In a grow tent or room, the plants are the humidifier: they transpire most of the water you feed them. That moisture has to go somewhere, or humidity climbs, VPD (vapor pressure deficit) drops, and mold and bud rot become a risk in late flower. Ventilation helps when outside air is drier, but a dehumidifier gives you control regardless of the weather.
Size by water, not floor area. A rough starting point is to estimate how much water you add per day: most of it ends up in the air, so your dehumidifier needs to remove at least that much in your room's conditions.
| Model | Rated capacity | Control | Tent or room size |
|---|---|---|---|
| AC Infinity Hydrone 7 | Listing shows 2 L (unclear if per day) | 10 levels; humidity and VPD via AC Infinity controller | 4 to 6 plants |
| AC Infinity Hydrone 5 | 2 L/day (listing) | 10 levels; smart controller compatible | 2 to 3 plants |
| Midea Cube 50 | 49.67 pints/day (DOE, 65F) | Built-in humidistat and app | Small rooms, large tents with ducting |
| Quest Hi-E Dry 195 | 195 pints/day (80F, 60% RH) | Built-in humidistat | Grow rooms |
| AlorAir Storm 80X | 80 pints/day (AHAM); 170 saturation | Built-in humidistat | Rooms and greenhouses |
Sources: Amazon listings, ENERGY STAR record (Midea), Quest spec sheet.
Grow room dehumidifiers compared
| Pick | Capacity | Coverage | Pump | Noise | ENERGY STAR | Price tier | |
|---|---|---|---|---|---|---|---|
| AC Infinity dehumidifier review: Hydrone 7 AC Infinity Hydrone 7 | See notes | Grow tents for 4 to 6 plants; Amazon lists 64 sq ft | Not stated | Not published | Not stated | $$$ | Check price |
| Best for small tents AC Infinity Hydrone 5 | See notes | Grow tents for 2 to 3 plants; Amazon lists 16 sq ft | Not stated | Not published | Not stated | $$ | Check price |
| Best value for small rooms Midea Cube 50 (pump) | 50 pints/day (DOE) | Up to 4,500 sq ft (maker claim) | Yes | Maker: as low as 42 dB(A). RTINGS measured 54.3 dBA (low fan) to 56.2 dBA (high fan) | Yes | $$$ | Check price |
| Best for grow rooms Quest Hi-E Dry 195 | 195 pints/day (AHAM 80F) | Not stated | Not stated | Not published | Not stated | $$$$$ | Check price |
| Best greenhouse dehumidifier AlorAir Storm 80X | 80 pints/day (AHAM 80F) | Up to 2,100 sq ft (Amazon listing) | Yes | Not published | Not stated | $$$$$ | Check price |
AC Infinity dehumidifier review: Hydrone 7
AC Infinity HYDRONE 7 Smart Plant Dehumidifier
Best for: grow tents already using AC Infinity controllers.
The AC Infinity Hydrone 7 is built for grow tents with 4 to 6 plants. Its listing describes 10 drying levels with instant on-off response, humidity and VPD control through AC Infinity's controllers and app, and an exhaust port that ducts dry air into the tent, with an optional intake for a closed loop. That integration is its main selling point if you already run AC Infinity fans and controllers. AC Infinity does not publish a clear pints-per-day figure on the listing we checked, so you cannot compare its capacity directly with a standard dehumidifier.
| Model number | AC-DHT7 |
|---|---|
| Type | Plant dehumidifier for grow tents (technology not stated by maker) |
| Coverage | Grow tents for 4 to 6 plants; Amazon lists 64 sq ft |
| Built-in pump | Not stated |
| Wi-Fi / app | Not stated |
| ENERGY STAR | Not stated |
| Noise | Not published |
| Control | 10 drying levels; humidity and VPD control with AC Infinity controllers and app |
| Capacity | Amazon's detail table lists 2 liters without saying whether that is per day or the tank |
| Ducting | Exhaust port can duct dry air into a tent; optional intake for a closed loop |
| Price tier | Mid (about $200 to $400) |
Pros
- Designed for tents
- VPD automation with AC Infinity controllers
- Ductable
Cons
- Capacity not clearly published
Spec sources (checked 2026-11-12): Amazon listing B0G7MB9LHJ (Model Number AC-DHT7).
