ADI/ADO 1500-4500 −30°C / −18°C Freezer Room Dehumidifier

Adsorption Technology for Freezer Rooms

The ADI/ADO series are silica gel rotor adsorption dehumidifiers developed specifically for freezer rooms operating between −30°C and −18°C. Process air is drawn from the freezer room and passed through the silica gel rotor, which adsorbs the moisture and dries the air. Regeneration air is drawn from an adjacent room or outside, heated by electric heaters, and passes through the rotor to restore its adsorption capacity. This continuously controls humidity inside the freezer room, preventing ice and frost formation.

Humid air drawn from the freezer room (down to −30°C) passes through a G4 filter and is directed to the silica gel rotor.

The silica gel rotor adsorbs moisture from process air across the −30°C to −18°C range; the dried airstream is returned to the freezer room.

Air drawn from an adjacent room is heated by electric heaters to strip moisture from the rotor; moisture-laden air is discharged outside.

Continuous humidity control prevents ice and frost formation on freezer room surfaces across the −30°C / −18°C range, improving evaporator efficiency and reducing energy costs.

Engineered to operate at full capacity across the −30°C to −18°C freezer room temperature range. Freezer-room-rated galvanised steel and AISI 304 stainless steel sandwich panel housing with insulation against condensation and ice build-up.

Honeycomb silica gel rotor optimised for high adsorption efficiency across the −30°C to −18°C range. Not damaged by fan failure, non-combustible and non-flammable.

Belt drive system designed for reliable operation in cold environments. Outer-edge rotor drive with special tension maintenance device. Ball bearings and steel rotor shaft.

Electric steel-element star-connected heating coil with 90°C temperature rise, enabling effective rotor regeneration from cold ambient conditions. Single-step control standard; optional PWM proportional control for energy savings.

Process and regeneration fans directly coupled to IP55 / ISO F Class B three-phase motors, selected for cold environment operation. Accessible for maintenance by removing the inspection panel.

Separate G4 filters on process and regeneration air inlets; optional F5/F7/F9. On the ADI version, filters can be changed from outside the freezer room via remote access.

PLC control with LED terminal; regeneration temperature regulation, thermal protection, post-cooling timer, alarm management, humidity and damper control. Step control from external humidistat and analogue input. RS485 MODBUS for integration with cold store BMS/SCADA systems.

ADI (internal): mounted inside the freezer room close to a wall — minimal ducting, minimal heat loss. ADO (external): mounted outside the freezer room — easy maintenance access, no heat load to the freezer room. Both versions use standard spiral duct connections.