Have you ever noticed some heat sensation on the back of your hand while you place them right under the grow lights for a few seconds?

This would probably be experienced by every grower because of the fact that grow lights emit a certain amount of heat while they convert electrical energy into light energy, commonly known as “electroluminescence."

So, is it safer to say that grow light keeps plants warmer? Yes, every grow light produces heat, whether it’s LED, HPS, or Fluorescent. It's just that different types of grow lights have different heat production capabilities.

Grow lights are indeed valuable resources that serve as an alternative to sunlight in indoor planting cultivation. They’re built to provide indoor plants with enough light energy to perform photosynthesis.

Ideally, these grow light chambers don’t function as a primary source to offer warmness to plants, but because they do emit heat, they may make the internal grow room warmer.

If you’re a physics student, you must have known that any device that consumes electrical power tends to generate heat - whether it’s traditionally a bub, diode, or panel. Full Spectrum LED grow lights, being technologically more innovative, consume less electricity and, therefore, emit less heat than their conventional light sources.

To get to the root of knowing more about “Do grow lights keep plants warmer”? You need to keep reading this guide till the end!

1. Introduction

Brief Overview of Indoor Gardening and Its Significance in Plant Growth.

Indoor gardening translates as a process of growing your plants in an artificial setup where you need to put in human-made resources for plants to grow.  By human resources, we mean setting up grow lights, maintaining a growing space, and controlling other environmental variables such as temperature, water, and humidity.


This process essentially requires understanding the plant growth journey and working accordingly to arrange and manage each part of the system so that it can align to produce the best results.


The reason for bringing plants indoors can be attributed to either cold temperatures outdoors that prevent growing your desired produce, lack of outdoor space, or wanting to pick your own herbs indoors.


No matter what your reasoning behind it, indoor gardening can indeed be incredibly fun and rewarding to do.


The significant advantage that seems like a big plus point for growers is that they can control all the factors and adjust the parameters in the plant's best interest.


By that, we mean arranging suitable temperatures, light intensity, optimal spectrum, and uniformity throughout the course of the plant life.


Obviously, this raises many concerns regarding the optimal development of plants that otherwise would be ideal under sunlight.


But as technology has already provided enough solutions to everything, the latest grow lights, such as led grow light Full spectrum, are there to replicate the sunlight and provide precisely the same environment as that under the sun.


These LED grow lights have gained popularity for indoor gardening due to their energy efficiency and spectrum adjustability. Integrating high-quality LEDs can open doors for commercial breeding projects, ultimately creating great economic interest.


The Concept Of Heat Emission From Grow Lights And Its Relevance To Plant Health.

No matter what grow light you choose to put inside your growing setup, one thing is for sure: these grow lights will discharge a certain amount of heat, and you need to make an arrangement to handle the excessiveness.


The reason these light sources have this heat-generating characteristic is due to their physical makeup.


When electricity is passed through the semiconductors, the light is converted into usable energy, and the rest is produced as heat as a by-product, just like your cell phone charger or computer gets hot after being plugged in for a while.


When electricity is converted into light, it causes the surface to absorb some amount of the energy. The atoms in light move fast, and the fast movement causes the sensation of heat.


Though this heat is effective in cultivating healthy plants, but going beyond a certain threshold can be harmful at the same time.

Even the Grow light, High-Intensity Discharge (HID) bulbs possess a gas that gets activated when an electric current is passed through. Though this excitement causes the gas to emit light, it also emits heat due to the resistance of the gas to the current. This heat is then discharged from the bulb, affecting the overall temperature of the environment.


Moreover, there are some grow lights that contain ballasts. Ballast discharges heat because it converts the incoming current to the level needed to power the bulb.


Sometimes, the critical factor to consider is what type of species you're planning to grow, as some plants are able to better handle heat than others.

If they're heat-tolerant plants, then it must be a fantastic choice. Succulents and umbrella plants generally flourish better in the heat than others.

Also, heat from grow lights plays its ultimate significance when climates are extremely colder, and plants are showing signs of cold stress. At this point, heat from these sources contributes to maintaining a favorable and stable temperature.

