[01] Jani Dilip Batukray, Department of Mechanical Engineering, GEC-Dahod, Gujarat Technological University (GTU), Ahmedabad, India.

High humidity level of the indoor moist air has adverse effect on human health as it perceived indoor air quality (IOQ). Its major threat is observed as sensory irritation in eyes and respiratory systems due to drastic reduction in humidity sometimes due to overcooling. This overview has reviewed many literatures containing desiccant based alternative cooling as option to vapor compression based traditional cooling in maintaining efficient control over indoor humidity the effects of extended exposure to humidity on perceived IAQ over human health, sensory irritation symptoms in eyes and airways, work performance, sleep quality, virus survival, and voice disruption. As efficient control humidity may positively impact perceived IAQ, eye symptomatology, and possibly human health issues in the hospital mild environment. Amelioration in indoor air humidity level appears to reduce nasal symptoms in patients suffering from obstructive apnea syndrome, while no clear improvement on voice production has been identified, except for those with vocal fatigue. Both either low or high moisture content and perhaps even better relative humidity in range 50-60% prevents the transmission and survival of influenza virus and other bacterial growth in many studies. Maintenance of indoor humidity in above range as one of the IAQ parameter appears to reflect different perceptions among other odour, dustiness and possibly exacerbated by desiccation effect of low air humidity.

