The initial cost of T8 lamps depends mainly on the performance characteristics discussed in the previous sections. For a summary of overall performance, see How can the overall performance of T8 fluorescent lamps be compared? In general, the least expensive 4-foot, 32-watt T8 lamps are RE70 (having CRI values in the 70s), have an average rated life of 20,000 hours, a lamp efficacy of less than 90 lumens per watt, and a 90-95% lumen maintenance. As expected, the cost per lamp generally increases as rated performance increases, with the most expensive lamps typically having better claimed performance in multiple categories. Lamp prices also vary dramatically among suppliers. Table 1 shows an example of how cost increases with better claimed performance and how widely costs can vary between suppliers for the same manufacturer’s lamp model. Suppliers A and B, which are nationwide distributors, supplied all lamp models listed.
|Table 1. T8 lamp pricing example for one lamp manufacturer|
|Lamp||Lamp efficacy (LPW)||Average rated life (hours)||Supplier||Price per lamp|
|RE80 HLO, LL||95||24,000||A|
Table 1 shows that the cost of a RE80 HLO, LL lamp from supplier A is 64% higher than a RE80 lamp from the same source ($5.46 versus $3.32). Since the cost of energy can be as high as 95% of the total cost of lighting, the higher lamp efficacy of the RE80 HLO, LL lamps may provide an opportunity to recoup this higher initial cost. However, the actual power of the RE80 HLO, LL lamps is higher than the actual power of the RE80 lamps (see What are the power requirements for T8 fluorescent lamps?). Therefore, a change in lighting layout or a change to a ballast with a lower ballast factor is essential in order to take advantage of the higher lamp efficacy of the RE80 HLO, LL lamps and reap energy cost savings. Table 1 also shows that the price differential between these lamp models from supplier B is over 290%, which may be difficult to recoup in a reasonable length of time.
Of particular interest to those who choose more expensive lamps may be the question of whether the lamps are less expensive in the long run and how quickly any cost savings can be realized. The answer is dependent on many factors including system efficacy, the cost of energy, the cost of labor to install or replace lamps, disposal costs, ballast choice, lighting layout, and operating cycle. A detailed analysis of the life cycle cost benefit is needed to accurately evaluate the economics for a specific product choice. A method for analyzing life cycle cost benefits can be found in the IESNA Lighting Handbook, ninth edition (Rea, 2000). Some manufacturers also provide lighting cost calculators. However, an accurate analysis is challenging because of the uncertainties of power and rated life of T8 lamps.
What is a Fluorescent Tube?
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
Browse All Fluorescent Tubes
Different Types of Fluorescent Tubes
A number of different types of fluorescent tube have been produced since they were first introduced and patented as a commercial product in 1939. These tubes vary in terms of shape, power, rating, length, colour, and other illuminating characteristics. It’s important to take care over the choice of fluorescent tubing, considering the design of your interior space and the lighting purposes.
T2 Fluorescent Tubes
The bulbs featured within these miniature tubes have a diameter of 7mm (0.275 inches). They allow for quick connection and feature an axial base suitable for applications including the lighting of display cases, under cabinets, and display backlights. The T2 fluorescent tubes have a greater lifespan than that of the T5 alternatives. However, you must ensure that they are attached to electronic ballasts purpose-made for T2 fluorescent lamps.View Range
T4 Fluorescent Tubes
T4 fluorescent tubes have a particularly slim-fitting design and the small size of these fluorescent tubes allows for easy installation. They are commonly used for kitchen display and work-surface lighting. Such tubes emit a cool white colour, making them suitable for a broad range of applications. T4 tubes offer high levels of energy efficiency and are an excellent budget option. They have an expected lifespan of around 10,000 hours.
