How to replace 400w metal halide according to lumens?

400 watt metal halide lumens
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This article is intended to tell readers how to find the best replacement to replace 400 watt metal halide.

No time to browse long text, please read here:

The light efficiency of metal halide is generally 80-100lm / w, so it needs to be replaced with 32,000-40,000 lumens LED highbay lights.

I believe many people know that 400 watt MH product cannot be replaced by led high bay lights of the same power, but should be replaced by led luminaires of lower power. Yes. That's right. Many led lighting suppliers will directly provide less than 400 watts based on wattage, but are they really right? It doesn't matter, wait until you read this article before you make a judgment.

In order to explain more clearly, I am going to explain how to replace based on the data information provided by the customer:
400w metal halide light effect: 80lm / w. Lights up 10 hours a day, 5 days a week. It has been used for 3 years.

When you are sure that you want to convert to led lights, first understand

  1. What is Light efficacy?
  2. What is the lumen?
  3. What are the initial lumen and L70 rating?
  • Answer 1: The ratio of the luminous flux emitted by the light source to the power consumption is called luminous efficiency, and the unit is lm/w. Different light sources emit the same luminous flux, the lower the power consumption, the higher the luminous efficiency. The higher the luminous efficiency value, the stronger the ability of the lighting product to convert electrical energy into light energy. In the case of providing the same brightness, the energy-saving of this light is stronger. At the same power, the stronger the illuminance, the greater the brightness. LED products can reach 130lm / w-150lm / w.
  • Answer 2: Luminous flux refers to the radiant power that human eyes can feel. More lumens means brighter light
  • Answer 3: L70 refers to the time it takes for the light decay to become 70% of the initial lumen value. This period of use is also the life of the lamp.

After understanding these professional terms, then when I compare them, you can better understand.
According to the data provided by the customer, the total lumens of the 400 watt metal halide was 32,000 lumens, but due to the fast light decay, in the half-life period, the total lumens of the original lamp will be reduced to half, namely equal 16000 lumens. Judging from the length of use of the customer, they are already in half-life. So if you want to replace the original lumen of the old one, please use the led fixture with luminous efficiency * Watt = 32000 lumens. If you only need to achieve the same as the half-life, you can choose the same light effect, but lower wattage led lights.
Did you discover it? We do not calculate base on power, but base on lumens. Even so, it can only give approximate data.

The specific wattage of the replacement cannot be determined due to the influence of the luminous direction, reflector, CRI, installation height, lighting range, etc.

For example, a traditional fixture (HM, HPS, HID fixture)emits light at 360 degrees. In order to focus the light on the desired spot, it needs to add a reflector to direct it. This means that it will lose 30% of its light output. If the initial lumen of the metal halide bulb is 32,000, the loss caused by the reflected lumen will reduce to 20,000 lumens. The led light is directional. When the installation height is very high, you can choose a lens with a small beam angle to achieve more light on the ground.

metal halide vs led

Benefits of using LED lighting product

  1. Slow light decay and long life.
  2. The LEDs are directional and there is no loss of light output due to the reflector.
  3. Increase the induction function, when there is no work under the luminaires, the brightness is halved, saving costs.

Therefore, how many led lumens do you need? According to the actual situation, rely on Dialux or photometric method to simulate and comprehensively analyze the data to get accurate results. Need simulation, please contact us, we can provide you for free.

Dialux for warehouse lighting

However, in the history of selling led lighting for nearly 10 years, our general rule of thumb is (taking quality high bay lighting as reference):

  • 10-15 feet, the lights that should reach 10,000 to 15,000 lumens.
  • 15-20 feet, the lighting that should reach 16,000 to 20,000 lumens
  • 25-35 feet, the fixtures that should reach 33,000 lumens.


There are many 400w metal halide led replacements on the market, you can find lights fixture with output over 100 lm/w (whether it is a brand new led luminaire or led bulb). If you have invested a lot in the retrofit kit, then it is recommended that you buy led bulbs to install. If not, please choose the new LED highbay lights, it will be the best replacement for 400 watt traditional lamps. If you choose a reputable company to provide high-quality products, you can achieve an output power higher than 140 lm/w. This allows you to reduce the power consumption of each luminaire by 2-3 times and sometimes by 4 times. When you replace many lights, this will save a lot of energy.


Read more
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Retrofit high bay to LEDs

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