Danny as been writing about air purifiers for 10+ years. He is a major fan of home technology, which makes him the perfect person to test and evaluate products for HouseFresh
Any keen horticulturist will tell you growing crops, vegetables, or plants is no easy task. To see the fruits of your labor requires the right environment, knowledge, and of course, hard work. When it comes to growing specialist plants, such as cannabis, this is certainly no exception. In fact, these particular plants are as tricky as it gets to grow, requiring very specific conditions if to be successful.
Whether you’re a budding botanist or novice, keen to shore up your own supply, many home-growers achieve great results by utilizing a grow room. This controlled space allows you to master the temperature and light required to deliver a successful crop. Yet one factor often overlooked is humidity.
For a high-yielding crop, getting the humidity right in your grow room is essential. If there’s too little humidity, the plant will lose more water during the photosynthesis process than it can absorb through its roots, stunting its growth and quality. Whereas if there is too much moisture in the air, you pave the way for pests, mold, and mildew that can quickly result in the downfall of your crop or kill your plants entirely.
Due to grow rooms being warm, sealed spaces often located in cooler surroundings such as the basement or garage, you’re far more likely to encounter issues with high humidity. In order to nip this in the bud, investing in a quality dehumidifier will enable you to further control the conditions in your grow room and ensure your plant will remain happy and healthy.
To save your green fingers scrolling through endless reviews, we’ve researched the 8 best dehumidifiers to use in your grow room. We’ve included a range of machines, suitable for varying sized spaces and across different budgets to include something for everyone. We also utilized Consumer Reports and analyzed product reviews through Fakespot to ensure genuine users were satisfied with the results their dehumidifier provides.
Last update on 2023-09-17 / Affiliate links / Images from Amazon Product Advertising API
1. Honeywell Energy Star 50-Pint Dehumidifier TP70WK
Honeywell adds to its small appliance portfolio the 50-pint Energy Star certified dehumidifier. This unit operates at temperatures between 41 degrees and 90 degrees Fahrenheit, with humidity control between 30% and 90% relative. This makes the model perfect for grow rooms from the planting stage with higher humidity to flowering and late-stage growth, with lower humidity.
The unit is relatively compact, measuring 12.4 x 15.75 x 25.4 inches, minimizing its footprint among your plants. The entire unit weighs only 42.9 lbs and has built-in rolling casters and a heavy-duty handle capable of supporting 150 lbs. You’ll easily be able to place this unit exactly where you need it.
Despite its small size, it boasts a massive 182 CFM air movement while running on high. This allows it to service a room of up to 4,000 square feet and remove an impressive 50 pints of water from the air per day. The unit has an internal 2.1-gallon condensate reservoir, and also comes with a built-in continuous drain feature and includes a 3 ft drain line so that you can immediately use the feature.
The controls include a 24-hour timer to delay the start or set an automatic shutoff, sleep mode to reduce noise, and an automatic humidistat to control humidity at your desired level. The unit also consumes 759 W per hour, so you would expect to consume about 18 kWh per day if you leave it running continuously.
- Tank Size: 2.1 gallons
- Room Size Suitability: 4,000 sq. ft
- Weight: 42.9 lbs
- Special Features: Swiveling handle and splash guards on the condensate reservoir to minimize spilling
What we love
- The automatic shut-off when the condensate reservoir is full prevents overflowing
- There’s an indicator light for when the filter needs cleaning
- The large condensate reservoir allows for longer operation before requiring emptying
- It has an automatic restart after a power interruption with the last-used settings
We don't like this as much
- The shorter power cable and condensate drain limit placement options
- The continuous drain is gravity fed, so it only works with floor drains
2. TCL 20 Pint Portable Dehumidifier
The TCL 20-Pint portable dehumidifier operates perfectly in a medium-sized space that doesn’t get overly humid. This unit measures 10.63 x 14.57 x 19.29 inches, so it will easily fit most medium-sized grow rooms. It has molded handles on the sides, rolling casters, and is only 34.6 lbs, so it’s small enough to easily move around.
