What Are Dehumidifiers And How Do You Use Them to Grow Cannabis?
3 min

What Are Dehumidifiers And How Do You Use Them To Grow Cannabis?

3 min

Maintaining proper humidity in your growing space can be quite the task, especially if you live in a more tropical climate. If you're constantly fending off airborne moisture while you grow, we would suggest getting a dehumidifier for your grow space. Pulling water directly out of the air, these things will fight off bud rot and mildew with ease.

Even amongst expert cannabis growers, balancing humidity within a grow room can be a complicated task. After all, you have a bunch of plants growing together in a compact space. Even if you have a window open and a fan running to circulate air, it can get too humid before you know it. From there, you could potentially have to deal with problems like mildew and bud rot, making harvest day more of a headache than a celebration.

Considering the risks, don’t you wish you could just pull the water right out of the air? Well, you may not be able to do that yourself, but a dehumidifier can complete the task with just the push of a button. We’ll teach you how these devices work, and show you how to use them in your pursuit of balanced humidity.

What Are Dehumidifiers? How Do They Work?

What Are Dehumidifiers?

As they aren’t too common, we don’t blame you if you’re unfamiliar with these devices. Simply enough, a dehumidifier is an upright-standing electronic device outfitted with special vents and fans. It uses these to suck in water from the air and collect it in a removable internal bucket. In this sense, as you’d expect, it’s the functional opposite of a humidifier.

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Also, while they vary in size, you can expect yours to be around one metre tall on average. Many petite varieties are available, though, so you won’t be limited by space. There are no controls or actions necessary beyond turning it on and altering the humidity settings. Just let it run, dump out the water once the internal bucket fills up, and relax!

Benefits of Dehumidifiers

Benefits of Dehumidifiers

As simple as they are, dehumidifiers offer some fantastic benefits to grow rooms in distress.

  • Good for Overall Health of Grow Room

For starters, dehumidifiers generally improve the environmental conditions of the grow room. This makes issues like mildew and bud rot far less common than usual.

  • Natural Protection Against Mould, Mildew

Those improvements also mean you don’t have to use chemicals to protect your crops. This not only preserves the quality of your plants, but saves you loads of time and money you’d otherwise spend on those solutions.

  • Save Time on Ventilation

Since humidity is the prime factor behind ventilating your grow space, you don’t have to spend nearly as much time dealing with that process. In turn, you can focus on maintaining other aspects of your grow.

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Ventilation In The Cannabis Grow Space

  • Stable Conditions

In turn, cutting down on ventilation means your grow room temperature will stay stable, as this process can cause dramatic swings between warmth and cold. This decrease in fluctuation means you'll also save a lot, perhaps up to 50%, on energy costs.

Home Dehumidifier vs Cannabis Dehumidifier

Home Dehumidifier vs Cannabis Dehumidifier

Now, you might be looking at some random dehumidifier online thinking you’re ready to go. However, you need to consider several important distinctions between home dehumidifiers and those designed for growing cannabis.


For starters, you’ll find that home dehumidifiers tend to be quite small. While you would think this might be fine for compact growing operations, it likely won’t work as well as you want it to. A cannabis dehumidifier, however, will tower above its home-specific counterpart. As they’re meant to service sizable spaces full of plants, and suck up a proportional amount of water, they need to be heftier.


More important than the size, however, is the amount of space the humidifier is designed to cover. Given that home dehumidifiers are meant to treat smaller spaces in a house, they won’t have an awfully far range. Their range is even smaller when compared to cannabis dehumidifiers, which are designed to cover the entirety of a standard-size indoor growing room.

Special Features for Growing

Lastly, it’s worth noting that cannabis-specific dehumidifiers will come outfitted with extra features that come in handy during growing. For instance, if there’s already a lot of noise in the room, you could get one that features a compressor to keep things quiet. Busy growers might also be interested in options with automatic shut-off features, allowing them to go in and empty out the water on their own time.

How to Set Up a Dehumidifier in the Cannabis Growing Room

How to Set Up a Dehumidifier in the Cannabis Growing Room

Now that you know the specific types of dehumidifiers to consider, you’ll want to figure out how and where to situate it in your grow room. With that information in mind, you’ll be able to pick the one best suited to your needs.

1. Calculating Coverage

To start, break out your tape measure and figure out the area measurements of your growing space. Armed with those measurements, you can make notes of specific dehumidifiers suited to those room dimensions.

2. Optimal Placement

There’s an art to placing the dehumidifier correctly, too, as it won’t work the same in whatever area it’s placed in. Ideally, you want there to be a decent amount of open space all around the dehumidifier. Having it too close to your plants could dry them out, and having it too far could make it useless.

3. Room Shape and Air Flow

The last factor to consider is the actual shape of your room, and the way air flows through it in turn. Certain areas of the room, for instance, may have less air flow than others, and may need to be dehumidified more to boot.

Dehumidifiers in the Drying Room

Dehumidifiers in the Cannabis Drying Room

Dehumidifying doesn’t have to stop when you’re done growing, either. Seeing as buds are under an elevated threat of mould during the drying process, it could be wise to have a dehumidifier in the room throughout the process. In turn, keeping it in there means you might be done with drying after just one week (instead of the typical two). Then, after it's done drying your bud, your dehumidifier is ready to care for your next round of plants!

Steven Voser
Steven Voser
Steven Voser is an independent cannabis journalist with over 6 years of experience writing about all things weed; how to grow it, how best to enjoy it, and the booming industry and murky legal landscape surrounding it.
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