INTRODUCTION
The APSOL DECKER low dew point desiccant dehumidifier is specifically engineered for applications requiring ultra-low dew points from -20°C to -80°C, while achieving up to 35% energy savings.
DECKER engineers collaborate with clients to provide turnkey solutions for low dew point rooms, either based on standard equipment or customized to meet specific requirements. We support contractors and owners throughout the entire process—from concept development, design, and equipment manufacturing, to installation assistance, commissioning, and lifecycle maintenance.
LOW DEW POINT DESICCANT DEHUMIDIFIER CONSTRUCTION
Desiccant Rotor: NICHIAS (Japan) rotor using silica gel / hydrophilic zeolite / combination of silica gel and hydrophilic zeolite.
Frame: Thermally broken extruded aluminum frame, rigid structure to prevent air leakage.
Cabinet Panels: 50–100 mm thick insulated panels with PIR insulation to prevent condensation, reduce heat transfer, and provide sound attenuation.
Internal Mechanical Components: Made of stainless steel SUS-304.
Rotor Reactivation Heat Source: Supports multiple decarbonized heat sources, enabling clean and green energy operation.
Direct-Drive Fans (KRUGER): Backward-curved blades for overload protection, simple construction for high durability, airflow and pressure controlled via VSD.
Air Filtration: G4 + F8 + HEPA (configurable according to cleanroom requirements).
Control System: PLC with touch-screen HMI, integrated monitoring of temperature, humidity, and dew point.
BASIC CONFIGURATION
Configuration: Single desiccant rotor.
The single-rotor low dew point dehumidifier configuration is suitable for applications requiring a dew point around -40°Cdp, using a controlled amount of fresh air for rotor regeneration.
Low Dew Point Dehumidification System Diagram – Single Desiccant Rotor
Operating Principle:
● Process Air Stream: Return air from the controlled room maintained at -40°Cdp is mixed with a portion of fresh air for desiccant rotor regeneration. This mixed air is typically precooled by the first cooling coil to enhance the moisture removal efficiency of the desiccant rotor. The dry air exiting the rotor is then further cooled by a second cooling coil before being supplied to the room.
● Regeneration Air Stream: Air exiting the primary cooling coil passes through a rotor cooling section, absorbing heat from the rotor to save energy on cooling the process air and reduce heating energy for regeneration. This air is then reheated to regenerate the rotor, ensuring it is fully dried and ready for the next moisture removal cycle.
Configuration: Dual desiccant rotors.
The dual-rotor low dew point dehumidifier configuration is suitable for applications requiring dew points down to –80°C DP and for handling large volumes of fresh air to remove odors and solvents.
Low Dew Point Dehumidification System Diagram – Dual Desiccant Rotors
Operating Principle:
● Process air stream: Large volumes of fresh air are first pre-cooled in the primary cooling coil for initial moisture removal, then further dehumidified in the first desiccant rotor. The air leaving rotor 1, now at higher temperature and low humidity, is mixed with return air at –80 °C DP. This mixed air is then cooled in the secondary cooling coil to enhance the dehumidification efficiency of rotor 2. The dry air leaving rotor 2, with a dew point between –85 °C DP and –95 °C DP, is supplied to the controlled space.
● Reactivation air stream: Air leaving the secondary cooling coil, at low temperature and dew point, passes through the cooling chamber of rotor 2 to recover heat from the rotor, saving energy for both the process air cooling and the reactivation heating. The air then continues to be heated to fully reactivate the rotor, preparing it for the next dehumidification cycle.
APPLICATIONS
Lithium battery production / dry rooms (cell assembly, electrolyte filling): Prevent moisture during electrode mixing, coating/drying, and contact with lithium/electrolyte; reduce defects and risk of moisture-induced reactions. Dew point range: −40 °C DP to −75 °C DP.
Semiconductors / wafer fab & advanced packaging: Lithography, plasma processes, and thin-film steps sensitive to moisture; ultra-low PDP required for clean compressed air and controlled environment. Dew point range: −50 °C DP to ≤−70 °C DP for clean air (CDA) and critical processing steps.
Pharmaceuticals — lyophilization (freeze-drying) and ultra-sensitive processing: Ensure effective drying, prevent condensation during rotor reactivation, and maintain drug quality. Dew point range: −40 °C DP to −70 °C DP depending on the process; frost-point/dew-point control is critical.
Specialty & ultra-pure industrial gases (semiconductor gas, specialty gases, instrument air): Prevent hydrate formation and condensation in piping/valves, protect measuring instruments/analyzers, and safeguard chemical processes. Dew point range: −40 °C DP to ≤−70 °C DP.
Testing / storage of hygroscopic materials (specialty inks, silicates, certain polymers, optical materials): Prevent moisture absorption that can alter product properties, shelf life, and measurement accuracy. Dew point range: −40 °C DP to −60 °C DP.
