How to Cool A Grow Tent?

Indoor gardens involve creating a makeshift environment which tends to replicate the conventional outdoor environment and the best way to go about this, is by using a grow tent.

The jackpot with using a grow tent is that you get the chance to control the light schedule, light intensity, humidity, and even temperature and thus manipulate them to your own advantage which enables you to cultivate bigger and better plants as it gives you complete control of the growing environment. Grow tents are not exactly conventional or natural but they are fantastically versatile.

A lot of people are faced with the dilemma of how to cool a grow tent, especially during hot summer periods. As a matter of fact in some cases it gets so bad that some indoor growers decide to halt growing completely during hot summer days and wait till the weather is generally more favorable naturally before they resume planting their crops. 

And the reason for this occurrence is either because they have previously been victims of very bad outcome due to extreme heat or they have heard people tell them how hard it is to cool a grow tent during hot summer days.

How to Cool A Grow Tent?

Beating the heat is a dilemma most indoor growers face but surprisingly this problem can be solved by a couple of ways the most effective of which would be discussed below;

Air Conditioning

Air conditioning is particularly important because there isn’t anything that combats heat during the hot period as much as an air conditioner so keeping an air conditioner can help to combat the heat from nature as well as heat that builds up from lights, pumps and other electronics.

Before you purchase an air-conditioner for your grow room, be sure to consider the size of your grow room and seasonal outdoor temperature as this would affect the air conditioners efficacy.

Carbon dioxide

Carbon dioxide

As easy as this sounds, using carbon dioxide can be very tricky as it is really only helpful when the normal optimal temperature of a grow tent has already been exceeded.

From basic biology, we all know that carbon dioxide is pretty much important for plant photosynthesis so the catch is that when you increase the level of carbon dioxide in your grow tent the level spikes and helps plants to perform more efficiently and thus maintaining normal function even in a hotter condition.

Air-cooled lighting

The mechanism of action of this is pretty much easy, all it does is that it uses an extraction fan to pass air over the lamps and then removes warm air from your grow tent using aluminum or acoustic/insulated ducting.

The insulated ducting is better than the aluminum due to the fact that it does more cooling than the aluminum. So in summary, the air-cooled lights possess a glass bottom which creates an air fitted channel. Cool air is released through this channels and over your lamps to eradicate heat.

Water cooled lighting

This is way more efficient than the air-cooled mechanism discussed above and the reason is that water cooled light surprisingly reduces the need for an air-conditioning system. If you adopt this method in cooling your grow tent, you would use a reservoir and water pump and subject to the size of the reservoir you are using, you may also need to get water chillers.

Room insulation

A well-insulated room generally helps regulate the temperature in your grow tent as it is not subject to the outdoor environmental conditions.

In some cases, lighting might be the major cause of dangerous heat spikes but in most cases, it could merely be due to poor insulation especially if you have a grow room located directly under a hot roof. 

Note that below ground insulation is way cooler because the soil provides a natural insulation. So, to cool your grow tent, you might want to consider insulating the room.

Promote good air circulation

It is important to ensure that the air in the grow tent circulates optimally in other to avoid hot spots, this would also help to ensure that your plants grow healthy with their stems and leaves growing way stronger.

Be sure to invest in oscillating fans or get a lot of fans that would alternate directions because getting the leaves to move in various direction is important as this replicates their natural motion in outdoors environment this further concludes that it is important to have a fan in every corner of your grow tent.

Lighting is very important

You know how fast an enclosed place can get hot in a few minutes and you know having grow-lights and fixtures in your grow tent is unavoidable, so what you can do is learn how to maximize it in a way that less heat would be generated.

You can go about this by choosing the right light and this boils down to opting for lights that emits the least amount of heat such as LED or simply use air or water cooled reflectors.

Install a light mover

Installing a light mover is one of the simplest ways of spreading heat uniformly in your grow tent to avoid having hotspots and this helps to better manage light resources and also reduce the need for additional lights and further minimize the heat those light would further generate.

So, to cool down your grow tent, simply install the light mover which would assist in circulating the heat in the room to all parts instead of having it concentrated in on a spot.

Running lights at night

Generally, the temperature is much cooler in evenings and at night compared to daytime temperature so it would be way more advisable to use hot grow-lights when the temperature is remarkably lower.

The off-peak times are a good time as most electrical utilities charge lower rates during off-peak times so when you run the light in your grow tent at night as opposed to running them during the day, you save both energy and money at the same time.  

Running lights at night is a good way of keeping the temperature down so during the hot summer period you can suck in the cool night air.

Improve your ventilation system

Another way of cooling your grow tent is by improving the ventilation system in the tent. It is indeed a notorious fact that air exchange is a fantastic way to control high humidity and finding an automated system that helps you lower and increases fan speed automatically when appropriate. So if you want to cool down your grow tent, you should improve on the ventilation.

Reservoir chillers

Reservoir chillers are a must have for anybody that intends to have an indoor garden because having control over the temperature is important as extremely hot temperature invariably affects the health and growth of the plants.

Buying a chiller for your reservoir will help to eradicate the problem of high temperature and by implication, bringing your tent to your desired temperature level swiftly.

Ice bottle

It would interest you to know that something as little as an ice bottle can help cool grow tent drastically. All you have to do, for example, is to place a 2-litre frozen bottle of water into your nutrient tank this works like magic, as it helps to swiftly cool down your reservoir.

However, this mode of cooling should be an alternative or the last option because where it doesn’t regulate the temperature then you would require a chiller.

Led lights

grow lights

These are particularly advisable during hot periods as it emits little heat but it cannot be used all year round because during the winter your grow tent would suffer as the heat in the grow room would definitely not be sufficient enough.

So do your research on LED lighting and try to have it handy during the summer period and be prepared to remove them when the weather becomes cold.

Employ evaporative cooler evaporative coolers or swamp coolers

These use the same principle as air conditioners to reduce the ambient temperature in the environment. A swamp cooler has a fan which propels hot air through a water-moistened medium it then evaporates the water and this leads to a resultant drop in the temperature. Misters also work similarly by producing little water droplets which evaporate almost instantly. They all inadvertently increase the humidity of the grow tent.


To sum up, everything that has been stated, the problem of how to cool a grow tent is one that is faced all over the year especially during the hot period and its effects can be quite devastating because it could drastically slow down growth, increase moisture loss, hamper plant growth and affect seed germination.

The importance of keeping the temperature inside your grow tent within optimal temperature cannot be overemphasized. Having excess heat in your grow tent does a lot of harm to your plants for example without a doubt, excess heat can kill cannabis, especially during the flowering phase.

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