Best for small tents
AC Infinity HYDRONE 5 Precision Plant Dehumidifier
The Hydrone 5 is the smaller version for 2 to 3 plants, with a listed 2 liters per day and the same 10-level control and smart-controller compatibility.
| Model number | AC-DHT5 |
|---|---|
| Type | Plant dehumidifier for grow tents (technology not stated by maker) |
| Coverage | Grow tents for 2 to 3 plants; Amazon lists 16 sq ft |
| Built-in pump | Not stated |
| Wi-Fi / app | Not stated |
| ENERGY STAR | Not stated |
| Noise | Not published |
| Capacity | 2 liters per day (Amazon detail table) |
| Control | 10 drying levels; works with AC Infinity smart controllers |
| Price tier | Value (about $100 to $200) |
Pros
- Small footprint
- Controller integration
Cons
- Small capacity
Spec sources (checked 2026-11-12): Amazon listing B0GFPS5PZD (Model Number AC-DHT5).
Best value for small rooms
Midea Cube 50 Pint Smart Dehumidifier with Pump
For a small grow room, or outside a large tent with ducting, a standard 50 pint unit is the most capacity per dollar. The Midea Cube 50 is certified at 49.67 pints a day, has a pump to send water to a drain and an app to watch humidity. It has no VPD control, so set it by humidity.
Heads up: Midea sells several SKUs (MAD50PS1QWT, gray MAD50PS1QGR, MAD50S1QWT without pump). Check the exact model number.
| Model number | MAD50PS1QWT |
|---|---|
| Type | Compressor (portable) |
| Capacity (current DOE test, 65F) | 50 pints/day |
| Coverage | Up to 4,500 sq ft (maker claim) |
| Built-in pump | Yes |
| Wi-Fi / app | Yes |
| ENERGY STAR | Yes |
| Noise | Maker: as low as 42 dB(A). RTINGS measured 54.3 dBA (low fan) to 56.2 dBA (high fan) |
| Bucket / capacity | Expandable bucket; listed as 3x more water capacity than a standard bucket |
| Humidity setting range | 35% to 85% |
| Rated power input | 480 W (Canadian MAD50PS1QGRC spec sheet) |
| Drain options | Bucket, gravity hose, or built-in pump that lifts water to a sink or window |
| Pump lift | Up to 16.4 ft vertical per Midea's spec sheet (a Midea support answer on Home Depot says 14 ft) |
| ENERGY STAR test data | 49.67 pints/day, IEF 2.01 L/kWh, about 515 kWh/yr (record for MAD50PS1QWT-A) |
| Price tier | Mid (about $200 to $400) |
Pros
- High capacity per dollar
- Pump
- App
Cons
- No VPD control
- Adds heat to the room
Spec sources (checked 2026-11-11): Midea US product page (MAD50PS1QGR, 4,500 sq ft, pump); Midea Canada spec sheet MAD50PS1QGRC; Home Depot listing (42 dB(A), ENERGY STAR, 3X water capacity); RTINGS review MAD50PS1QWT (measured noise, efficiency); ENERGY STAR certified product record (MAD50PS1QWT-A).
Best for grow rooms
Quest Hi-E Dry 195 Portable Dehumidifier
The Quest Hi-E Dry 195 is a grow room standard: 195 pints a day at 80F and 60% RH, 610 CFM, on a 115 V circuit. Its spec sheet also lists 160 pints at 70F and 60% RH, which is closer to real flowering-room conditions.
