How to lower temperature in grow tent: top 9 methods

The most difficult part of growing cannabis indoors is probably maintaining a perfect growing environment in your growing space.

It’s also the most crucial element. It’s understandable why growers ask me so many questions about how to lower their grow tent temperature

There are various doable actions you may do to reduce grow tent temperature. Changing from an HPS (High-Pressure Sodium) to an LED grow light, relocating the tent to a cooler part of your home, and checking that the grow tent fan is blowing air out the window rather than into the room where the tent is situated are a few examples.

There are other steps you can take to lower your grow tent temperature, which I’ll list below.

How can you cool a grow tent?

You might have a significant or minor heat issue, depending on the environment where you live, the sort of grow lights you’re using, and several other variables.

The techniques for cooling your grow tent that is outlined below can all be effective. But unless you only have a small amount of surplus heat to cope with, the majority won’t be sufficient on their own.

If the issue is more serious, you’ll need to combine numerous approaches. It gets trickier if you are concerned about being discovered by a helicopter using thermal imaging.

That being said, combining numerous techniques is always going to be the most beneficial and that is definitely what I advocate, even if you don’t have a serious heat issue.

Signs your weed plants need to cool down

Wilted leaves

If the plant starts to grow too hot, the water in the leaves will evaporate. Lack of water will cause the leaves to droop since water in plant cells helps provide the leaves firmness. Lack of irrigation can also result in drooping leaves and generate the same symptoms.

Curled-up crispy leaf tips

The leaves may become brittle and dry. The leaf tips and edges will start to curl up as a result. This typically indicates that the temperature has recently increased.

Method 1: relocate your grow tent

Think about shifting your grow tent to the house’s coolest room. For instance, if you have central air conditioning, it can be near some air vents in your basement. You should think about putting it next to open windows.

Your grow tent will be able to benefit from cool seasonal climates if it is next to open windows.

Additionally, it will make it simple for you to run your ducting directly out the window from within the tent.

Occasionally, all your tent needs are some movement of the stagnant air. Most households have one or two tiny fans laying around.

You could also simply get a clip-on fan while you’re here. They will aid in the distribution of heat and are inexpensive and barely occupy any space.

Relocating your growing area. Because heat rises, a two-story house or one with a basement will have significantly different growing temperatures throughout your grow room.

Simply by relocating my grow tent from the upstairs to the basement, I can lower its temperature by nearly 10 degrees.

Method 2: route grow tent ducting out the window

By just blowing air into the room where your grow tent is located, you could be defeating the function of the inline fan. Because the air being drawn back into your grow tent to counteract the negative air pressure produced by your inline fan is the air in the room where your tent is placed.

Take your ducting, or purchase more if required, and direct it out a neighboring window.

This makes it simpler to maintain your grow tent temps because the air being drawn back into your tent won’t mix with the hot tent air.

The temperature inside your grow tent will inevitably be a few degrees higher than the outside temperature due to natural causes.

Method 3: turn on your air conditioner

Cool off the space where your grow tent is placed, it will keep your grow tent cool. The air inside your grow tent can be cooled down quickly by doing this.

The simplest approach to achieve this is to keep the room cool by buying a portable air conditioner or opening a window during the colder months.

Consider putting the portable air conditioner inside the grow tent if that doesn’t work.

When the inline fan blows out hot air and creates negative air pressure in your grow tent, the cool fresh air in this area is what is drawn back into your tent. The lower screen windows of your grow tent allow cooler air to enter.

You must make sure that there is a proper air exchange from your tent, eliminating the hot air and bringing in the cool air, to cool the tent.

Keep in mind that if the temperature inside your tent is 85 °F and the outside air entering it is just 80 °F, there isn’t enough of a temperature difference for the tent to cool.

To eliminate plant-related odors, a typical ventilation system contains an exhaust fan, ducting, and a carbon filter.

The air exchange is carried out by the exhaust fan, often known as an inline fan. It draws in fresh air from outside your grow room and lets warm air out that would otherwise be trapped inside your tent.