The unit operates effectively in temperatures down to 41 degrees Fahrenheit, with a humidity range between 35% and 80% relative. You can select your ideal humidity in 5% increments.
The controls are beautifully simple with two fan speeds, simple up and down humidity level selectors, and a timer for automatic start and stop with up to 24-hour delay. It also has three pre-programmed modes: continuous, basement (set to 45% relative humidity), and bedroom (set to 55% relative humidity). It also has an indicator for a full condensate reservoir and a dirty filter.
The unit will draw up to 20 pints of water out of the air per day, servicing up to 1,500 square feet. It has an internal reservoir that will hold up to 7.4 pints (just shy of a gallon). It also has a standard garden hose connection for a continuous drain option.
Don’t worry about safety, as this unit comes packed with options. It has an automatic shutoff for a full reservoir. You also have an automatic restart after a power interruption to the previous settings. The automatic defrost feature protects the coil from damage from freezing.
- Tank Size: 7.4 pints
- Room Size Suitability: 1,500 sq. ft
- Weight: 34.6 lbs
- Special Features: The unit has a child lock to prevent accidental setting changes
What we love
- It is Energy Star Certified, using a mere 300 to 400 Watts, depending on the setting
- The small footprint makes it easy to fit just about anywhere in your grow room
- The condensate reservoir has a lid to help prevent spills during emptying
- There is a water level window to allow you to quickly see the level in the reservoir
We don't like this as much
- You have to supply your own drain hose for the continuous drain
- We’d like to see the addition of a condensate pump in order to provide more options for placement
3. SEAVON Dehumidifiers for Home
The SEAVON breaks the mold for light dehumidification in small spaces. This compact model measures only 18 x 10 x 7.6 inches. There is a molded handle at the top of the back, making it easy to lift and set up. It’s light enough to move wherever it’s needed, weighing in at a mere 4.7 lbs. It will service up to 510 square feet, and remove up to 750 ml, or 1.6 pints, of moisture daily.
The solid base ensures the unit won’t roll off any elevated surfaces. This unit operates most effectively at temperatures between 59 degrees and 104 degrees Fahrenheit, making it a great addition for controlling humidity in your grow room.
The SEAVON model uses a Peltier rather than the standard compressor. This keeps the noise down to a very subtle 35dB, using a mere 78 Watts per hour, making it exceptionally energy efficient. If run continuously, this translates into 1.87 kWh daily.
The controls operate from the remote with three simple buttons: power, mode select, and light. The remote control will operate up to 30 feet away. There are two modes, normal and quiet. The water tank LED lights illuminate for monitoring the reservoir level. There is also a single button on the unit to allow you to turn it on and off without the remote.
You’re protected from condensate overflow with the automatic full reservoir shut off. Given there is no refrigerant and compressor, the unit has no need for a defrost function.
- Tank Size: 0.5 gallon
- Room Size Suitability: 510 sq. ft
- Weight: 4.7 lbs
- Special Features: The unit has a remote control to easily turn the unit on and off
What we love
- The unit operates very quietly with a mere 39dB rating
- It has a reservoir level indicator to allow to easily monitor when it needs emptying
- The unit is exceptionally light, making it perfect to sit on a table or shelf in your grow room
- Simple on/off controls make it perfect for small grow rooms or greenhouses
We don't like this as much
- The unit only operates effectively down to 59 degrees, which is not as ideal for areas with very cold weather
- There is no air filter, allowing more contaminants to collect inside the unit and add strain
4. hOmeLabs Energy Star Dehumidifier
It can be especially difficult to control humidity levels in large rooms, with the sheer volume of air they contain. To be effective, you must have the capability of moving large volumes, plus be able to quickly remove moisture. The hOmeLabs 3,000 square foot dehumidifier presents the perfect solution.
This model is small, measuring only 15.2 x 10.2 x 19.7 inches, and weighing only 40 lbs. Despite the compact size, it moves between 165 and 188 CFM, depending on the setting. This means it can move up to 270,000 cubic feet of air each day if left fun continuously. With the help of other fans in your grow room, this should be enough to effectively move the air and control the humidity in a 3,000 square foot space.