T5 Fluorescent Tubes
T5 fluorescent tubes are suitable for lighting offices, schools, supermarkets, and other similar environments. They are an excellent cost-saving option, particularly given their expected lifespan of up to 30,000 hours. T5 tubes also feature an eco-friendly coating on the inside of the glass, effectively preventing the phosphors from absorbing mercury. Longer T5 tubes were introduced across Europe during the 1990s. The design of these elongated tubes has been based on multiples of the 300mm (11.8 inches) ‘metric foot’, rather than the 305mm (12 inches) imperial foot. The ballasting of these fluorescent tubes prevents overloading and allows for the integration of features such as the instant, rapid, and programmed start.View Range
T8 Fluorescent Tubes
These fluorescent tubes are used for a wide range of domestic and commercial purposes, primarily because of the high levels of light emission. Such tubes have outstanding colour rendering capabilities and offer excellent levels of energy efficiency. The light given off by T8 fluorescent tubes has also proven to be effective in the prevention and treatment of seasonal affective disorder (SAD).View Range
T12 Fluorescent Tubes
The production of T12 fluorescent tubes ceased in 2012. These tubes have measurements of 38mm (1.49 inches) in diameter and have distinct wattages when compared with alternative types of fluorescent tubing. The Environmental Protection Agency (EPA) has advised the retrofitting of T12 fixtures for alternatives that don’t use as much mercury or fossil-based fuel. You may choose the option of replacing T12 fluorescent tubes with T8 LEDs due to the comparative generation of light and reduction of energy.
Circular Fluorescent Tubes
Available in T5 (15mm diameter), T6 (20mm diameter), and T9 (29mm diameter) formats, circular fluorescent tubes are commonly used by lighting designers in the creation of well-lit interior spaces. These fluorescent tubes offer high levels of energy efficiency and have a slimline design, making them the ideal option for ceiling lighting. Round fluorescent lamps are only compatible with existing circular fluorescent tube fixtures.View Range
What Can Fluorescent Tubes Be Used for?
Fluorescent tubes and lamps are available in a variety of shapes and sizes. The compact fluorescent lamp has gained considerable popularity in recent times. 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
How to Choose the Right Fluorescent Tube
The installation of fluorescent tubing may result in significant financial savings for two main reasons – low running costs and a lengthy lifespan. These lights will also provide greater levels of illumination than standard incandescent light bulbs. As previously mentioned, fluorescent tubing is suitable for a wide variety of domestic and commercial applications. The tube diameter, length, and colour rendering should all have a bearing on the buying decision.
Fluorescent tubing can provide the following colour variations:
- Warm white
- Cool white
This table highlights the wide selection of fluorescent tubing available from RS Components:
|Brand||Main Benefits||Suitable Applications|
|Philips Lighting Fluorescent Tubes||Extended life expectancy of up to 20,000 hours Shatter-resistant versions available||Schools, offices, shops, and factories|
|Sylvania Fluorescent Tubes||Energy-efficient range Improved colour rendering performance||Suitable for a wide range of applications|
|Osram Fluorescent Tubes||Advantages of a well-known brand Products available worldwide||Both domestic and commercial lighting|
|GE Fluorescent Tubes||Excellent colour quality Longer lifespan and lower mercury outputs||Domestic use, signage, industrial applications|
|GlassGuard Fluorescent Tubes||Industry compliant shatterproof linear fluorescent lamps||Retail, food industries, laboratories|
|RS Pro Fluorescent Tubes||Waterproof units Impact resistance||Manufacturing and food industries, marine environments|
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:
Compare Fluorescent Tubes
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:
|200-300 Lumens||300-500 Lumens||500-700 Lumens||700-1,000 Lumens||1,000-1,250 Lumens||1,250-2,000 Lumens|
|25-30 watts||40 watts||60 watts||75 watts||120 watts||150-250 watts|
|5-6 watts||8 watts||11 watts||15 watts||20 watts||20 watts|
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 lengths of these tubes are commonly indicated by the wattage. 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, with a length of between 340mm and 1,800mm. The length of the T8 tube may be anywhere from 600mm up to 2,400mm.
Typical Applications of Fluorescent Tubes
Varieties of fluorescent tubing can be used for the lighting of industrial, commercial, and residential buildings. They generate a shadow-free form of lighting in all instances. The T8 fluorescent tube is the variety most commonly used for commercial and industrial purposes. Other types of tubing are used to light cabinets, beams, and coves in residential properties.
How to Fit a Fluorescent Tube Safely
Considerable care should be taken during the fitting of a fluorescent tube. You should 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.