Choose high-efficiency light sources and lamps
1. High-efficiency light sources
High-efficiency light sources refer to light sources with high energy conversion efficiency. When the light source of the lamp is used, electrical energy will be converted into light energy and heat energy. The higher the proportion of electrical energy converted into light energy without wasting heat energy, the higher the efficiency of the light source. The efficiency of the light source is usually expressed in (lm/W), which means how many lumens of light can be emitted for every 1W of power input. The efficiency and life of the light source will be listed in the manufacturer's catalog. Based on economic and maintenance considerations, it is particularly important to choose a light source with high luminous efficiency and long life, and a low replacement cost. At present, fluorescent tubes are still the most practical and common.
The luminous efficiency of various light sources is shown in the table. Taking fluorescent lamps as an example, high-wattage (40W) and low-wattage tubes (20W) are more efficient, and straight tubes are more efficient than circular tubes; taking energy-saving lamps (delicate or compact energy-saving bulbs) as an example, spiral tubes (or ice cream-shaped ones) with more corners or sharp turns and PL tubes are more efficient.
In response to the trend of energy saving and carbon reduction, light source manufacturers around the world are actively developing high-efficiency light sources and energy-saving lamps. The light sources currently sold on the market are all energy-saving light sources with energy-saving designs, including delicate fluorescent tubes and energy-saving bulbs. Delicate fluorescent tubes and energy-saving bulbs do save 60~70% more energy than traditional incandescent bulbs, but they are not necessarily more energy-saving than straight fluorescent lamps. They can just use the original incandescent bulb holder, which is convenient and takes into account the appearance and aesthetics of the lamp.
Both the exquisite fluorescent tube and the energy-saving light bulb are fluorescent lamps. Since they were first successfully developed by Philips of the Netherlands, they are sometimes also called PL lamps. However, there are many types and appearances at present. They can be installed as needed and are very convenient to use.
Fluorescent tubes have evolved from T10 to T9, T8, and T5. The smaller the tube diameter, the higher the luminous efficiency, the lower the mercury content, and the more environmentally friendly they are. If T5-28W tubes are used, the power consumption of the tubes will be saved by about 10W compared with the original T9-38W. If used with a high-frequency electronic ballast, its performance can be further improved.
2. High-efficiency lamps
The main function of lamps is to change the forward direction of the light emitted by the light source so that it is projected onto the illuminated surface to be illuminated, and the amount of glare can be controlled to make the vision comfortable. Therefore, the classification of lamps is based on the distribution of the light beam in space (i.e., the light distribution curve). The percentage of the light beam (light) emitted by a certain light source in this lighting fixture that can reach the main illuminated object surface is called the lamp efficiency or fixture efficiency, which represents the evaluation of the optical projection performance of this lighting fixture (related to the lamp reflection, refraction angle design, surface treatment and the material of the reflective surface, etc.). The higher the lamp efficiency, the better, indicating that the effect of producing light on the illuminated object surface is higher.
At the same lamp installation height, direct lighting lamps have the highest efficiency, narrow irradiation area, and the strongest glare; indirect lighting efficiency is poor, but the irradiation area is wider, the light distribution is the most uniform, the glare is the least, and the vision is the most comfortable. In other words, lamp efficiency and visual comfort need to be coordinated with each other to obtain practical and economical lighting. The key lies in the nature and needs of the work in the light environment. In commercial places, bright illumination is prioritized, and lamp efficiency is given priority; home lighting focuses on comfort and warmth, and indirect lighting is suitable.
Reasonable illumination planning
Illuminance is the amount of light entering a unit area, that is, the value obtained by dividing the light beam by the area (m2). It can be used to express the brightness of a certain place, and the unit is Lux. The higher the illumination of the illuminated surface, the easier it is to identify the environment and help reading. Depending on the workplace and the needs of the operation, the illumination level suitable for the work can be set to avoid excessive design of lamps, resulting in excessive illumination and increased electricity consumption of lighting equipment. All spaces should maintain a certain average illumination requirement and strive to achieve uniform light distribution. Some places that require high illumination can use local lighting. In addition, whether it is natural light or artificial light source, the indoor walls can be decorated with bright colors to increase reflected light and improve the indoor illumination level. The lighting quality will also present a better feeling due to reflection.
Make good use of lighting system control strategy
The lighting control of lighting is mainly lighting and dimming. In response to the convenience of operation, it is necessary to combine appropriate distribution equipment, switches and various types of photothermal sensors. From simple manual switches, timing devices, detection sensors to complex scene presets and schedule setting systems, the use of automated switch and dimming control functions gives designers and managers the opportunity to fully control the indoor environment, not only giving the building space the flexibility to meet different needs at different times, but also providing space users with the necessary lighting levels at the right time, reducing unnecessary energy waste. Common control methods include:
1. Manual controls switches and dimmers
The structure is simple and easy to use. The switches of lamps include individual switches and group switches. They can be combined with preset control systems as dimming and scene switches, or combined with timer timing switches. However, there should not be too many control loops to avoid confusion, and the control panel must be marked.
2. With a timing controller (timer)
Automatically switch the lighting environment mode at a predetermined time, or control the flickering of lamps to avoid wasting energy due to forgetting to turn off the lights. For example, automatic lighting fixtures for going to work, getting off work, lunch breaks, night landscape lighting, and street lights. The time control function is based on time. It can automatically turn on, turn off or adjust the lighting facilities in a given area according to the scheduled arrangement. It is suitable for spaces where daily affairs are carried out according to routine schedules.
3. With daylight sensors or brightness detectors
When the sunlight outside is bright and sufficient, the output of the dimming electronic ballast can be automatically adjusted to reduce the light output of the lamps in the window area or directly turn off the lamps. Therefore, the circuit design needs to be configured in parallel with the window direction, which is suitable for automatic control of window-side lamps in office places, window corridors, light wells, and outdoor landscape lights at night. The daylight adjustment system is mainly used in the window area within 4 meters around the interior of the building. The daylight sensors (solar cell / photocell) placed at various points in the room or built-in lamps adjust the output light in proportion from the window to the inside according to the degree of daylight supply to reduce unnecessary energy waste.
4. Use sensors (occupancy recognition)
In some places where fewer people enter and exit, the lamps can use autonomous control lamps with additional sensors to automatically control the flickering or brightness of the lamps. For example, when someone approaches, the lamps are automatically turned on. When the person leaves, the lamps are automatically turned off after a preset time, which can avoid wasting energy.
5. Overall group control lighting control system
The use of lighting central monitoring system, two-line lighting control system, etc. can flexibly cooperate with the changing needs of the venue and monitor and manage them, which can save more than 30% of lighting electricity.