Heads up: Sold mainly through hydroponics and HVAC suppliers; the Amazon link searches for it.
| Model number | Hi-E Dry 195 (4046400 A2L version) |
|---|---|
| Type | Commercial compressor (high capacity) |
| Capacity (AHAM test, 80F, 60% RH) | 195 pints/day |
| Coverage | Not stated by maker |
| Built-in pump | Not stated |
| Wi-Fi / app | Not stated |
| ENERGY STAR | Not stated |
| Noise | Not published |
| Capacity at other conditions | 160 pints at 70F, 60% RH; 120 pints at 70F, 50% RH (older spec sheet) |
| Efficiency | 6.1 pints/kWh (A2L version spec sheet); older version 4.9 to 5.4 |
| Power | 115 V, about 12 A (A2L version) |
| Airflow | 610 CFM |
| Price tier | Pro (about $900 and up) |
Pros
- High capacity
- 115 V
- Published capacity at several conditions
Cons
- About 12 A draw
- Pro price tier
Spec sources (checked 2026-11-12): Quest Hi-E Dry 195 spec sheet (A2L, 4046400); Quest Climate: Hi-E Dry 195.
Best greenhouse dehumidifier
AlorAir Storm 80X Commercial Dehumidifier with Pump
A greenhouse dehumidifier has to cope with cool nights, when humidity spikes. The AlorAir Storm 80X is a rugged commercial unit with auto defrost, a pump and a rotomolded case, rated at 80 pints AHAM and 170 at saturation.
| Model number | Storm 80X |
|---|---|
| Type | Commercial LGR (low grain refrigerant) |
| Capacity (AHAM test, 80F, 60% RH) | 80 pints/day |
| Coverage | Up to 2,100 sq ft (Amazon listing) |
| Built-in pump | Yes |
| Wi-Fi / app | No |
| ENERGY STAR | Not stated |
| Noise | Not published |
| Capacity at saturation (90F, 90% RH) | 170 pints/day |
| Airflow | 200 CFM |
| Efficiency | 2.28 L/kWh (maker figure on the listing) |
| Power | 607 W |
| Pump | 19.6 ft hose |
| Housing | Rotomolded polyethylene |
| Weight | 63.9 lb |
| Price tier | Pro (about $900 and up) |
Pros
- Rugged
- Auto defrost
- Pump
Cons
- Not designed around VPD control
Spec sources (checked 2026-11-12): Amazon listing B0DH3G92CX (Model Number Storm 80X).
Humidity by growth stage
Targets vary by crop and grower, but industry guides agree on a downward trend from seedlings to late flower. These ranges come from grow-equipment makers and hydroponics guides, not university research, so use them as starting points:
| Stage | Typical RH range | Typical VPD range |
|---|---|---|
| Seedlings and clones | About 65% to 80% | About 0.4 to 0.8 kPa |
| Vegetative | About 55% to 70% | About 0.8 to 1.2 kPa |
| Flowering | About 40% to 60% | About 1.0 to 1.5 kPa |
| Late flower | Toward the low end of flowering | Toward the high end |
Sources: Quest Climate VPD guide; AC Infinity VPD chart; hydroponics retailer guides. AC Infinity gives wider VPD bands (for example 0.8 to 1.8 kPa in flower).
Sizing for grow tents
| Space | Suggested approach |
|---|---|
| 2x2 to 3x3 ft tent | Small tent unit (Hydrone 5 class) or good exhaust ventilation |
| 4x4 ft tent | Hydrone 7 class, or a 22 to 35 pint unit outside the tent with ducting |
| 5x5 ft or larger tent, or a small room | 50 pint unit (Midea Cube 50 class) |
| Dedicated grow room | Commercial unit sized to the daily water load (Quest class) |
What size dehumidifier for a grow room? Start from the water you add each day. If you water 5 gallons a day, that is 40 pints, and most of it will be transpired, so you need a unit that removes at least that much in your room's temperature and humidity, plus margin for lights-off spikes.
Can a dehumidifier go inside a grow tent?
Small tent units like the Hydrone are designed to go in or duct into the tent. A standard portable dehumidifier takes up a lot of space and adds heat, so in smaller tents it usually sits outside, either drying the room the tent pulls air from or ducted in. In a large tent, putting it inside works if you can handle the extra heat and drain the water out.
Frequently asked questions
What size dehumidifier for a grow room?
What humidity for flowering?
Can a dehumidifier go inside a grow tent?
Sources
- Quest Climate: Vapor pressure deficit by growth stage
- AC Infinity: VPD chart, what it is and how to use it
- Quest Hi-E Dry 195 spec sheet (A2L)
- ENERGY STAR Certified Dehumidifiers dataset (data.energystar.gov)