Quick verdict
A pre-wired humidity controller: plug a humidifier into one outlet and a dehumidifier or fan into the other, set your target, and it switches them to hold the room between 5 and 99 percent relative humidity with stated accuracy of 3 percent. It calibrates, shows the reading on a bright display and needs no wiring. For mushroom growers, propagators and grow tents it is the standard affordable humidistat, and Inkbird has a long track record with it.
Strengths
- Dual outlets: one humidify, one dehumidify, switched automatically
- Plug and play; no wiring
- Range 5 to 99 percent RH, stated accuracy plus or minus 3 percent
- Calibration adjustment and clear digital display
- Long-established model with wide owner base
Weaknesses
- Outlets share a limited total load; check your appliance wattage
- Sensor probe cable is short for large greenhouses
- No app or data logging on this model
The overall YardToolLab Score is out of 100. Section scores are out of 10.
Humidity on Autopilot
Seedlings, cuttings and mushrooms want humidity held in a band, and a humidifier running unchecked overshoots as surely as none at all undershoots. A humidistat switches it. Inkbird’s IHC200 is a pre-wired plug-in controller with two outlets, one for a humidifier and one for a dehumidifier or exhaust fan, that holds any target between 5 and 99 percent relative humidity to a stated 3 percent and switches between the two automatically.
This review is based on Inkbird’s specifications and on how plug-in humidity controllers are used in greenhouses and grow rooms generally. We have not run this controller ourselves.
Setup
Plug the controller into the wall, the humidifier into the humidify outlet and, if you use one, a dehumidifier or fan into the other. Hang the sensor at crop height out of the humidifier’s plume. Set the target and the differential, the band either side of the target before switching, and leave it. Three buttons and a bright display make this a five-minute job, which is why the IHC200 has become the default for hobby growers.
Accuracy and Calibration
Plus or minus 3 percent is good for an affordable sensor and sufficient for propagation and fruiting chambers. The calibration function lets you offset the reading against a known reference, such as a saturated salt test at 75 percent, so a drifting sensor can be corrected rather than replaced.
Dual Control
Most owners use the humidify side only. In a damp basement or a sealed tent where humidity climbs on its own, the second outlet runs a dehumidifier or exhaust fan to pull it back down, and the controller alternates as needed. That makes it a complete climate control for humidity in one small box.
Limits
The two outlets share a rated load; check it against a large dehumidifier before plugging in. The probe cable suits a tent or a small greenhouse, not a long polytunnel. There is no app or logging; Inkbird’s Wi-Fi models add those at higher cost.
Who Should Buy It
- Mushroom growers running fruiting chambers and monotubs.
- Propagators keeping cuttings and seedlings humid.
- Grow tent and small greenhouse owners with a humidifier to control.
Common Owner Complaints
Short sensor leads and confusion over the differential setting. Read the manual’s example once and it is clear.
Alternatives to Consider
Inkbird’s IHC200-WIFI adds app control and logging. The AC Infinity Controller 69 manages fans, humidity and temperature together. A simple timer is the crude alternative for humidifiers.
Verdict
For holding humidity in a tent, propagation case or mushroom chamber, the IHC200 is the reliable plug-and-play choice at a fair price, with a long record behind it. Place the sensor well, calibrate once and it will quietly do the job for years.
Full specifications
Inkbird IHC200 Pre-Wired Digital Humidity Controller with Dual Outlets FAQs
Set a target humidity and a differential. Below target the humidifier outlet switches on; above it the dehumidifier or exhaust fan outlet switches on. Most users run only one side.
Ultrasonic humidifiers, small dehumidifiers and exhaust fans within the rated load of the controller. Check the wattage on the unit against your appliance.
At plant or mushroom height, away from the direct plume of the humidifier so it reads room humidity rather than fog. Extend with care; the probe cable is modest.
Three percent is adequate for fruiting chambers, which want roughly 85 to 95 percent. Calibrate against a salt test for best results.
