Heat recovery and desiccant wheel effect on energy saving of a solar cooling system
DOI:
https://doi.org/10.15421/cims.5.342Keywords:
ammonia-water absorption, silica gel, energy efficiency, solar energy, hot-humid climate, air conditioningAbstract
Purpose. This paper investigates the integration of a desiccant wheel into a conventional solar cooling system and the feasibility of recovering the heat rejected by the absorption chiller to regenerate the desiccant wheel, thereby improving overall system energy efficiency. Findings. The proposed system achieves solar energy savings of 18–31.5% compared to a conventional solar cooling system, depending on operating conditions. Design /Method / Approach. Mathematical models for each major component—evacuated tube solar collectors, single-stage and half-effect NH₃–H₂O absorption chillers, and a silica-gel desiccant wheel—were developed and validated against experimental data. A parametric analysis was conducted to evaluate the effects of ambient temperature, relative humidity, fresh air fraction, and regeneration temperature on system performance. Theoretical Implications. The study demonstrates that the simultaneous use of absorption and adsorption thermodynamic cycles, coupled through heat recovery, provides a theoretically grounded pathway to improving the coefficient of performance of solar-driven air conditioning systems. Practical Implications. The findings offer HVAC engineers and building designers a validated configuration for reducing solar collector area and energy consumption in solar cooling installations, particularly in hot-humid climates such as subtropical Australia. Originality / Value. Unlike previous studies that treat absorption cooling and desiccant dehumidification as independent subsystems, this work is among the first to propose recovering the absorption chiller’s rejected heat specifically for desiccant regeneration, creating a synergistic coupling that eliminates a dedicated regeneration heat source. Research Limitations / Future Research. The study is based on steady-state simulation models; experimental validation of the integrated system and transient performance analysis remain as future work. Economic and life-cycle cost analyses were not included. Article Type. Applied Research.
Downloads
References
Abdelgaied, M., Saber, M. A., Bassuoni, M. M., & Khaira, A. M. (2023). Adsorption air conditioning: a comprehensive review in desiccant materials, system progress, and recent studies on different configurations of hybrid solid desiccant air conditioning systems. Environmental Science and Pollution Research, 30(11), 28344–28372. https://doi.org/10.1007/s11356-023-25209-z
Aka, C. C., Onah, T. O., & Egwuagu, O. M. (2024). Design modification of elliptical vessel solar receiver by response surface methodology. Global Journal of Engineering and Technology Advances, 19(1), 129–142. https://doi.org/10.30574/gjeta.2024.19.1.0064
Al-Falahi, A., Alobaid, F., & Epple, B. (2020). Thermo-Economic Evaluation of Aqua-Ammonia Solar Absorption Air Conditioning System Integrated with Various Collector Types. Entropy, 22(10), 1165. https://doi.org/10.3390/e22101165
Allouhi, A., Kousksou, T., Jamil, A., Bruel, P., Mourad, Y., & Zeraouli, Y. (2015). Solar driven cooling systems: An updated review. Renewable and Sustainable Energy Reviews, 44, 159–181. https://doi.org/10.1016/j.rser.2014.12.014
Alobaid, M., Hughes, B., Calautit, J. K., O’Connor, D., & Heyes, A. (2017). A review of solar driven absorption cooling with photovoltaic thermal systems. Renewable and Sustainable Energy Reviews, 76, 728–742. https://doi.org/10.1016/j.rser.2017.03.081