There are molded handles on the sides at the top and rolling casters on the bottom. Both of these help manage the weight while putting the unit in place in your grow room.
It will remove up to 35 pints of moisture from the air each day, draining it into the onboard 1.6-gallon condensate reservoir. If you prefer a continuous drain option, there’s a connection on the back for a standard garden hose.
Simple controls match the simple setup, with a single button comfort level, which sets the humidity based on the ambient air temperature. If you prefer more specific control, you can set your desired humidity level, and set the fan speed to either normal or turbo. You also have the option for a 24-hour timer to delay the start or shut the unit down automatically.
- Tank Size: 1.6 gallons
- Room Size Suitability: 3,000 sq. ft
- Weight: 40 lbs
- Special Features: Offers a comfort setting that automatically sets the relative humidity level based on ambient temperature
What we love
- Energy Star certified, indicating this as an efficient compressor-style dehumidifier
- Indicator light to remind you to wash the air filter
- Includes automatic defrost to protect against frozen coils
- Automatically restarts with the same settings after a power interruption
We don't like this as much
- We’d love to see an automatic shut off feature when the target humidity level is achieved
- It does not include a pump, so it must sit over the floor drain for the continuous option
5. Frigidaire 22-Pint Dehumidifier
Frigidaire is one of the most recognizable brands for home appliances. When you purchase something from their brand, you can trust it to get the job done without any fuss. The 22-pint dehumidifier upholds this brand’s commitment to excellence.
This unit weighs in at 36.2 lbs, and measures only 11.34 x 15.5 x 19.78 inches, making it easy to fit into just about any small grow room. It includes an integrated side and top handle and has rolling casters to make it easy to set up and move.
The unit comes with a 2-gallon condensate reservoir, complete with a splash guard and handle to make emptying easy. It also has a continuous drain plug on the back of the unit to connect a hose to allow for use without having to remember to empty the reservoir.
It has electronic controls with a three-speed fan setting, and a control to set your desired humidity level. Not only that, but it also offers a time to delay the start or set to automatically turn the unit off.
The compressor shuts down when the bucket reaches its capacity to prevent water damage from overflowing. It also has an indicator to alert you to when the condensate reservoir is full. If you prefer not to wait for the indicator, the reservoir also has a window to allow you to easily see the level.
The included washable filter helps ensure pollen and other contaminants remain out of your unit. It tracks the hours of operation and alerts you to when the filter should be washed. There’s a button on the control panel to reset the timer.
- Tank Size: 2 gallons
- Room Size Suitability: 300 sq. ft
- Weight: 36.32 lbs
- Special Features: The unit has a bracket on the back to store the power cable when not in use
What we love
- The condensate drain reservoir has a carry handle and splash guard to help prevent spilling while emptying
- It has quiet operation, with a maximum sound rating of 49dB
- The unit has three different fan speeds, compared to the standard two
- It automatically restarts after a power interruption with the previous settings
We don't like this as much
- You must provide a garden hose before using the continuous drain feature
- The built-in humidistat only reads in increments of 5%, making for a large swing between automatic cycles
6. GE Portable Dehumidifier
Another brand you are likely familiar with among household electronics and appliances is GE. Serving the consumer market since 1892, people have trusted these products for everything from light bulbs to refrigerators and more. This dehumidifier is perfect for medium size grow rooms, easily tucking into a corner or under a shelf.
The unit has a smaller footprint, measuring 21.85 x 13.7 inches, but only standing 10.63 inches tall. It also has a 6-foot power cable, giving more flexibility to where you place the unit in relation to the power outlet. It also has rolling casters and molded handles on the sides to help make moving it easier. With the Energy Star certification, it uses about 400 Watts per hour, or roughly 9 kWh per day if left to run continuously.