Method 4: add CO2 to your grow tent

This simple-to-use CO2 bag won’t lower the temperature in your grow tent, but it works just as well.

Is high temperature bad for Cannabis plants? Cannabis plants can survive greater temperatures when there is an increase in CO2 levels.

How much additional heat can cannabis endure when the CO2 level is high? 85 or 86 °F would be the ideal temperature for growing. Normally, without CO2, the temperature range is between 70 and 80 °F.

Method 5: take an ice box (with ice or dry ice)

This approach will call for some imagination, but if you’re up for the challenge, it takes work. Because you won’t need to refill the ice as frequently while using dry ice, maintenance will be significantly reduced.

In addition to cooling down grow tent temperatures, using dry ice also creates CO2, which enables plants to flourish at higher temperatures (between 85 and 90 °F)!

What you’ll need:

• Chest to hold the ice
• Ice or dry ice
• Oscillating fan

How can you assemble it?

Simply putting your ice in a box or chest and directing an oscillating fan at it can accomplish this. If you’re feeling particularly inventive, you might decide to seal the chest, make a hole on each side, put a fan in one, and let the air out the other.

Note on dry ice/CO2

Fresh air contains about 400 ppm of CO2. Most gardeners agree that plant yields are greatly boosted when CO2 levels are between 1,200 and 2,000 ppm.

Remember that CO2 is harmful to people and that, despite being generally harmless, levels between 1,000 and 2,000 ppm can make people feel sleepy.

Toxic levels begin at 2,000 ppm or above. Don’t let the level get any higher than that.

Because CO2 is heavier than air, an oscillating fan should be running to move it throughout the tent. You may take the ice box out of your grow tent when the lights are off because plants only use CO2 during photosynthesis.

Using regular salt ice might want to manufacture salt ice if you decide against using dry ice. This can be accomplished by freezing salt water rather than ordinary water. The salt prolongs the freezing time of the ice.

Method 6: make sure your inline fan is strong enough

Your grow tent’s inline fan is a fantastic initial step for eliminating heat from the space.

As a general rule, your grow tent’s inline fan needs to replace the air once each minute. You must also consider employing a carbon filter and the reduced fan power caused by ducting bends.

Method 7: switch from HPS / HID grow lights to LED grow lights

High-power grow lights and HPS grow lights generate high temperatures than LED grow lights when it comes to regulating the temperature in a grow tent.

Try switching to LED grow lights if you are frequently dealing with excessive temps while using HID bulbs. Just be sure to keep the LED grow lights away from your plants.

Additionally, try leaving your lights on at night and turning them off during the day during the summer because operating the lights during the day generates excess heat that is bad for your plants.

Your grow space will become warmer as a result of any sort of light.

It will be required to have an exhaust fan to keep the grow space from being overheated.

Using a Mini Inline Fan to cool fans that are also referred to as exhaust or ventilation fans will aid in circulating the air within your grow space.

Method 8: place your grow light drivers outside your grow tent

Some LED grow lights, such as the Mars Hydro TS-3000 (4×4 ft) and TSL-2000 (2×4 ft) versions, feature replaceable drivers if you decide to transition from HPS to LED grow lights. Growers that struggle to lower grow tent temperatures would greatly benefit from this.

Method 9: relocate hydroponic equipment outside your grow tent

Pumps, filtration, reservoir chillers, and other electronic devices that may be moved with the help of an extension cord or long pipes might be used if you’re hydroponically cultivating plants. To aid in lowering the temperature within the grow tent, think about transferring as much of it outside.

FAQs

Conclusion

As you can see, there isn’t just one ideal way to lower the tent temperature. For you, one approach might be simpler or more efficient than the other. Your grow tent’s interior temperature control requires both scientific knowledge and artistic skill.

My personal preference would be the dry ice method if the simpler techniques don’t work for you because the CO2 that is produced as a byproduct of dry ice enables plants to survive at greater temperatures while the ice itself will function to cool the grow tent.

Also Read About Easy Ways to Control Temperature in a Grow Tent