Aman, J., Ting, D. S.-K., & Henshaw, P. (2014). Residential solar air conditioning: Energy and exergy analyses of an ammonia–water absorption cooling system. Applied Thermal Engineering, 62(2), 424–432. https://doi.org/10.1016/j.applthermaleng.2013.10.006
Arun, M. B., Maiya, M. P., & Murthy, S. S. (2001). Performance comparison of double-effect parallel-flow and series flow water–lithium bromide absorption systems. Applied Thermal Engineering, 21(12), 1273–1279. https://doi.org/10.1016/s1359-4311(01)00005-9
ASHRAE. (2016). 2016 ASHRAE handbook: HVAC systems and equipment (SI ed.). American Society of Heating, Refrigerating and Air-Conditioning Engineers. https://books.google.com/books?id=iwCJAQAACAAJ
Behede, B., Chakrabarti, S., & Wankhede, U. (2024). Development of rotary dehumidifier with silica-gel-based composite desiccant. Thermal Science, 28(5 Part B), 4223–4233. https://doi.org/10.2298/tsci231016174b
CEN. (2006). EN 12975-2:2006: Thermal solar systems and components—Solar collectors—Part 2: Test methods. European Committee for Standardization. https://shop.standards.ie/en-ie/standards/en-12975-2-2006-331244_saig_cen_cen_761800
Dossat, R. J., & Horan, T. J. (2002). Principles of refrigeration (5th ed.). Prentice Hall. https://books.google.com/books?id=EE62QgAACAAJ
Eicker, U., & Pietruschka, D. (2009). Design and performance of solar powered absorption cooling systems in office buildings. Energy and Buildings, 41(1), 81–91. https://doi.org/10.1016/j.enbuild.2008.07.015
Fong, K. F., Chow, T. T., Lee, C. K., Lin, Z., & Chan, L. S. (2010). Comparative study of different solar cooling systems for buildings in subtropical city. Solar Energy, 84(2), 227–244. https://doi.org/10.1016/j.solener.2009.11.002
Ge, T. S., Dai, Y. J., & Wang, R. Z. (2011). Performance study of silica gel coated fin-tube heat exchanger cooling system based on a developed mathematical model. Energy Conversion and Management, 52(6), 2329–2338. https://doi.org/10.1016/j.enconman.2010.12.047
Ge, T. S., Ziegler, F., & Wang, R. Z. (2010). A mathematical model for predicting the performance of a compound desiccant wheel (A model of compound desiccant wheel). Applied Thermal Engineering, 30(8-9), 1005–1015. https://doi.org/10.1016/j.applthermaleng.2010.01.012
González-Torres, M., Pérez-Lombard, L., Coronel, J. F., Maestre, I. R., & Yan, D. (2022). A review on buildings energy information: Trends, end-uses, fuels and drivers. Energy Reports, 8, 626–637. https://doi.org/10.1016/j.egyr.2021.11.280
Gordon, J. M., & Ng, K. C. (2000). Cool thermodynamics: The engineering and physics of predictive, diagnostic and optimization methods for cooling systems. Cambridge International Science Publishing. https://books.google.com/?id=A9yNQgAACAAJ
Herold, K. E., Radermacher, R., & Klein, S. A. (2016). Absorption chillers and heat pumps (2nd ed.). CRC press. https://doi.org/10.1201/b19625
International Energy Agency. (2023). Space cooling: Tracking report. International Energy Agency https://www.iea.org/reports/space-cooling
ISFH. (2006). Report of performance test according EN 12975-2 for a glazed solar collector (Report No. 107-06/D). Institut für Solarenergieforschung GmbH. https://www.scribd.com/document/868120592
Kodama, A., Watanabe, N., Hirose, T., Goto, M., & Okano, H. (2005). Performance of a Multipass Honeycomb Adsorber Regenerated by a Direct Hot Water Heating. Adsorption, 11(S1), 603–608. https://doi.org/10.1007/s10450-005-5992-6
Kumar, A., Said, Z., & Bellos, E. (2020). An up-to-date review on evacuated tube solar collectors. Journal of Thermal Analysis and Calorimetry, 145(6), 2873–2889. https://doi.org/10.1007/s10973-020-09953-9