It has a 1.1-gallon internal condensate reservoir so that you don’t have to constantly empty the tank. If you need your unit to run longer between emptying, it has a continual condensate drain with a standard garden hose connection. There’s an alarm that will sound for 10 seconds when the reservoir is full and automatically shut down to prevent an overflow.
The controls include humidity level selection and three fan speed options. There’s also a Smart Dry feature, which controls the fan speed by comparing the set humidity with the actual relative humidity.
To keep the unit running effectively, it has an indicator to notify you when it’s time to clean the air filter. There’s also an automatic defrost feature to help protect the unit against a frozen condensing coil.
- Tank Size: 1.1 gallons
- Room Size Suitability: 1,000 sq. ft
- Weight: 34 lbs
- Special Features: The Smart mode automatically adjusts the fan speed so that it runs faster when the grow room’s humidity rises
What we love
- The unit runs quietly, with a maximum sound rating of 50 dB
- A longer 6-foot power cable provides more flexibility for placement
- The large reservoir has a built-in handle and cover to help make emptying mess-free
- The 24-hour timer allows you to delay start or automatically shut the unit off
We don't like this as much
- The continuous drain is gravity fed, so it only works with a short hose directly behind the unit
- The condensate reservoir is on the smaller side for the capacity if you’re using it in an overly humid climate
7. Whirlpool 50 Pint Portable Dehumidifier with Built-In Pump
When you hear the Whirlpool brand, you probably think of quality kitchen and laundry appliances. It should come as no surprise that this dehumidifier is one of the best-rated for small spaces. This unit can remove up to a massive 50 pints of moisture every day from a room of up to 650 square feet.
The unit is compact, with a footprint of 12 x 15 inches. It is taller than most at 25 inches and weighs 43.74 lbs. There are molded handles on the side and rolling casters to help move it more easily.
To control the unit, you can select your ideal humidity and one of three fan speeds. A 24-hour timer automates turning the unit on and off when desired. There are also continuous, basement, and bedroom pre-programmed modes. There’s a child lock to prevent unintentional adjustments while it’s running.
You can use the internal 2.2-gallon condensate reservoir, or attach a standard garden hose to the unit for continuous draining. Unlike many other models, this one has an integrated pump to push the condensate up to 16 feet above the unit, accounting for the extra weight. You’ll be able to easily empty the reservoir with the integrated handle and spill guard.
You won’t have to worry about overflowing the reservoir, with the automatic shutoff and indicator for a full tank. Not only that, but you’ll see when it’s time to clean the washable filter with the indicator, and the coils are protected with the automatic defrost function.
- Tank Size: 2.2 gallons
- Room Size Suitability: 650 sq. ft
- Weight: 43.74 lbs
- Special Features: The integrated pump makes the continual drain feature more effective when the drain isn’t directly behind the unit
What we love
- There’s an automatic restart after a power interruption to restore previous settings
- It uses a mere 260 watts, less than many other comparable models
- The unit operates down to 41 degrees Fahrenheit, making it great for spring in your grow room
- The integrated pump allows for nearly uninterrupted operation in your grow room
We don't like this as much
- The short 4.9 ft power cable does provide some limitations on where you can set it up
- Once you turn the pump on, it runs continuously until the unit shuts off
8. AIRPLUS 30 Pint Dehumidifier
If your grow room is also a place where you hang and taste your creations, you’ll want a dehumidifier that’s a little more stylish. AIRPLUS rises to the occasion with the sleek and curvy design of the 30-pint dehumidifier.
This unit is inconspicuous, occupying a mere 7 x 11.7 inches, and standing 19.6 inches tall. Your company won’t notice its operation, with a volume of less than 45dB.
It weighs in at a mere 23 lbs, much lighter than many other models. There is an integrated handle at the top of the back to help lift the unit. It also has integrated rolling casters on the bottom to assist with moving it around.
The controls offer mode selection, humidity adjustment, and a 24-hour timer for delayed operation or automatic shutdown. The available modes include standard, or continuous, drying for rapid dehumidification, sleep for quieter operation, and raining which sets an automatic 45% relative humidity.
