International Journal of Environment (ISSN: 2186-0009)  

Utilization of Desiccant Air-Conditioning System for Improvement in Greenhouse Productivity: A Neglected Area of Research in Pakistan
Muhammad Sultan, Takahiko Miyazaki, Shigeru Koyama, and Bidyut Baran Saha
Farmers in Pakistan are used to grow the off-seasonal vegetables and fruits in greenhouses/tunnels but facing severe problems of humidity and temperature. This results in diseases, pests and fungus attack and finally farmers have to bear a big yield loss. In this study, the air conditioning system demands are determined by keen research on greenhouse requirements and ambient conditions through psychometric analysis based on vapor pressure deficit (VPD). Certainly the desiccant air conditioning (DAC) system has a potential to deal with such kind of situations and the heat of adsorption can be used efficiently. Solid DAC system has not only shown the promising results to control humidity but also shown the potential to deal temperature stresses by addition of low cost temperature controlling devices. As it can deal the humidity and temperature distinctly so it can be operated in more flexible way as compared to vapor compression air conditioning system. This is a novel research in this territory and promising vigorous outcomes. In present work it is projected that the regeneration of desiccant can be done by harnessing the solar thermal energy. The paper demonstrates that desiccant system is a feasible solution for cooling/heating and dehumidification of greenhouse environment and highly substantial for Pakistan's conditions.
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