Luminescence. A curious effect caused by gas when electricity passes through it, as M. Lomonosov also noticed many years ago. Later, many well-known scientists were involved in this: Heinrich Geisler, Nikola Tesla, Thomas Edison. They all worked to obtain another light source and contributed to its development. Only Edmund Germer in 1926 proposed the design of a fluorescent lamp in the way we know it today.
The principle of its operation is quite simple: a glass tube filled with inert gas and mercury vapor. The electrodes are inserted into the tube ends. From one electrode to another the electrical current passes through the length of the tube. This discharge causes ultraviolet radiation. UV radiation is not visible to the human eye, so the walls of the glass tube are covered with a special substance – a phosphorus that absorbs UV radiation and begins to shine in visible light. To start the lamp and maintain it, two more devices are needed: the starter, which starts the lamp and the ballast, to limit the discharge current.
After some improvements, fluorescent lamps have made a real revolution in the lighting industry. This is not surprising: they gave a luminous flux five times bigger than the incandescent lamp of the same power. In addition, the lifetime of fluorescent lamp is from 2000 to 50000 hours, compared to 1000 hours for incandescent lamps.
It is not surprising that fluorescent lamps have found a widespread use: in offices, in businesses, in warehouses, in utility rooms, including the street. It was avoided to be placed only in residential areas and in rooms with working mechanisms. This is due to the fact that the fluorescent lamps do not emit uniform light but flicker at a double frequency of the power supply (100 Hz). For residential spaces, this light has sometimes been unpleasant, and when working with moving mechanisms is even dangerous – the stroboscopic effect could create the illusion that the equipment is stationary while it is operating and this could cause accidents.
Lighting Comparison: LED vs fluorescent.
Gradually, a new generation of fluorescent lamps emerged – more economical in terms of energy consumption. Those were lamps that work on the same principle but have a more compact design and were made under the E27 standard – as incandescent lamp. They are increasingly replacing the incandescent bulbs, which have begun to disappear.
But all this has changed with the invention of the white LED. If the first generation of LEDs were similar to the characteristics of fluorescent lamps, the latest generation leaves behind all the fluorescent lamps in all aspects, except for the price. LED lamp overtake fluorescent lamps by their advantages:
- profitability. The power of the fluorescent lamps is about 60 Lm/W, while the modern LED lamp reach 160 Lm/W;
- frequent start-up causes intense wear of fluorescent lamps and an increase in energy consumption. In addition, at low temperatures, the fluorescent lamp may not start at all. LED lamp bulb can easily support frequent starts and low temperatures;
- chemical hazards. Fluorescent lamps contain an amount of mercury between 2.3 mg and 1 g. In EU, a special directive was issued that prohibits the use of fluorescent lamps;
- the pulse factor. Fluorescent lamps are pulsing during operation and this is tiring for the eyes and can cause an industrial accident. The LEDs illuminate uniformly without pulsation;
- degradation of phosphorus during operation results in a spectrum shift, a decrease in light quality and, as a consequence, a decrease in efficiency. LED lamp light is also subject to degradation, but this process takes many years;
- mechanical resistance. The fluorescent lamp is a glass bulb and can be easily damaged, while the LED lamp bear quite significant mechanical loads without consequences;
- the sound emitted, necessary for the operation of the fluorescent lamp, often causes an annoying hum;
- the very low power factor of the lamps – such lamps are not suitable for the electrical grid (balanced by the use of very expensive electronic ballasts with power factor correction). LEDs do not need such adjustments.
Thanks to all the advantages of LED lamps, they replace fluorescent lamps in all areas of application: both outdoor lighting and interior lighting.
LED lamp manufacturers exceed consumers expectations regarding LEDs with a fluorescent lamp-like design, LED lamp body is similar to fluorescent lamp body and to replace LED lamps, it’s only necessary to remove the fluorescent lamp from the luminaire, disconnect the throttle acceleration and starter and installing the LED lamp in the luminaire.
In addition to all the above advantages, LEDs have dimming properties – to reduce brightness when possible. However, the fact that LEDs are not afraid of frequent starts and stops. This allows them to be used with light sensors and motion sensors and helps to avoid a situation when someone forgets to turn off the lights. When using LEDs with a light sensor or motion sensor this situation is impossible, which helps save energy and protect the environment.
Due to the LED design, an entire family of lamps of different shapes and sizes has been developed for various applications. There are cylindrical tubes to switch from fluorescent lighting to LED light. There are built-in LED panels that fit perfectly in designing the ceiling of the office space and emit uniform light without flickering and shining.
For use in warehouses, supermarkets or industrial areas, lamps with a special modular design are made – tripods. They are distinguished by a hermetic and more durable carcase to protect against the possible exposure to moisture. Lamps of this type are designed to operate under more severe conditions than offices. Due to a special mounting and connection scheme, as well as a modular design, the installation of the lighting system built on such lamps does not cause any difficulty. Built-in human presence sensors, a motion sensor and a dimmable power supply make the lamp work as economically as possible.
At first glance, it may seem that when using economically efficient fluorescent lamps or much more economical LED lamps, it is nonsense to use sensors to get even more savings. Well, how much can you save there? This is the case when 5-10 bulbs are used. The figure is not really impressive. But when it comes to large installations, such as a supermarket, where there are thousands of lamps in the sales area, without counting the deposits and annexes. In this case, the electricity savings reach an impressive value. In addition, saving energy means reducing carbon dioxide emissions into the atmosphere! The European Union is granting a lot of importance to this issue.
Fluorescent lamps are a wonderful invention. They have given light to mankind for decades. But their time has passed. Considering all the benefits that LEDs offer: cost efficiency, quality, safety, ecological appearance, installation flexibility and ease of maintenance, it is obvious that continuing to use fluorescent lamps is simply unreasonable, and in EU countries will soon become impossible. But that’s for our sake. If there is a modern product that has the best properties and allows us to save the environment, why not to use it?