Review of Liquid Desiccant Technology for HVAC Applications

A thermally driven air conditioner that uses liquid desiccants as the working fluid may be an attractive alternative to the compressor-based technology that is now used in most HVAC applications. The operation of a liquid-desiccant air conditioner is first explained and several basic concepts are reviewed. This review focuses on the development of liquid-desiccant conditioners and regenerators that are better suited to comfort conditioning (as opposed to industrial dehumidification). This includes work on conditioners and regenerators that use low flow rates of desiccants and have internal heat exchange. These conditioners and regenerators will have lower pump and fan power than packed-bed units, and will be much less likely to introduce desiccant droplets into the process air. Work to identify and develop regenerators that have COPs over 1.0 and research on alternative liquid desiccants is also reviewed.