You have the option of using the internal 3-pint condensate reservoir or using the included continuous drain feature. There is an automatic shutoff to prevent overflowing when the reservoir is full, and an indicator light on the control panel. The reservoir is conveniently located in the middle of the back of the unit and is small enough so that you can easily remove it to empty the water.
The unit will control the humidity in your grow room without breaking the bank. If left to run continuously for a month, it uses a mere 138 kWh. It operates optimally between 40% and 80% relative humidity.
- Tank Size: 3 pints
- Room Size Suitability: 500 sq. ft
- Weight: 23 lbs
- Special Features: Offers an anion function, which emits negative ions to remove dust and bacteria from the air
What we love
- The sleek design is much more attractive than many other models
- Powerful enough to effectively control the humidity of a small grow room
- The included washable filter helps extend the life of your unit
- The negative ion function helps further improve the quality of your air quality
We don't like this as much
- There is no automatic restart after a power interruption, so you’ll have to reset the previous settings
- The included silicone drain line is short, limiting where you can place the model and use that feature
FAQs about Dehumidifiers For a Grow Room
Should a dehumidifier run constantly? Generally, a dehumidifier should not run constantly. Rather, you should run it when the relative humidity exceeds 50% relative and shut it off when it reaches your set humidity level. Many models have a built-in humidistat to automatically control cycling the unit on and off. Most models have a continuous mode to keep the dehumidifier running. This is really helpful when you first start the unit or when your space is exceptionally damp. However, continuing to run your unit on this setting adds tremendous strain to the system, uses more energy, and doesn’t offer an equal benefit. Are dehumidifiers important for indoor grow rooms? Humidity is exceptionally important for the life of plants. Too little moisture, and many plants wilt. Conversely, too much will prevent proper circulation, inhibiting the plant’s ability to evaporate water and draw in more nutrients from the soil. The ideal humidity will depend on your plants and their stage of growth. For most plants, you’ll want a higher relative humidity between 70% and 75% in the germination and seedling stage. Vegging plants should have a relative humidity of 50% to 70%, while flowering plants need 40% to 50%. Be careful not to dry out your grow room too much, or you’ll deal with as many problems as when it's too damp. What size dehumidifier do I need for a grow room? There are many dehumidifier sizes, and ways to determine which one you need. Size is generally measured in how much moisture the unit can remove from the air, combined with the size room it can service. The size of room a unit can service is in large part determined by the amount of air volume it draws in. The amount of moisture it can remove is determined by the size of the condensing coils and compressor. The other factor to consider is how many plants you have in your grow room, and how much moisture they’ll require. You can always err on the side of going too large for your dehumidifier, so it will not run as long. If you think you can get away with a 30-pint unit, you may want to get the 50-pint option to make sure it’ll serve your needs during the most humid seasons. Which Dehumidifier is best for you? The right humidity in your grow room can be the difference between thriving plants and wilting messes. The first thing to look for in a quality grow room dehumidifier is the ability to adjust the relative humidity based on the growth stage. When first planting and during the seedling stage, you’ll want about 70% relative humidity. Once your plants are established, you’ll want to drop your humidity to between 30% and 50% relative, depending on the type of plants. Beyond the adjustable humidity, think about where in your grow room you’ll place the unit. Most dehumidifiers pull a substantial amount of energy, so you’ll want it close to the power outlet to avoid running an extension cord. Consider the length of the power cord on your unit, along with the length of the continuous drain line. Finally, consider where you’ll want to drain your unit, either using the internal condensate reservoir or the continuous drain option. If you’re using the continuous drain, think about the location of the drain compared to your unit. If you’re going to drain into a sink or the drain is a little distance away, be sure to consider a model with a condensate pump. Given these considerations, here are our top picks of smaller, mid-range, and larger rooms.- Budget/Smaller Grow Rooms - The SEAVON Dehumidifier for Home
- Mid-range Rooms - GE Portable 35-Pint Dehumidifier
- Larger Rooms - Honeywell Energy Star 50-pint Dehumidifier