Desiccant dehumidification is widely used in cold room applications but one concern of cold store operators is that, with traditional desiccant dehumidifiers, the returning air is at a higher temperature than the air in the cold store.
To address this, John Barker, director of Humidity Solutions, explains that the DFRIGO series “offers the option of heat recovery, where the dried air passes through a recovery plate heat exchanger and gives up the sensible heat gained in the desiccant rotor before passing back to the cold room.
“The result of this heat recovery process,” he says, “is that there is no change in enthalpy and, therefore, no net transfer of heat to or from the surroundings. As a result, the dried process air returns to the cold room at the same temperature as it left.
“Desiccant dehumidification without heat recovery will still deliver significant improvements in energy efficiency simply by preventing icing of the coils. When specifying these systems, therefore, it is important to strike the right balance between the additional efficiency delivered by heat recovery and the extra investment this entails.
“Ultimately, it is a matter of understanding the requirements of each individual application and then choosing the solution that provides best value.”