Additionally, through heat, plants are able to increase their rate of transpiration and create microclimates favorable for certain plants.

All in all,  the presence of heat in a growing space facilitates plants to perform their most crucial task of photosynthesis, which is the root cause of their survival.


Basics of Indoor Gardening and Climate Control

Overview Of Essential Environmental Factors For Indoor Plant Growth (Light, Temperature, Humidity, Etc.).

Light, in conjunction with other environmental factors such as temperature, humidity, and water, are important variables that affect plant growth and development, and any of these factors in improper proportions would hinder the growth process.


For instance, plants without enough amount of water would soon make them die. Similarly, inadequate lighting would make them pale and yellow. So, keeping all the parameters in ideal conditions is what makes indoor planting efforts successful.



Light is primarily the most crucial factor that dictates how a plant grows and enlarges.  It is the light that allows plants to process their most fundamental task of photosynthesis. A change in light intensity influences the manufacture of plant food, stem length, leaf color, and flowering.


Sometimes, this intensity of light is the reason for plants to trigger the flowering process. Also, the duration and light wavelength play a key role in bringing the best outcomes in plants. Those light-loving plants thrive well under too much light, while few of the plants show signs of stress under heavy light exposure.


Similarly, adjusting the optimal spectral distribution of light at each growth stage influences the growth output. During the vegetative stage, a light rich in the blue wavelength is well-suited for plants, and red light works wonders in the flowering phase.


It’s crucial to understand each plant's nature in order to work favorably. Because Good lighting can be a reason to have healthy foliage, leading to an increase in harvest.


In this regard, LEDs are a wise choice to integrate into the grow room because they offer customizable spectrum and intensity adjustment, making your cultivation efforts much more manageable.



Temperature is one crucial parameter influencing the crop quality, agricultural productivity, and growth hormones of plants, including photosynthesis, transpiration, respiration, germination, and flowering.


It’s the temperature that allows the transitioning of one growth stage to another. Orchids, for instance, require a 10 -15° drop in temperature to trigger blooming, and tomatoes require a warmer room temperature to germinate.


Most indoor plants are sensitive to temperature fluctuations. An under and over temperature would prevent them from growing. There's no perfect 'temperature' guideline that can be applied to every plant, as different varieties may respond at different temperatures.


You need to understand each plant species in order to adjust the right temperature for their consistent growth pattern.


In general, foliage house plants grow best between 70 and 80 degrees Fahrenheit during the day and from 60 to 68 degrees Fahrenheit at night.


Similarly, if you want to grow tropical or subtropical plants indoors, your indoor temperatures should be normal and shouldn't reach hot and cold extremes. Too much heat from the light source, cold air from a door or window, or exposure to frigid air when a new plant is brought indoors from the store in winter can result in leaf and flower drop. If the plant is exposed to freezing temperatures, the foliage will collapse and turn black.




Humidity is measured as the amount of moisture in the air. This element greatly affects plant growth, with low humidity causing plants to dry out and high humidity causing problems with disease and mold.


This humidity level also impacts the health and appearance of leaves. A high humidity level makes leaves prone to fungal infections, while less humidity promotes leaf browning or desiccation.


If you notice that the humidity level inside the grow room during the vegetative period is below 60% and below 40% in the flowering stage, then immediately arrange a humidifier to let the plants cool.

Different Types of Grow Lights and Their Heat Emission

While you choose to integrate grow lights for your houseplant, a list of options would make you puzzle about which type is best for your home garden. It makes sense to get one that provides less harm to the plants and is efficient enough to go smoothly throughout the growing period.


But a quick rundown below would give you more clarity. So, give this section a read before you shop for the lights.

Light Emitting Diode, or LED

The most talked about term in the lighting industry, and now the most preferred horticulture light source is LED. There are many justified reasons that put LED in the first place. Their ability to produce maximum energy for plants, i.e., 80% of electrical energy into usable light while keeping the electricity cost lower, is a mind-blowing feature.


