How to Cool A Grow Tent? – 10 Actionable Ways to Take

How do the months of June to August feel to you? HOT, we guess. And given a chance, we run under the ACs or at least the fans to cool ourselves down.

If that’s the case with us, why not the plants? We’re talking about a grow tent specifically, to whom you’re pretending to be ‘Mother Nature’ from every point of view.

Therefore, if you’re worried about how to cool a grow tent that’s running unusually hot, that’s very legit to do that. And by the end of this article, we’re going to put an end to that little worry of yours.

Here we have 10 ways to keep the temperature of a grow tent under control. If you’re a grower, we bet you can’t stop scrolling till the very end.

Let’s start-

What Turns a Grow Tent Hot?

Before learning to cool it down, we need to know what’s the culprits behind the sudden heat buildup in a grow room. In this section, we’re going to call each of the possible reasons by their names. Let’s see-

  • If the ventilation goes wrong, this traps the heat produced in the tent within the tent. The obvious consequence? Yeah, its heat trapped in the tent itself and raising the temperature.
  • Too much hot surroundings might be a possible reason why the tent HVAC system isn’t making it up to the par. The hotter it’s out there, the more work the cooling system has to do. Otherwise, the temp and heat will go way up.
  • In case you have too many sources of heat within the grow tent territory and not enough cooling agents to neutralize them, then that’s another possible reason.
  • A lack of proper insulation around the tent exterior can be another possible reason that we would like to address. And that’s quite likely to happen in summer climate zones.

Acknowledged them all? Let’s head to the possible ways through which we can sort them out for a good cause.

Ways to Cool A Grow Tent- Without Products

In this first part of the solutions, we will talk about improvisations that you can do to cool down a grow tent. These will not associate buying any products or any sort of expenses at all. It will be all about improvisations, optimizations, and adjustment.

Let’s check out-

Way 1: Get the Best Out of the Ventilation Scopes

Each of the grow tent kits available in the market comes up with vent holes through which you can put carbon filters, ducting in and out, and anything relevant.

On that note, you have to make sure that these venting opportunities are at their best use. And that will eventually put the heat buildup and raise in temperature down. Also, ensuring proper airflow is another concern that can be driven from here.

There are a few specific tips that can be done to improve the ventilation with the given resource you already have in your hands. Here you go-

  • Re-locate the positions of the clip-on or stand fans within the grow room. Also, you can adjust the speeds if they offer to do so.
  • Relocate the position of the input duct opening to the coolest place available nearby. Done so, cool air will enter into the tent and provide a significant drop in the temperature inside.
  • Consider sealing the vent holes properly, if they are not done so already.

Way 2: Diminish the Heat Sources as much as Possible

Using products that cool the air is the straightforward idea of cooling down a grow tent. But if we think otherwise, this can also be done by diminishing the heat sources within a reasonable limit. And that works no less good as well.

While naming heat sources, there are a definite few in a grow system. Let’s check out the list-

  • The lights (#1 source of heat).
  • Space heaters.
  • Motor-driven devices.
  • Soil that contains heat within them.

Now, let’s talk about the grow lights first, as they are the main sources to diminish here.

Firstly, lights have to be kept within a fair distance from the plants. Next on, you can use air-cooled light hoods instead of regular ones. Cause, these hoods take care of the hot air that the light creates and don’t let it enter the grow room.

Other than these two, there are some minor facts that you need to check out. The first one is to keep the lights on during the night time. Also, you have to use automatic controllers to keep the lights off while not needed. And finally, the obvious advice is to use lights that generate low heat whatsoever.

With the other sources of heat, you can go with similar approaches that we advised to do with lights. It’s all about keeping the heat production within a tolerable limit, as you know.

Way 3: Optimize the Ducting

Now, this is a thing that many growers often overlook and end up with an unexpectedly hot growth environment. And that’s the overly done bending within the ducting.

