Plant growth lights are beneficial for maximize increasing the yield and quality of crop, and are widely used in vegetable, fruit and other crop industries. At present, there are common three types of lights used in the market, such as: HID light, LED growth lights and CFL and T5 light, etc. , what are the difference between them?Le me explore these detail by this guide.
HID is the highest electro-optical conversion efficiency and the widely used as plant light source . there are two types of HID lights:
Metal halide light
Metal halide light can produce a number of blue light that helpful for promoting plant growth, especially for green leafy plants. Blue light makes plants more compact and robust. If there is no sunlight or insufficient sunlight ,it is very suitable as the main light source to provide the light for plants. The working time of the metal halide light is about 10,000 hours. Over this time, the light will decrease the luminous efficiency sine its aged (more electric energy becomes heat dissipation).
High pressure sodium light
The light emitted by the high-pressure sodium light is mainly red-orange, and also includes a small amount of blue light that helpful for promoting the flowering and bear fruit. High-pressure sodium light is also a good light source option when insufficient sunlight, therefore, high-pressure sodium light are also widely used as growth lights.
There are other reasons for the large-scale application of high-pressure sodium light in the past.
High long life:it can reach twice that of a metal halide light, but when the bulb is aging, it will consume more power and emit less light that means the luminous efficiency will drop sharply.
High luminous efficiency: A 1000-watt bulb can reach 140 lumens/watt, and a 100-watt bulb can reach 105 lumens/watt.
High-pressure sodium lamps also have disadvantage: Low the proportion of blue light. In the process of raising seedlings, if a sodium lamp is used alone, which may cause the leaves slim. If you like,click here know more HPS light vs LED growth light.
The difference between metal halide light and LED light
Metal halide light:
The metal halide light is a light fixture that produces arc discharge in the mixed vapor of mercury and rare metal halide. The metal halide light has the characteristics of high luminous efficiency, good color rendering index.
The arc tube is filled with mercury, inert gas and more than one metal halide,when tube filling with different kinds of metal halides,it can improve the color rendering index (the average color rendering index Ra is 70～95),the luminous efficiency of the light can be as high as 120lm/W or more.
LED (Light Emitting Diode), is a solid-state semiconductor device that can convert electrical energy into light. The core of the LED is a semiconductor chip, one end of the chip is attached to a support as the negative pole, and the other end is connected to the positive pole of the power supply, and the entire chip is encapsulated by epoxy resin.
The differences between metal halide light and LED light are: light source type, excess energy dissipation method, light fixture housing temperature, vibration resistance, light distribution performance and resistance interference performance.
The difference in light source type:
Metal halide light are heat light sources; LED are cold light sources.
The difference in excess energy dissipation:
Metal halide light dissipate excess energy through infrared and ultraviolet light but infrared and ultraviolet light will affect itself quality and human healthy;
The heat through LED generates heat is very easy to control and conduction.
The difference in the temperature of fixture housing:
The temperature of the metal halide light housing is very high, which can exceed 130 degrees;
The temperature of the LED light housing is low, normally below 75 degrees. The lower temperature of the fixture housing can greatly increase the safety and other accessories lifespan,such as cables, wire,connector( If possible, it is better to use shine industry connector, because it is one of the best waterproof connector manufacturers in the market) etc.
The difference in vibration resistance:
The filament and bulb of the metal halide light are easily damaged and have poor vibration resistance;
The light source of the LED light is an electronic component, high anti-vibration.
The difference in light distribution performance:
The light distribution performance of the metal halide light is difficult,resulting in large energy waste and uneven the light spot.In addition, It needs a large reflector,adding the size of light;
The LED light distribution is very easy to control, which can achieve a variety of light distributions and uniform light spot under the same volume, which is beneficial for reducing the waste and improving the luminous efficiency.
The difference in anti-interference performace
Metal halide light: Poor, the light power changes with the voltage fluctuates, and it is easy to overload;
LED lights: stable, constant current power drive and keep the light source power constant when the voltage fluctuates. it can work normally during the voltage from 90-265 volts.
The difference between LED growth light and metal halide Light
Metal halide light,HPS light and led lights are used as plant growth lights,some people choose LED plant growth lights. Some people choose other light fixture since they think the cost of LED plant growth lights is high,So,in addition to the price factor,what is the difference between led growth light and metal halide light?
HPS light pros and cons:
Strong penetrating power,
mainly used in stations, airports, and highways
The spectrum of the high-pressure sodium light is basically linear, and it does not match the plant photosynthetic absorption spectrum ideally.Plants only absorb the light of individual wavelength bands, resulting in energy waste.
Moreover, The temperature is high when working, and it is easy to burn the plant if it is too close to the plant, while it is not ideal when too far away.
Contains heavy metal mercury;
High temperature on the surface and not safety;
The low color rendering property;
Short lifespan,only about 4000 hours;
If unstable voltage，it is very easy to failure.
Metal halide light pros and cons:
It can reach 100LM per watt, and the color rendering index is higher than 90, which is more suitable for industrial lighting
Short liferspan,only about 1000 hours
contains heavy metal mercury and rare halides;
High temperature on the surface and not safety;
LED plant growth lights pros and cons:
Light is one of the important and indispensable factor for plant growth. Light replenish and regulation is an important technology in the field of facility cultivation. The direct influence of plant photosynthesis is mainly red light and blue light spectrum,and red light wavelength at 630~660nm,which is to help plants to bear fruit. Blue light wavelength at 450~470nm, which is to help plants grow stems and leaves.
Energy saving, environmental protection, low carbon, high color rendering index, right light spectrum for plants.
High initial cost
A 120W LED plant growth lamp is equal to a 400W metal halide light or a high pressure sodium light.
If 120W LED plant growth light will work for 10 hours a day, that is 1.2 KWh.
If a 400W metal halide light will work for 10 hours a day, it will cost 4000W,that is 4.0KWh.
We suppose a greenhouse room need 50 set light fixture,how much electricity does need per day?
LED plant growth light
120W X (10 hours) X 50 units = 60 kWh
Metal halide light
400W X (10 hours) X50 units = 200 kWh
Through above count,we know that LEDs are energy saving, environmental protection and low operation cost option.
Through this guide, we know that HID light including HPS light and metal halide light, and the advantages and disadvantages of LED plant light.
In summary , in terms of energy-saving , LEDs are more energy-efficient, only about a quarter of the energy consumption of high-pressure sodium light and metal halide light. In terms of applicability, high pressure sodiumlights are more suitable for road lighting because of high penetration, metal halide lights are more suitable for commercial streets. if they are used as plant lights, HPS light and metal halide light are only suitable for greenhouses,not suitable for multi-layers-plant factories.Moreover,high-pressure sodium lights and metal halide light are also not suitable for the seedling stage, LEDs are suitable for all stages of plant growth. In terms of cost, high-pressure sodium lights and metal halide lights are much cheaper than LEDs. In terms of lifespan, high-pressure sodium lights and metal halide lights have a much shorter lifespan (only one-half) than LEDs.