Fluorescent Tube Buying Guide

The fluorescent tube, also referred to as the fluorescent strip or tube light, is a low-pressure mercury vapour gas-discharge tube that converts fluorescence into visible light. This process involves the triggering of mercury vapour via an electric charge, resulting in the appearance of a short-wave ultraviolet light. This then causes the phosphor coating inside the tube to glow.

Fluorescent tubes have the advantage of benefitting from much greater energy efficiency than incandescent lamps. They are a relatively inexpensive form of lighting and have a relatively long life (although not as long as LEDs). Fluorescent tubes are used for a wide range of domestic and commercial applications.

Additional reasons for the use of fluorescent tubes include:

• High levels of light distribution and even diffusion
• Relatively low running costs
• Production of various colours, including white, red, and blue

Advantages of Using Fluorescent Tubes

Fluorescent tubes offer several advantages that make them a preferred choice for lighting in various settings:

• Their energy efficiency is significantly higher compared to traditional incandescent bulbs, reducing overall energy costs.
• They have a longer lifespan, which minimises the need for frequent replacements.
• Fluorescent tubes distribute light more evenly across spaces, providing uniform lighting that covers larger areas effectively.
• They are available in a range of colour temperatures, allowing for flexibility in creating desired atmospheres or meeting specific lighting requirements.
• Their low heat emission makes them safer for prolonged use, especially in confined or sensitive environments.

Fluorescent Tube Light vs LED

In the comparison of fluorescent tube light vs LED, several key differences should be noted regarding their differing energy efficiency, lifespan, environmental impact and cost-effectiveness. Fluorescent tubes operate by exciting mercury vapour, which in turn emits ultraviolet light that causes a phosphor coating inside the tube to glow. On the other hand, LEDs use semiconductor materials to convert electricity directly into light through the movement of electrons, making them more energy-efficient and environmentally friendly due to the absence of mercury.

Fluorescent tubes and lamps are available in a variety of shapes and sizes. The compact fluorescent lamp has gained considerable popularity in recent times, and it is widely adopted in Hong Kong, as evidenced by the Hong Kong Government’s various waste reduction and recycling programmes for the tubes. It is quite common for the auxiliary electronics to be integrated within the base of the lamp, allowing for compatibility with the common light bulb socket.

Fluorescent tubing may be installed for lighting the following places:

• Residential rooms
• Storage areas
• Commercial office spaces
• Parking garages
• Retail stores

Fluorescent Tube Choices by Wattage

The number of watts will be indicated after the F on the fluorescent tube. As an example, an F8 tube with 24 watts will have the number F24T8. The level of light output will also have a bearing on the wattage of the fluorescent tube. The efficacy of the fluorescent tube will range from around 16 lumens per watt for a 4-watt tube with a regular ballast to more than 100 lumens per watt for a tube featuring a modern electronic ballast. The level of light emitted from the fluorescent tube is also affected by the lamp temperature in the coldest area of the lamp.

Fluorescent Tube Choices by Size

Fluorescent tubes are measured in eighths of an inch, with the measurement being drawn from pin to pin at the end of the tube. The wattage level is dependent on the length of the fluorescent tube. The sizes of fluorescent tubing range from T2 to T17. Production of the largest size T12 (38mm) has ceased. However, they featured the same G13 cap as the T8 tube. This means that it is possible to replace the T12 tube with a more efficient T8 of the same length.

The comparative sizes of fluorescent tubes are highlighted in this table:

There is such a wide selection of fluorescent tubing available that it may be a challenge to identify the type best suited to your needs. However, factors such as the type of socket, diameter, wattage, length, colour coding, and ballasting should all have a bearing on your buying decision, as should the following:

Type of Fluorescent Tube

As previously mentioned, fluorescent tubes range from the modern T2 to the old style T12. The slim-line T2 tubes feature a W4.3 fitting and a 4.3 mm wide push fitting. T4 tubes are best suited to under-cabinet lighting and have a G5 fitting with 5mm separating the two pins. Standard T8 tubes have a G13 fitting, with 13mm separating the pins. The T12 tubes came complete with the same G13 cap as the T8 tube, meaning that older T12 tubes can be replaced with T8 tubes.

Wattage of Fluorescent Tube

You should be aware that lumens are specific to the total amount of light emitted by the light source, while watts refer to the amount of energy consumed. As the levels of energy efficiency increase, the wattage decreases in relation to the generation of lumens.

The following table indicates the number of lumens that are generated at different wattages:

Length of Fluorescent Tube

As previously stated, you can establish the length of a fluorescent tube by measuring the total distance between the two end pins. The wattage commonly indicates the lengths of these tubes. The smallest fluorescent tube is the T2, and it has a length of between 250mm and 760mm. The next longest tube is the T4, with a total length of anywhere between 150mm and 1,500mm. This is followed by the T5, which has a length of between 340mm and 1,800mm. The length of the T8 tube may be anywhere from 600mm up to 2,400mm.

Considerable care should be taken during the fitting of a fluorescent tube. Begin by turning off the power connected to the fitting. Any contact with the fitting and earthed elements should be avoided. It will be necessary to begin with the removal of the casing, which can then be placed in a safe and secure area. The tube should be gently twisted 90 degrees to release it from the light fitting. The attachment of the new fluorescent tube should begin with the placement of the short metal prongs in the corresponding holes. The new bulb should then be twisted gently through 90 degrees.

To ensure fluorescent tubes maintain their efficiency and longevity, regular maintenance is essential:

• Start by cleaning the tubes and fixtures periodically to prevent dust accumulation, which can impact light output and efficiency. Use a soft cloth to wipe the tubes gently, avoiding harsh cleaning agents that may damage the phosphor coating.
• Check the electrical connections and fixtures for signs of wear or damage, as poor connections can reduce the lifespan of the tubes. Replace starters and ballasts as needed since faulty components can cause flickering or prevent the tubes from lighting up.
• Rotate the tubes in their fixtures occasionally to promote even wear and extend their usable life.
• Consider implementing a scheduled replacement plan, replacing tubes in batches to maintain consistent light quality and reduce the risk of sudden failures.