A clear-cut calculation is- for every 90 degrees turn within the duct, the fan has to work 5% harder than what it has to do usually. So, the more turns and bends your ducting has, the less efficient the fans will be. Result? Poor air transfer and rise in the heat level.

So, make sure that your ducting is with the least amount of turning and bending while they are from some other place to your grow room. And that’ works from both intake and exhaust ducting.

In case you need it, you can use more ducting and increase the length of it. But doing so, you need to ensure that you’ve kept the bending within the minimum level.

Way 4: Avoid Low Humidity in the Grow Tent

If you’ve studied it, you might have the firm idea that there is a direct connection between humidity and temperature. Especially, when it’s about a confined area like a grow tent, the relation is more obvious.

The rule of thumb is- the lower the humidity is the higher the temperature will be. And vice versa.

So, somehow, if the humidity is below the par, then that might promote heat and temperature buildup within the grow room. The exact value of ideal humidity is 60% for young grow plants, and 40% for plants that are grown up.

In case the humidity within the grow tent is lower than that, raising them up will be helpful for both the plants and the heat situation in the grow tent.

Way 5: Reposition the Grow Tent As Per the Exterior

As long as the heat issues are regarded, it’s quite important that where within the house the grow tent is located. Usually, growers like to keep them in isolated places like the garage, the cabinets or so. But in case you’re not one of them, here are some tips for you.

Don’t locate the grow tent to the south-facing wall of your house. This is likely to induce how to surround the grow tent.

The next advice is not to keep the grow tent under the topmost roof. This brings on the heat of the sun via the adjacent air and makes the tent to inhale hot air.

The best solution is, however, to keep them deep inside your home or garage, which doesn’t have any roof or wall exposed to the sunlight. Rest assured; you can take care of the ventilation anyhow.

Ways to Cool A Grow Tent – With Products

Way 1: Use Mini Air Conditioner for Grow Room

It’s an obvious fact that air conditioners are supposed to keep the temperature of space down. And for a confined and contoured space like a grow tent, this works better than any other scenario.

Therefore, if you want to spend after cooling down your tent, mini ac units are the one that you should do it after.

However, based on the size of your grow space, there can be two possible options in here-

  1. Mini AC units(portable).
  2. Split AC (non-portable).

Mini AC units are less powerful, but powerful enough for small grow tents like 4×4, 4×5, 5×5, 6×6, 8×8, and even 10×10. They usually come up with a decent BTU, and they are portable. So, while not used in the tent, it can be used otherwise.

Our Recommended Mini AC Units

On the other hand, we have split ACs that work wonders if the grow space is a bit large. They are efficient, self-controlling, and promise long durability. But as you can guess, they cost quite some bucks.

Our Recommended Split AC Units

Way 2: Use Fans

As you are already with a grow tent setup, we presume that you have probably occupied the fan(s) in it. But as the situation indicates that these fans are not cooling the tent enough, we think there can be a scope of improvisation.

We are talking about replacing the old fans with new and more effective ones. Finding the right size and type of fan is always effective to keep the temperature healthy for your grow plants.

While we are talking about fans, we are talking about two types of them-

  1. Inline fans: Fans that are in the ducting, taking care of the air intake and air exhaust.
  2. Oscillating fans: They are openly attached to the grow tent wall or stood on the floor to take care of the inner air circulation of the grow tent.

Therefore, find the right size of both of these types, and locate them smartly. Locating the fans is also important because if placed in the wrong point, this can just circulate the old, hot air within the air instead of promoting fresh and cool air.

Our Recommended Inline Fans

Our Recommended Oscillating Fans

Air King Clip Fan, 6 inch, White
Air King Clip Fan, 6 inch, White
6-inch commercial-grade 2-speed fan with spring-loaded clip-on design; Permanently lubricated 1/300-horsepower motor; polypropylene blade

Way 3: Use Water Chillers

If you find ac units too expensive for the volume of indoor gardening you’re up to, there is a finer and more affordable out there. And it’s called the water chillers.