On top of it, with LEDs, you're at peace of mind about getting your plants under extremely hot temperatures. This is because LEDs don’t emit heat in the form of infrared radiation; they're generally cooler to the touch.

The Heat Emission Characteristics Of LED

It's pretty accurate that LEDs are far safer to use for plants due to their less heat-generating characteristics. But when you read about LEDs precisely, many scientists observe that due to the energy efficiency of LEDs, also defined as luminous efficacy (lumens per watt), it significantly decreases with increases in input power.


As the input power of the LED rises, the higher heat generation from the LED chip leads to a high junction temperature. This phenomenon would accelerate the luminous decay rate and shift the lighting color's wavelength more quickly.


Luckily, the LED built-in heat sinks and fans can effectively dissipate this heat. These grow lights work perfectly for heat-sensitive plants.


Fluorescent Lights

Fluorescent lights are low-pressure bulbs charged with mercury vapor in which a glow discharge occurs, producing short-wave ultraviolet radiation. This is then converted into visible radiation by a phosphor deposited on the inner walls of the lamp.


This is a very common type of grow light that fits in smaller indoor gardens. They generate optimal lighting for new young plants while starting seeds, growing seedlings, or growing those that typically thrive under cooler temperatures. They contain a broad spectrum of light, generally in the blue and red wavelengths.


Due to the fact that fluorescent lamps discharge less heat, they’re a suitable option for plants that naturally tend to grow in less warm environments.

The Heat Emission Characteristics Of Fluorescent

Compact Fluorescent bulbs or linear tubes both discharge 30% of their energy as heat, which clearly means they're more energy efficient and are generally cooler in nature than regular light fixtures.


What it entails here is they’re about 70% more energy efficient compared to an incandescent bulb because they don’t use resistance to emit light.


Growers can make the most of these lights when they're particularly interested in saving electricity costs and when finding low-light options for plants.


The typical luminous efficacy of fluorescent lighting systems is 50–100 lumens per watt, much better than that of an incandescent bulb, which may only be 16 lumens per watt.


You can expect as much as 30% of the heat discharge from fluorescent lamps to reach 50-60F for a 60-watt bulb.


High-Pressure Sodium Lights: HPS


HPS is another grow light category that is particularly built to discharge high-intensity light, mostly favored during the flowering stages of plant development. They usually contain a red and orange spectrum around 600-700nm, which is beneficial when plants are turning to bloom.


The Heat Emission Characteristics Of HPS

As the name implies, the high-intensity lamp generates a significant amount of heat as a by-product during indoor planting operations. Based on the efficiency performance, around 80% of the energy emitted by HPS comes out as heat, which is way too much.


Know that much of this energy emitted by HPS lights is in the form of infrared light (above 800 nanometers). However, this light isn't used by plants and only contributes to warming up the leaves and everything else under the light.


However, many growers put it in a safe zone when compared with metal halide, but they are not far off.


HPS lamps get extremely hot to the touch and can be dangerous if placed too close to plants, even up to the extent that they can catch fire. If you grow with HPS, heat will always be a major issue.


Impacts of Heat on Plant Health

Heat isn’t always harmful; in fact, plants require a certain amount of heat to thrive. Just like us, plants need energy to grow, and some of that energy comes from the heat.


Do you know the secret to tomato plants' raw, juicy deliciousness? Yes, it’s the plant's exposure to heat.


However, when excessive or prolonged heat coincides with plants, you’ll see that it can have detrimental effects on plants' health. Many occurring problems include heat stress, wilting, and reduced growth rates.


This calls for a thorough understanding of the heat impact on plants so that you’re able to work with grow lights more efficiently.


  1. Stunted Growth:Intense heat temperatures inside the grow room have been associated with stunted plant growth. Growers have observed that High heat absorbs water and nutrients from the roots, resulting in a reduced growth pattern. This is due to the fact that excessive heat can disturb the plant metabolism and physiological processes, causing irreversible damage to the overall development.


