Description
Description
The Fantech MDEH1 is a 2‑wire, low‑voltage mechanical dehumidistat designed for simple humidity control in ventilation systems such as HRVs and ERVs. It uses a rotary dial that allows the user to set a desired indoor humidity level, activating connected equipment whenever the indoor humidity rises above the selected point. Because it is a basic mechanical control, it is compatible with multiple installation locations—bathrooms, kitchens, laundry rooms—and can be wired in parallel with other controls. The device operates on 24V control circuits, where terminals commonly labeled K5 and K6 on compatible HRV/ERV control boards serve as the low‑voltage input points for the dehumidistat’s two wires. When humidity exceeds the setpoint, the MDEH1 closes the circuit between K5 and K6, signaling the ventilation unit to increase airflow or activate dehumidification mode.
Features
- 24V low‑voltage control compatible with HRV/ERV systems
- Simple 2‑wire connection (typically to K5/K6 terminals)
- Mechanical humidity sensing—no power supply required
- Rotary dial setpoint for easy user adjustment
- Normally‑open switch that closes on high humidity
- Triggers ventilation boost or dehumidification mode when humidity exceeds setpoint
- Parallel‑wiring capable with other low‑voltage controls
- Durable, passive design with long service life
- Wall‑mountable for bathrooms, laundry rooms, or general living areas
- No programming needed—set and forget operation