Water chillers are electric devices that absorb the moist vapors and leave the cool and chilled ones. There are two types of them- the water-cooled chillers and the air-cooled chillers. The later one is cheaper but happens to be less effective for grow tents larger than 4×4.

However, our hands-on recommendation would go with using water-based chillers. These devices come with a water reservoir to contain the water, and an evaporating system to take down the temperature of the surrounding.

On a side note, these devices serve another purpose, and that is- they keep the humidity high. As you have seen before, low humidity is one potential reason behind grows tent heating. And with a water-based chiller, this chance is well within the minimum level.

However, for the best-case scenario, we recommend using a good humidifier for handling the humidity issue whatsoever. 

Our Recommended Water Base Chillers

JBJ Aquarium Arctica Titanium Chiller, 1/10 HP
  • The most quietest chiller on the market
  • Highly efficient condenser; use less energy
  • Corrosion resistant; contains safe ozone friendly...

Way 4: Control the Climate

As long as heat control of a grow tent is concerned, significant progress can be made by controlling the environmental items from your end. By that, we’re addressing items like-

  1. Grow light.
  2. Inline fans.
  3. Oscillating fans.
  4. Air Conditioner.
  5. Humidifier.
  6. Dehumidifier.
  7. Any other electric HVAC devices.

If you can apply some preset controlling commands about when they should turn on, and when to keep turned off, this will be pretty effective. Especially, to keep the unwanted invasion of heat, this works very well.

On top of that, there are a handful of health benefits to the plants if you put a firm control on the grow tent environment like this.

The controllers are available in various forms in the market. There are solo controllers, and there are 360-degree environmental controllers.

Here is a list of our recommended product from both of the categories-

bayite Temperature Controller BTC201 10A Dual Pre-Wired Digital Outlet Thermostat Plug, 2 Stage...
bayite Temperature Controller BTC201 10A Dual Pre-Wired Digital Outlet Thermostat Plug, 2 Stage...
Simplified Design---Plug and play, easy to set. Support °C/°F display
Inkbird ITC-308 Temperature Controller with IHC-200 Humidity Controller
Inkbird ITC-308 Temperature Controller with IHC-200 Humidity Controller
【Buzzer Alarm】High and low temperature/humidity alarms support custom adjust.; 【Reliable】Inkbird is the first one to offer pre-wired temp/humidity controllers.
Titan Controls Day/Night Carbon Dioxide (CO2) Monitor & Controller w/ Photocell, 120V - Atlas 3
Titan Controls Day/Night Carbon Dioxide (CO2) Monitor & Controller w/ Photocell, 120V - Atlas 3
Controls and monitors CO2; CO2 enrichment or CO2 exhaust features; ETL listed product to UL standard 917
Titan Controls 4-Light Controller w/ Relay Trigger Cord, 240V - Helios 4
Titan Controls 4-Light Controller w/ Relay Trigger Cord, 240V - Helios 4
This controller will run four (4) HID lights at 240 volts; 120 volt accessory timed outlet to activate in-line fans to cool your lamps

Way 5: Use An Ice Box

Do you know what’s even more affordable than a water-based chiller? Yes, you’ve read it right, it’s the icebox.

Just like the name sounds, it’s a box of ice. Instead of a box, you can also use a bucket and turn that into a DIY icebox. These are not items that you can find commercially. But in case you’re interested, you can make one using simple DIY steps.

Closing Words

Hey, we’re at the end. Pat your back, as you’ve just completed a 2000+ words article on how to cool a grow tent through a handful of options.

Our last advice would be to match-make between the situation of your grow tent and find the best suitable solution from the list. In case it takes some money to be invested, don’t hesitate. Because, in the end, it’s going to reward you with a handful of healthy, quantitative yields.

Let’s keep our hopes high. Happy growing!