  1. Disrupt Photosynthesis:Plants subjected to high heat stress significantly disrupt the essential photosynthesis mechanism, which is a big negative point to hold. When the heat reaches beyond a threshold, plants fail to produce the required energy, which is vital for their growth.


  1. Plant Cellular Damage.Heat can be dangerous to the extent that it can cause intense damage to the integrity of the cell membranes. Obviously, when plant cells can’t control the movement of water, nutrients, and other vital substances, it could result in cellular dehydration, cell death, and nutrient imbalances.


  1. Pest Infestations and Diseases:Heat makes plants fall victim to deadly pests and diseases. The heat-causing vulnerability of plants invites all sorts of pests, such as aphids, mites, and fungi, further compromising plant productivity.


  1. Flower Drop or Early Blooming Transition:A noticeable effect of heat on plants is evident when crops start to bloom early before their harvested season. Some species, such as ornamental plants, have reported losing their buds and blossoms or failing to flower.

Managing Heat in Your Indoor Garden

Now that you’ve read about the adverse effects of too much heat, the need to keep the heat at an ambient level becomes significant.


With the below troubleshooting strategies, plant heat no longer remains an issue. Especially the full spectrum LED manufacturer would take it so easy due to their heat managing light fixture.

Strategies For Balancing Light And Heat For Optimal Plant Growth.

In indoor plant growing endeavors, the problematic aspect for growers is managing the harmful effects of light exposure and an excess amount of heat accumulation. However, if you opt for a few of the valuable strategies, you can tackle the concern to a great extent.

  1. Choose A Wise Light Source:

The First practical initiative is to equip your grow setup with a dimmable LED grow lights. This would substantially reduce your concern for high light intensity. LEDs prove to be plant-friendly light chambers as they tend to discharge less heat, and with their dimmable switches, you can alter the light ratio per the plant's requirement, saving unwanted electricity.

  1. Manage the Photoperiod

Adjusting the plant photoperiod (the light duration ) is another effective measure to eradicate the harmfulness of light and heat. Making the right light schedule during specific times of the day helps promote plant growth without excessive heat.

  1. Ensure Adequate Light Distribution

Ensuring proper light coverage would be a great help in an effort to give plants an optimal environment. By this, we mean the proper placement of light sources and their adequate distribution over the plants. This dramatically prevents uneven heating and shading and offers more uniformity and consistent light coverage.

  1. Use of Reflective Materials

In order to redirect light onto the lower foliage, reflective surfaces or materials are handy to optimize the light distribution. This equipment eradicates the need to install intense light sources, significantly reducing heat buildup.

  1. Temperature Monitoring

It's true that every plant has temperature preferences, so in an indoor setup where you’re in charge of the environmental variables, you can install cooling fixtures to prevent overheating. At this point, you can also choose a light source with built-in heat sinks that act as a crucial component to dissipate heat and efficiently contribute to temperature control.

  1. Installing Proper Heat Extraction Fan System

Making sure that you've enough heat extraction fans in indoor grow rooms is a wise decision to bring more fresh air inside and excess heat outside. By turning them on, you’re able to distribute temperature more evenly throughout the crop and break up microclimates around all leaves for better light exchange, in addition to helping control powdery mildew.


  1. Using Shade Curtains During Hotter Days

Among all other powerful strategies, one effective way to manage heat and light is using shade curtains during the high light, high temperatures months. These curtains typically reduce light exposure by 30% to 50% and help tackle the light brightness, especially for plants exposed to natural light through windows or doors.



Grow lights for plants is a sustainable choice for many growers when sunlight is inadequate or absent in many regions. But with grow lights comes a great risk of heat management. Different types of light devices have varying degrees of heat-generating properties, so adjusting to maintain the optimal condition becomes challenging.


Several strategies can be adopted to minimize the heat stresses and can be worked to make this heat in the best interest of plants.


In recent years, LED has been the most favorable light source and is more of a next-generation lighting technology. This widespread adoption is due to the cooling characteristics of LEDs that have attracted more and more attention.  


Although it’s not that LEDs don’t produce heat at all, the heat-sinking feature dissipates heat and thus produces the most suitable light energy for plants.






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