For a long time, metal halide lights have been used in the field of high-power lighting. However, as the using time increases, their efficiency will drop sharply, resulting in energy waste. Therefore, new metal halide lights have to be replaced to keep the brightness required.However,LED lights are more energy-efficient and more and more used.
Whether your warehouse or other lighting projects still use outdated metal halide lights,would you want to replace them with the latest LED high bay light? Therefore, how do we start? How many high bay lights do I need?Before replacing metal halide light with LEDs, let’s first look at some basic knowledge.
Can you use a LED bulb in a metal halide fixture?
LED lights are a good alternative to metal halide light. High-efficiency LEDs lights allow you to consume less electricity to obtain the requirement for lighting. The question is can I directly replace them with LED bulb,which be determined according to the actual application. The latest LED technology allows the simplest way to replace of your metal halide light.
When replacing of metal light with LED light, there are two situations including whether using the ballast or removing the original metal light ballast. If you do not want to remove the original ballast, then you only need to choose the LED light with almost lumens as before. At this time, there is no need to re-wire or change anything. In this application,you should first understand which ballast used to better choose the correct LED type.
Generally speaking, there is an ANSI code on the ballast. The ballast of the metal halide light starts with M, followed by 2 or 3 codes, for example: “M59” means a 400W ballast.
If you plan to remove the ballast and work directly under DC voltage, then it is recommended to choose a wide voltage LED bulb, which can work normally under different voltages between 120-270. In this application, you only need a professional engineer to remove the original reflector or metal halide light ballast and provide DC voltage to the socket, but you need to consider whether the bulb matches the socket. There are E26 or E39 or EX39, base etc available.
How to convert metal halide to LED
If you use a 400W metal halide light before, how many watts of LEDS should I need?
Many people should know that LED lights are more efficient, so the lumens produced by 400W LED high bay lights are greater than that of metal halide light. In other words, we should choose LED high bay lights with lower wattage, but we only know LED light will be required below 400W, However,how many watts of LEDs can meet our lighting requirement, 100W, 200W or 300W? How to determine? Don’t worry, we will introduce the conversion processing in detail next.
To explain the replacement wattage more clearly, we first need to know some basic information, such as the original 400W parameters and light usage condition.
The original 400W metal halide light is 80LM/W, used for 10 hours a day, and has been used for 3 years.
Now we want to replace these 400W metal halide lights with more energy-saving LEDs. Before upgrading it, let’s first know some light terms.
What is light source efficiency?
The luminous efficiency of a light source refers to the ratio of the luminous flux emitted by a light source to the electric power consumed by the light source,and the unit is Lm/W. Under the same luminous flux, the higher the electric power consumed, the lower the luminous efficiency. Under the same power,the higher the luminous flux emitted by the light source, the higher the efficiency of the light source. In other words, under the same power, the higher the efficiency of the light source, the greater the illuminance and the higher the brightness. Today, the light source efficiency of LEDs can reach 130lm/w- 150lm/w,while the lumen efficiency of metal halide light is about 80-100Lm/W, so the lumen of 400W metal halide light is between 32,000-40,000 lumens.
What is the luminous flux maintenance rate?
The luminous flux maintenance rate is the ratio of the luminous flux of the light used for a period of time to the initial luminous flux of the light. L70 means that the luminous flux has decayed to 70% of the original luminous flux, L80 means that it has decayed to 80% of the original luminous flux, and L90 means that it has decayed to 90% of the original luminous flux.
All right, what is the next step? As above, the total lumens of a 400W metal halide light is 32,000 lumens. If you want to obtain the brightness of the initial light , you can buy LEDs light with roughly the same lumens. If you only want to obtain the brightness of the metal halide light used for 3 years ,you need to calculate the luminous maintenance rate, because the brightness of the metal halide light after 3 years is not as bright as the beginning. If the luminous flux maintenance rate of the metal halide light after 3 years is L70.Therefore,the total lumens becomes: 400*80*0.7=22,400 lumens.
We only need to choose the LEDs light with the approximate lumens above, and you will find that the wattage of LED light is much lower that of 400W metal halide light.
In fact, there are many other factors that affect the actual brightness on the floor, such as the beam angle, reflector, installation height, etc., it is hard to determine the specific wattage.
For example,the metal halide light can emit light with 360 degree,so it needs to be equipped with a reflector to focus the light to a certain direction, which means that there is light output loss that is closely related to the quality of the reflector. If a high-quality reflector is used, it may be the loss rate is between 10-15%. If a general reflector is used, the loss rate may reach 30%. Therefore, even if a 400W metal halide with 32,000 lumens, it will be reduced to 2,000 lumens after the loss. There is a variety of beam angle options fro LED high bay lights, such as 60, 9, 120, according to different heights, choosing different beam angles to illuminate a larger area under the same wattage.
In practical applications, the lumens required for different heights are below:
10-15 feet, 10,000 to 15,000 lumens required.
15-20 feet, 16,000 to 20,000 lumens required
25-35 feet, 33,000 lumens required.
WHAT LED is equivalent to 400W metal halide?
The 400W metal halide light is equivalent to LED lights between 120-150W. How to calculate it? We need to use the previous terms of light efficiency. Generally speaking, the efficiency of metal halide light is 80Lm/W, so 400W metal halide lights are about 32,000 lumens, but this is only the ideal lumens under the 100% light output.
However,the actual lumens of metal halide light cannot be reached 100% output, because the light emitted by the metal halide light is 360 degree,which needs to be equipped with a reflector to change the light path. Therefore, after the loss of the reflector and cover, the efficiency of the metal halide light is about 50%-70%,and the actual lumens is between 16000- 22400 lumens.While the LED light source efficiency is about 130Lm/w-150Lm/w, so the 400W metal halide light is equivalent to LED lights between 120-150W.
Although metal halide lights have a variety of applications, such as street light, plant light and warehouses lighting, etc., the longer they are used, the lower the efficiency of the lights and the higher the energy consumption,replacing the metal halide lights with LED is a good solution.A energy-saving LED light will greatly improve the efficiency of light and reduce electricity bill.
Before replacing these lights, we can first calculate the approximate budget. If the budget is limited, we can only replace the LED bulbs without updating any other. If the budget is enough, we can use full new LED lights. The LED high-power kit can not only reach the ideal light output, but also greatly improve the efficiency of the light,and the longer the run, the more cost-effective.