Refrigerant Dehumidifiers

There is moisture everywhere, whether generated by the introduction of outside air, infiltration, or the process itself.  Humid air in the wrong place can impact the building function or reduce the efficiency of a production process, and dehumidification is your best means of avoiding such harmful moisture.  Cooke Industries are able to offer both refrigerant based and desiccant solutions to dehumidify the air.

Refrigerant dehumidifiers operate better in warmer humid condition applications, and are suitable for moderate dewpoints above 12°C (moisture content >8.5g/kg dry air).  They work by passing the air across a cold evaporator coil that cools it below its dew point, where the water condenses, and is then drained away.  The air may then also be reheated on a condenser, depending upon the application requirements, and cycled back into the space.

The temperature and relative humidity of the process air affect the performance of the dehumidification process.  As the dewpoint is lowered, the temperature necessary to create condensation on the cold evaporator of a refrigerant based dehumidifier also becomes lower.  If the dewpoint of the incoming air is already below 10°C, the evaporator coil temperature necessary to create condensation is likely to be sub-zero, and as airborne water vapour makes contact with the cold tube surface the condensate will begin to freeze.  Eventual ice build-up on the evaporator coil restricts heat transfer and air flow, thereby reducing the overall operating efficiency of the unit, and necessitating defrost cycles where no dehumidification occurs.

As a general guide, if the required room condition falls anywhere below the 10°C dewpoint line on a psychrometric chart, use a desiccant dehumidifier, whereas above the 12°C dewpoint line a refrigeration type dehumidifier may be more appropriate. If the required condition falls between these lines, a desiccant dehumidifier will probably be more effective, but a quality refrigeration dehumidifier may also be considered.

Contact the Cooke sales team for advice on which system works best for your particular application.


Refrigerant (condensation based) dehumidifiers for moderate dewpoints and precision control of temperature and humidity.

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