Desiccant Cooling, Desiccant Dehumidification, Human Health, Humidity Control

[01] ASHRAE. (2007). Ventilation for Acceptable Indoor Air Quality, Atlanta GA, American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE Standard 62.1-2007). [02] Backman, H, Haghighat, F. (1999). Indoor-air quality and ocular discomfort. J. Am. Optom. Assoc., Vol. 70, pp. 309-316. [03] Andersen, I. B., Lundqvist, G. R., Jensen, P. L., Proctor, D. F.(1974). Human response to 78 hour exposure to dry air. Arch. Environ. HealthVol. 29, pp. 319-324. [04] Jani DB, Mishra M, Sahoo PK. Performance analysis of hybrid solid desiccant–vapor compression air conditioning system in hot and humid weather of India. Building Services Engineering Research and Technology 2016; 37: 523-538. [05] Bhabhor, K., Jani, D. B. Progressive development in solid desiccant cooling: A review. International Journal of Ambient Energy 2019; DOI: 10.1080/01430750.2019.1681293. [06] Jani, D. B., et al. (2019) A review on use of TRNSYS as simulation tool in performance prediction of desiccant cooling cycle. Journal of Thermal Analysis and Calorimetry DOI: 10.1007/s10973-019-08968-1. [07] Zhou, X., Goldsworthy, M., Sproul, A., Performance investigation of an internally cooled desiccant wheel. Applied Energy 2018: 224: 382-397. [08] Jani, D. B., M. Mishra, and P. K. Sahoo. 2015. Performance studies of hybrid solid desiccant - vapor compression air-conditioning system for hot and humid climates. Energy and Buildings 102: 284-292. [09] Jani, D. B., M. Mishra, and P. K. Sahoo. 2016. Performance prediction of rotary solid desiccant dehumidifier in hybrid air-conditioning system using artificial neural network. Applied Thermal Engineering 98: 1091–1103. [10] Wang N, Zhang J, Xia X. Desiccant wheel thermal performance modeling for indoor humidity optimal control. Applied Energy 2013; 112: 999–1005. [11] Jani, D. B., M. Mishra, and P. K. Sahoo. 2016. Performance prediction of solid desiccant - vapor compression hybrid air-conditioning system using artificial neural network. Energy 103: 618-629. [12] Jani, D. B., M. Mishra, and P. K. Sahoo. 2016. Experimental investigation on solid desiccant – vapor compression hybrid air- conditioning system in hot and humid weather. Applied Thermal Engineering 104: 556–564. [13] Jani, D. B., M. Mishra, and P. K. Sahoo. 2017. Application of artificial neural network for predicting performance of solid desiccant cooling systems- A review. Renewable and Sustainable Energy Reviews 80: 352-366. [14] Factor, H. M, and Grossman, G. (1980). Packed bed dehumidifier/regenerator for solar air conditioning with liquid desiccants. Solar Energy Vol. 24 (6), pp. 541–50. [15] Buckland, E E., Tyrrell, D. A. J. (1962). Loss of infectivity on dryingvarious viruses. NatureVol. 195, pp. 1063-1064. [16] Cole, P. (1953). Further observations on the conditioning of respiratory air, J. Laryngol. Vol. 67, pp. 669-681. [17] Sato, M., Fukayo, S., Yano, E. (2003). Adverse environmental health effects of ultra-lowrelative humidity indoor air. J. Occup. HealthVol. 45, pp. 133-136. [18] Sundell, J., Lindvall, T. (1993). Indoor air humidity and sensation of dryness as riskindicators of SBS. Indoor AirVol. 3, pp. 382-390. [19] Grossman, G., Johannsen, A,, and Solar, A. (1981). Cooling and air conditioning. Progress in Energy and CombustionScience Vol. 7, pp. 185–228. [20] Elsayed, M. M, Gari, H. N, and Radhwan, A. M (1993). Effectiveness of heat and mass transfer in packed beds of liquid desiccant system. Renewable Energy Vol. 3: 661–8. [21] Henning, H. M. (2001). The potential of solar energy use in desiccant cooling cycles. International Journal of Refrigeration Vol. 24 (3), pp. 220–229. [22] Li, Z., Kobayashi, N., Watanabe, F., and Hasatani, M. (2002). Sorption drying of soybean seeds with silica gel. Drying Technology Vol. 20 (1), pp. 223–233. [23] Cui, Q., Chen, H., Tao, G., and Yao, H.(2005). Performance study of new adsorbent for solid desiccant cooling. Energy Vol. 30 (2), pp. 273-9. [24] Hamed, A., and Ahmed, M. (2005). Experimental investigation on the adsorption/desorption processes using solid desiccant in an inclined-fluidized bed. Renewable Energy Vol. 30, pp. 1913–21. [25] Li, X. W., Zhang, X. S., and Quan, S. (2011). Single-stage and double-stage photovoltaic driven regeneration for liquid desiccant cooling system. Applied Energy Vol. 88 (12), pp. 4908–4917. [26] Crofoot, L., and Harrison, S. (2012). Performance evaluation of a liquid desiccant solar air conditioning system. Energy Procedia Vol. 30, pp. 542–550. [27] Al-Abidi, A. A., Mat, S., Sopian, K., Sulaiman, M. Y., and Mohammad, A. Th. (2013). Experimental study of PCM melting in triplex tube thermal energy storage for liquid desiccant air conditioning system. Energy and Buildings Vol. 60, pp. 270–279. [28] Chen, Y., Yin, Y., and Zhang, X. (2014). Performance analysis of a hybrid air-conditioning system dehumidified by liquid desiccant with low temperature and low concentration. Energy and Buildings Vol. 77, pp. 91–102. [29] Buker, M. S., and Riffat, S. B. (2015). Recent developments in solar assisted liquid desiccant evaporative cooling technology review. Energy and Buildings Vol. 96, pp. 95–108. [30] Zheng, X., Ge, T. S., Jiang, Y. and Wang, R. Z. (2015). Experimental study on silica gel-LiCl composite desiccants for desiccant coated heat exchanger. International Journal of RefrigerationVol. 51, pp. 24–32. [31] Kim, M., Yoon, D., Kim, H., and Jeong, J. (2016). Retrofit of a liquid desiccant and evaporative cooling-assisted 100% outdoor air system for enhancing energy saving potential. Applied Thermal Engineering Vol. 96, pp. 441–453. [32] Rafique, M. M., Gandhidasan, P., and Bahaidarah, M. S. (2016a). Liquid desiccant materials and dehumidifiers – a review. Renewable and Sustainable Energy Reviews Vol. 56, pp. 179–195. [33] Rafique, M. M., Gandhidasan, P., Rehman, S., and Al-Hadhrami, L. M. (2016b). Performance analysis of a desiccant evaporative cooling system under hot and humid conditions Environmental Progress & Sustainable Energy Vol. 35 (5), pp. 1476–1484. [34] Jani, D. B., Mishra, M., and Sahoo, P. K. (2016). Solid desiccant air conditioning – A state of the art review. Renewable and Sustainable Energy Reviews Vol. 60, pp. 1451–1469. [35] Federico, B., and Furbo, S. (2017). Development and validation of a detailed TRNSYS Matlab model for large solar collector fields for district heating applications. Energy DOI: 10.1016/j.energy.2017.06.146. [36] Jani, D. B., Mishra, M., and Sahoo, P. K. (2017). A critical review on solid desiccant based hybrid cooling systems. International Journal of Air-conditioning and Refrigeration Vol. 25, pp. 1-10. [37] Jani, D. B., Mishra, M., and Sahoo, P. K. (2018). A critical review on application of solar energy as renewable regeneration heat source in solid desiccant – vapor compression hybrid cooling system. Journal of Building Engineering Vol. 18, pp. 107-124. [38] Jani, D. B., Mishra, M., and Sahoo, P. K. (2018). Performance analysis of a solid desiccant assisted hybrid space cooling system using TRNSYS. Journal of Building Engineering Vol. 19, pp. 26-35. [39] Jani, D. B., Mishra, M., and Sahoo, P. K. (2018). Investigations on effect of operational conditions on performance of solid desiccant based hybrid cooling system in hot and humid climate. Thermal Science and Engineering Progress Vol. 7, pp. 76-86. [40] Jani, D. B., Lalkiya, D., and S. Patel. (2018). A critical review on evaporative desiccant cooling. International Journal of Innovative and Emerging Research in Engineering Vol. 5 (1), pp. 24-29. [41] Jani, D. B., Mishra, M., and Sahoo, P. K. (2018). Applications of solar energy. Springer, Singapore, ISBN 978-981-10-7205-5. [42] Dadi, M. J., Jani, D. B. (2019) Solar Energy as a Regeneration Heat Source in Hybrid Solid Desiccant – Vapor Compression Cooling System – A Review. Journal of Emerging Technologies and Innovative Research Vol. 6 (5), pp. 421-425. [43] Toftum, H., Jorgensen, AS, Fanger, PO.(1998). Upper limits of air humidity forpreventing warm respiratory discomfort. Energy and Buildings Vol. 28, pp. 15-23. [44] Wyon, DP.(1992). Sick buildings and the experimental approach. Environmental TechnologyVol. 13 (4), pp. 313-322. [45] Schnieders, J. (2009). Passive Houses in South West Europe, A quantitative investigation ofsome passive and active space conditioning techniques for highly energy efficient dwellingsin the South West European region. dissertation, PHI. [46] Reinikainen, LM, Aunela-Tapola, L., Jaakkola, JJK. (1997). Humidification and perceivedindoor air quality in the office environment. Occup. Environm. Med. Vol. 54, pp. 322-327. [47] Liviana JE, Rohles, FH and Bullock, OD.(1988). Humidity, comfort and contact lenses, ASHRAE Transactions Vol. 94 (1), pp. 3-11. [48] Egawa, M., Oguri, M, Kuwahara, T. and Takahashi, M. (2002). Effect of exposure of human skin to a dry environment. Skin Research and TechnologyVol. 8, pp. 212-218.