Dehumidification by alternative cooling systems - sorption-supported dehumidification with different liquid salt solutions.

The traditional way to dehumidify the outdoor air in a heating, ventilating and airconditioning (ENAC) system is by cooling the air temperature down below the dew point.For this process a refrigeration system is necessary to realise these low temperatures.Nowadays the disadvantages of refrigeration systems are widely known. An alternativemethod to dehumidify the air is by separating the process of dehumidification and cooling.There are different ways to get low supply air temperatures for cooling the indoor spaces. It ispossible for example to use well water, an evaporative cooling system or, of course, arefrigeration system with relatively high evaporation temperature. This cooling componentsare well known and already in practice so that this paper focuses on the dehumidificationprocess.The paper gives a general view of the adsorptive and absorptive dehumidificationcomponents. Then a new dehumidifier which uses a liquid desiccant will be described. Asmall prototype was tested in an experimental plant in the laboratory of the Institute ofApplied Thermodynamics and Air Conditioning in Essen. The design of the dehumidifier andthe first results of the measurements will be presented.