LED lamps are gradually entering our everyday life to illuminate houses, which are replacing incandescent, halogen and fluorescent lamps. In order to determine the need for such a replacement, it is necessary to compare the characteristics of different types of lighting fixtures. So, let’s figure out what is better LED lamps or energy-saving, or maybe incandescent lamps?
The main characteristics of lamps for lighting
The main technical parameters by which the quality of lighting lamps are determined include:
- power consumption;
- light flow;
- lamp life;
- structural strength;
- dimensions and weight;
- environmental friendliness.
Along with these characteristics, the following indicators are of great importance:
- spectrum and color rendering;
- the ability to adjust the light;
- light direction.
The most important indicator of the quality of a lamp is the power it consumes. This value shows the efficiency of the lighting device.
The luminous flux characterizes the amount of light emitted by this device.
The efficiency of lighting lamps of this type can be assessed by such an indicator as light output. Light output is equal to the ratio of the luminous flux to the power of the device. It shows how much luminous flux the device can emit when it consumes a power of 1 watt.
The most important indicator of the reliability of lamps for lighting is their service life, which is determined in hours. The longer the service life, the more reliable the lamp and the longer it will not burn out.
Comparison of LED fixtures with other types of lamps
For comparison, the following types of lighting devices will be considered:
- LED lamp. The main element of such a lamp is an LED that emits light when current passes through it;
- incandescent lamp. This is the most common type of lamp. It uses the radiation of a metal filament in a glass bulb. Due to low efficiency and reliability, such lamps are being replaced by more modern devices;
- halogen lamp. It uses a tungsten filament as an emitter, placed in a flask with a buffer gas. These devices have better characteristics than incandescent lamps;
- fluorescent (“energy-saving”) lamp. This lamp is a gas-discharge light source. In this case, the discharge of electricity in mercury vapor causes the glow of the phosphor layer. These types of lamps are more efficient than incandescent lamps.
|Luminous flux, lm||700||700||700||800|
|Light output, lm/W||10||16||47||80|
|Color rendering index||90-100||70-90||75||80-100|
|Service life, hour||1000||2300||8000||50000|
|Environmental friendliness||yes||yes||no (mercury)||yes|
Table 1 shows the main characteristics of lighting lamps. For comparison, various lamps are taken that emit a luminous flux of approximately 700-800 lumens.
As can be seen from the table, to obtain such a flux of light, the highest power of 75 W is required for an incandescent lamp, and the lowest power of 10 W is consumed by an LED lamp. Halogen and fluorescent fixtures require 45W and 15W, respectively.
Thus, the efficiency of each of these lamps is determined by the light output, which takes into account a variety of parameters of the lighting device, such as efficiency, the presence of a diffuser and reflector, and so on. LEDs have an average light output of 80 lm / W, but can reach 150-170 lm / W. This parameter shows that LED lamps save energy, which reduces lighting costs.
The color rendering index of an incandescent lamp is closest to ideal (sunlight). Conventional fluorescent lamps have about 75. For lamps of this type with a 5-band phosphor, the index can reach 90. LED lamps have a light transmission index of about 80-100, which is considered comfortable for the eyes.
The greatest pulsation of light occurs in fluorescent lamps. Due to the thermal inertia, the filaments of incandescent lamps and halogen lamps have a ripple that does not exceed 5%. In cheap LED lamps, the light ripple can reach 30%. To obtain low ripple in these lamps, it is necessary to use high-quality drivers. It should also be borne in mind that the use of dimmers with width modulation to adjust the light intensity can increase the pulsation of the LED lamp.
The reliability of the LED lamp (50,000 hours) also greatly exceeds the reliability of other devices, especially incandescent lamps (1000 hours). Due to this, for lighting with LED lamps, a smaller number of devices will be required, which will need to be changed much less frequently.
During the operation of light devices, part of the energy is spent on heat generation. At the same time, up to 80% of electricity is spent on heating in incandescent lamps, up to 65% in halogen lamps, 25% in fluorescent lamps, and only 2 – 5% in LED lamps. At the same time, the incandescent lamp heats up the most, and fluorescent and LED lamps heat up the least.
Important! With strong heating (more than + 80 ° C), degradation of the pn junction may occur, as a result of which the luminous flux will decrease and the quality of light will deteriorate. In order to prevent overheating of the transition, LED lamps usually use an aluminum heatsink.
From a structural point of view, the most durable and resistant to vibration is the LED. The housing of the LEDs is made of durable grades of plastic or epoxy resin. Flasks of other types of devices are made of glass, which makes them very fragile.
For the environment, only fluorescent lamps that contain mercury vapor are dangerous. The presence of mercury must be taken into account when disposing of such lamps, which is not always fully done. Another disadvantage of fluorescent lamps is the flickering of light. This phenomenon sometimes makes lighting uncomfortable and can adversely affect a person’s vision.
An important indicator for lamps of various types is the quality of light. It can be assessed using two indicators:
- color rendering index;
- Colorful temperature.
The first indicator of the quality of fixtures characterizes how close the color of an object when illuminated by a given light source is relative to the color displayed under ideal (natural) lighting. The values of this indicator for various lamps are given in Table 1.
The second indicator characterizes the shades of light emitted by the lamp and is calculated in degrees Kelvin (K). Color temperature is an important parameter when choosing a lighting device, as it affects the comfort of work and rest. For example, labor productivity will be higher when illuminated with shades of white light (3000-3500 K), so such lamps are installed in offices, libraries, and shops. Residential areas are illuminated with more comfortable and relaxing warm light (2700-3000 K) or neutral (3500-4000 K). Cold shades of light are used in supermarkets and hospitals, and daylight shades are used in museums, exhibitions, and galleries.
Table 2 – Color temperature:
|light type||Temperature||incandescent lamp||Halogen||fluorescent||LED|
The table shows that only LED or fluorescent lamps are produced for the entire spectrum of color temperatures. Thus, if you want to change a traditional incandescent lamp, then among the energy-saving ones you can easily find an analogue in terms of the type of light.
An incandescent lamp has the most pleasant spectrum for perception with a maximum at a wavelength of 550-560 nm, which corresponds to the maximum spectral sensitivity of the human eye. It is close to the emission spectrum of a black body with a temperature of 2700 K, but with a slight redshift. The spectrum is continuous.
The halogen lamp also has a continuous spectrum, similar to the spectrum of an incandescent lamp, but even more shifted towards red.
The spectrum of a fluorescent lamp is discontinuous. At the same time, inexpensive lamps have a dip in the most sensitive place for the human eye (530-550 nm). Therefore, when illuminated by such lamps, objects will look distorted. For example, at a wavelength of 530 nm, the object will be darker.
The spectrum of inexpensive white LED lamps is a curve with a peak at 450 nm and 550 nm and dips at 500 nm and more than 600 nm. The peak at 450 nm is associated with the main emission frequency of the blue LED, and the peak at 550 nm is associated with the re-emissions of the yellow phosphor. With these characteristics, color distortion is also possible.
- A comparison of four types of lamps showed that LED lamps are the most promising.
- The main advantages of lamps with LEDs are their efficiency and high reliability.
- They provide good color reproduction and, with the right choice of the supply driver, low light ripple.
- LED lamps can provide light in a variety of colors, allowing them to replace less efficient light sources in a variety of applications.