Liquid desiccant materials and dehumidifiers – A review M. Mujahid Rafique, P. Gandhidasan n , Haitham M.S. Bahaidarah Department of Mechanical Engineering, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia article info Article history: Received 5 November 2014 Received in revised form 19 August 2015 Accepted 21 November 2015 Keywords: Liquid desiccant Composite desiccant materials Adiabatic dehumidifier Inner cooling abstract It is important to decrease the energy cost of heating, ventilating and air conditioning (HVAC) systems without compromising indoor air quality and comfort conditions due to the rising cost of fossil fuels and other environmental concerns. Liquid desiccant cooling systems are one of the alternatives in this regard which is not only environmental friendly (no use of any refrigerant which deplete ozone layer) but at the same time make a good use of alternative sources of energy like, solar, biomass etc. This paper presents different commercially available liquid desiccants and their composites which combines the properties of two or more desiccant materials for better performance. A good desiccant should have better moisture absorption capability and lower temperature of regeneration. This paper also includes the different configurations of liquid desiccant dehumidifiers and their advantages as well as drawbacks. Some new configurations of liquid desiccant dehumidifiers have been introduced which greatly improves the sys- tem overall performance. Moreover, a summary of the performance parameters has been made to analyze the system performance. This review is meaningful for the research and technical development process of liquid desiccant technology. & 2015 Elsevier Ltd. All rights reserved. Contents 1. Introduction ........................................................................................................ 179 1.1. Energy and environmental issues ................................................................................. 180 1.2. Human comfort and building indoor air quality ..................................................................... 180 2. Alternative cooling systems and dehumidification ......................................................................... 180 3. Liquid desiccant cooling .............................................................................................. 180 3.1. Performance parameters ........................................................................................ 181 3.2. Comparison of desiccant cooling to conventional cooling .............................................................. 181 3.3. Advantages of using liquid desiccants ............................................................................. 182 4. Liquid desiccant materials ............................................................................................. 183 4.1. Composite desiccant materials ................................................................................... 184 5. Liquid desiccant dehumidifiers ......................................................................................... 184 5.1. Adiabatic dehumidifiers ........................................................................................ 185 5.2. Dehumidifier with inner cooling.................................................................................. 186 6. Developments of liquid desiccant dehumidifier ............................................................................ 189 7. Dehumidifier packing material selection ................................................................................. 190 8. Flow pattern inside the dehumidifier .................................................................................... 191 9. Future view of research on the field of desiccant cooling technology .......................................................... 192 9.1. Making the best use of technology................................................................................ 192 10. Conclusions ........................................................................................................ 193 Acknowledgments ....................................................................................................... 193 References ............................................................................................................. 193 Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/rser Renewable and Sustainable Energy Reviews http://dx.doi.org/10.1016/j.rser.2015.11.061 1364-0321/& 2015 Elsevier Ltd. All rights reserved. n Corresponding author. Tel.: þ966 13 860 2950. E-mail address: pgandhi@kfupm.edu.sa (P. Gandhidasan). Renewable and Sustainable Energy Reviews 56 (2016) 179–195