Humidity Controllers

A humidity controller switches your dehumidifier, humidifier or fan on the reading rather than on a timer. It is the difference between a room that holds its target and one that swings around it all day.

Why a timer is not enough

Humidity is not predictable on a schedule. It spikes when the lights go off and the air cools, it climbs as the canopy fills out, and it changes with the weather outside. A dehumidifier on a timer runs when it is not needed and sits idle when it is. A humidistat runs it when the number says so.

Targets through the cycle

The dangerous moment is lights-off in late flower: air cools, relative humidity climbs sharply, and moisture condenses inside dense flowers. That is where bud rot starts, and it is exactly the moment a timer-driven dehumidifier is likely to be off.

What to look for

• A deadband or hysteresis setting so the unit does not short-cycle on and off around the setpoint.
• Combined temperature and humidity if you are also controlling a heater or fan – one controller, one sensor position.
• Sensor placement at canopy height, away from the direct path of the dehumidifier outlet, or you are regulating on a false reading.
• Adequate socket rating for the appliance you are switching.

Related

See humidity control for dehumidifiers, humidifiers, hygrometers and grow room monitoring.

Why buy from The Hydro Bros?

We are a hydroponics shop in Croydon and putting kit on a sensor instead of a timer is the cheapest real upgrade most rooms can make. Discreet UK and European delivery, and excellent customer reviews on Trustpilot.