Lee, S. H., & Lee, W. L. (2013). Site verification and modeling of desiccant-based system as an alternative to conventional air-conditioning systems for wet markets. Energy, 55, 1076–1083. https://doi.org/10.1016/j.energy.2013.04.029
Liu, S., Jeong, C. H., & Yeo, M. S. (2022). Development and performance analysis of a novel multi-zone hybrid desiccant cooling system. In CLIMA 2022 conference, 14th REHVA HVAC World Congress. TU Delft OPEN Publishing, Delft University of Technology. https://doi.org/10.34641/clima.2022.188
Niu, J. L., Zhang, L. Z., & Zuo, H. G. (2002). Energy savings potential of chilled-ceiling combined with desiccant cooling in hot and humid climates. Energy and Buildings, 34(5), 487–495. https://doi.org/10.1016/s0378-7788(01)00132-3
Ortiz, M., Barsun, H., He, H., Vorobieff, P., & Mammoli, A. (2010). Modeling of a solar-assisted HVAC system with thermal storage. Energy and Buildings, 42(4), 500–509. https://doi.org/10.1016/j.enbuild.2009.10.019
Pátek, J., & Klomfar, J. (1995). Simple functions for fast calculations of selected thermodynamic properties of the ammonia-water system. International Journal of Refrigeration, 18(4), 228–234. https://doi.org/10.1016/0140-7007(95)00006-w
Pesaran, A. A., & Mills, A. F. (1987). Moisture transport in silica gel packed beds—I.Theoretical study. International Journal of Heat and Mass Transfer, 30(6), 1037–1049. https://doi.org/10.1016/0017-9310(87)90034-2
Sheikhani, H., Barzegarian, R., Heydari, A., Kianifar, A., Kasaeian, A., Gróf, G., & Mahian, O. (2018). A review of solar absorption cooling systems combined with various auxiliary energy devices. Journal of Thermal Analysis and Calorimetry, 134(3), 2197–2212. https://doi.org/10.1007/s10973-018-7423-4
Solar Next AG. (2008). chillii® PSC12 – Absorption chiller. Solar Next AG. https://solarnext.de
Venegas, T., Qu, M., Wang, L., Liu, X., Gluesenkamp, K., & Gao, Z. (2023). Review of liquid desiccant air dehumidification systems coupled with heat pump: System configurations, component design, and performance. Energy and Buildings, 279, 112655. https://doi.org/10.1016/j.enbuild.2022.112655
Xu, Z. Y., & Wang, R. Z. (2014). Experimental verification of the variable effect absorption refrigeration cycle. Energy, 77, 703–709. https://doi.org/10.1016/j.energy.2014.09.044
Zambolin, E., & Del Col, D. (2010). Experimental analysis of thermal performance of flat plate and evacuated tube solar collectors in stationary standard and daily conditions. Solar Energy, 84(8), 1382–1396. https://doi.org/10.1016/j.solener.2010.04.020
Zhang, L. Z., & Niu, J. L. (2002). Performance comparisons of desiccant wheels for air dehumidification and enthalpy recovery. Applied Thermal Engineering, 22(12), 1347–1367. https://doi.org/10.1016/s1359-4311(02)00050-9
Zhang, X. J., Dai, Y. J., & Wang, R. Z. (2003). A simulation study of heat and mass transfer in a honeycombed rotary desiccant dehumidifier. Applied Thermal Engineering, 23(8), 989–1003. https://doi.org/10.1016/s1359-4311(03)00047-4
Downloads
Published
Issue
Section
Categories
License
Copyright (c) 2026 Christian Chikezie Aka, Thomas Okechukwu Onah, Barnabas Uchenna Ugwuanyi (Author)
This work is licensed under a Creative Commons Attribution 4.0 International License.
All articles published in the journal Challenges and Issues of Modern Science are licensed under the Creative Commons Attribution 4.0 International (CC BY) license. This means that you are free to:
- Share, copy, and redistribute the article in any medium or format
- Adapt, remix, transform, and build upon the article
as long as you provide appropriate credit to the original work, include the authors' names, article title, journal name, and indicate that the work is licensed under CC BY. Any use of the material should not imply endorsement by the authors or the journal.
