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Do Grow Lights Produce Heat?

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Grow lights are useful when you are growing microgreens inside a closed space that’s unable to supply natural sunshine. Photosynthesis needs to be supported naturally, and growth lights aid the process. But do grow lights produce heat?

Yes, every light emits heat. When electricity travels through the diode’s flawed crystal structure, what does not turn into light energy is converted into heat energy. No matter where the light is coming from—a bulb, a diode, or a star like our sun, all generate heat.

Microgreens can be grown all year round with the use of low-heat LED grow lights, provided the plants receive the proper care. It essentially gives them the appropriate amount of light and temperature.

Therefore, knowing about grow lights is essential for gardeners. You will learn various essential information about grow lights in this article.

So, let’s begin.

Do Grow Lights Produce Heat
Galaxyhydro Grow Light – via Flickr

What Does Actual Wattage in Grow Light Mean?

A common misunderstanding about grow lights that need to be cleared before we continue further is wattage ratings as brightness. Brightness is not measured in watts. It only measures how much electricity is taken from the wall outlet.

Naturally, we assume a higher-wattage bulb to be brighter and provide more coverage to green plants. Wattage has become synonymous with brightness in our minds. We get a higher-wattage light bulb if we desire a brighter bulb.

However, a certain amount of watts is needed per square foot depending on the plant being grown. Also, it is crucial to use low-heat grow lights and to keep an eye on the humidity and temperature levels to maintain ideal growing circumstances.

What is the Science Behind Heat in Grow Lights?

The physics underlying how grow lights produce heat is based on the law of thermodynamics. In general, heat is produced from the conversion of electrical energy into light energy when electricity is used to power light.

The bulbs, dimmers, and every other part of grow lights produce some heat. The efficiency of the machinery and the amount of electricity utilized by the lights both directly impact the amount of heat generated.

The kind of bulb used and the amount of heat produced are also factors in heat generation. For instance, due to the lower energy efficiency of incandescent bulbs, they generate more heat than LED bulbs.

It is important to understand how grow lights produce heat as the temperature, and humidity levels in an area may be affected by their heat, which may impact the health and development of plants.


Does Using a Grow Light Help Plants?

Although using grow lights is not required, they are useful if there’s not enough natural sunshine. As already mentioned, an important question in indoor gardening is do grow lights produce heat or not.

But, using grow lights matter a lot in the growth of plants as there will be variable amounts of natural light in your home, depending on where you position your microgreens. It is not possible to supply adequate sunlight throughout the year, so we must supplement it with grow lights. Giving microgreens the proper quantity of light is essential to growing them properly.

You can’t just use whatever lamp you have at home and think that it will be sufficient. Although you would believe that a bright bulb will promote plant development, microgreens require a broad spectrum of light to thrive. They require this for germination and photosynthetic processes.

Regular LED grow lights are too hot and don’t give enough light too. Quality grow lamps that are effective, produce the right light, and have little heat are worth the investment.

What Advantages Do Grow Lights Offer?

Grow lights are excellent for growing microgreens if you are unable to supply natural sunshine. LED grow lights can be used in the absence of natural sunshine, enabling year-round indoor plant cultivation.

The advantages grow light offers are:

  • They evenly distribute the entire light spectrum throughout the microgreens.
  • The number of hours that light is provided can be modified in grow lights. Hence, microgreens can thrive in proper sunlight hours by setting a timer. You must also give your microgreens a break, regardless of the kind you are cultivating.
  • Grow lights help in maintaining a consistent temperature. They do generate some heat, but by leaving them on all day, you can maintain a constant temperature.
  • Grow lights help in promoting the growth of your microgreens. Microgreens cannot develop well without enough light, as photosynthesis cannot take place.
Do Grow Lights Produce Heat
White Full-Spectrum LED Aspect Grow Light – via Wikimedia

Do Grow Lights Get Hot Enough to Start a Fire?

Misuse of any technological gadget poses a danger of fire. When using grow lights, there are a lot of things you should keep in mind. But do grow lights get hot enough to start a fire?

Yes, if grow lights are not handled properly, or they break down, they can become hot enough to cause a fire. Grow lights must be used in a place with good ventilation and away from anything flammable.

Grow lights should also be frequently checked for wear or damage and, if necessary, replaced if not operating properly. Also, avoid watering your microgreens in a way that would wet the growth lights. Take note of how you water your plants, as all grow lights might not be waterproof.


Low-heat grow lights produce a complete spectrum of light required for indoor plants’ proper growth. But do grow lights produce heat too? Grow lights do produce heat, and they must be properly used in an indoor environment for the growth of plants.

You must think carefully about the type of lighting you plan to employ. Choosing an incompetent light will harm your microgreens by producing too much heat which will burn the leaves. Burning of leaves due to excessive heat is one of the most common issues gardeners face while using a bad grow light.

Low-heat LED grow lights are a great option to grow microgreens if you have an indoor setup to put grow lights, as they are low-energy lights and don’t generate plant-burning heat.