6. Fit the LED tube and check that it is properly seated.

Testing and verifying the result

Restore the power and switch it on. The tube should light up immediately, without flickering, due to the instant start of LED versus fluorescent characteristic of this technology. If it does not light up, check the live and neutral polarity.

How much you save with the switch

The savings from switching fluorescent to LED are noticeable from the first bill. As an illustrative example, an office with 20 36W fluorescent lights switched on for 10 hours a day consumes considerably more energy. Compare this with the same number of 18W LED tubes over the same hours. The difference in fluorescent versus LED consumption translates into lower monthly energy consumption.

The comparative lifespan in hours of use of LED also exceeds that of the traditional tube. In the long run, electricity costs go down, with good accumulated energy savings.

What to do with used fluorescent lights

Removed tubes should not be thrown out with ordinary rubbish because they contain mercury vapour. Take them to a recycling centre or authorised waste manager, where recycling at a designated recycling centre for fluorescent lights guarantees safe treatment.

If you are looking for glass T8 tubes or weatherproof diffusers and battens, check out the Ibérica de Iluminación catalogue. You will find lighting solutions with good colour rendering CRI for LED tubes, colour temperature suited to each space and manufacturer's guarantee.

Frequently asked questions

Can I replace a fluorescent light with LED without changing the fitting?

Yes, in most cases. With the ballast bypass, the LED tube reuses the same housing and the same caps. The fitting only needs to be changed if it is damaged.

Which LED is equivalent to a 36W fluorescent light?

An 18 to 20W LED tube offers the same light as a 36W T8 fluorescent. The reduction in power does not affect the lighting because the LED makes better use of the energy.

Is it safe to do the ballast bypass myself?

Yes, as long as you cut the power before handling any wire and follow the manufacturer's diagram.

How much do I save per month if I switch 20 fluorescent lights to LED?

It depends on the hours of use and the price of electricity. As an illustrative example, 20 18W LED tubes compared to 20 36W fluorescent lights with 10 hours of daily use could mean savings of close to 50%.

What do I do with old fluorescent lights when I remove them?

Take them to a recycling centre or authorised waste manager, never to household rubbish. They contain mercury and must be treated as special waste.

Do LED tubes work with an electronic ballast without a bypass?

Some models do, if the ballast is compatible according to the technical data sheet. Others require it to be removed.

When is it better to replace the entire luminaire instead of just the tube?

When the diffuser is damaged, the ballast fails frequently or it is a large-scale renovation. If you are wondering when to fully switch fluorescent lights to LED, a new batten avoids future breakdowns and improves performance.