Performance Analysis of Air-Tunnel Heat Exchanger Integrated into Raft Foundation
In this study, a field experiment and performance analysis of air-tunnel heat exchanger integrated with water-filled raft foundation of residential building were performed. In order to obtain better performance, conventional applications of air-tunnel inevitably have high initial cost or issues about insufficient installation space. To improve the feasibility of air tunnel heat exchanger in high-density housing, an integrated system consisting of air pipes immersed in the water-filled raft foundation was presented, taking advantage of immense amount of water and relatively stable temperature in raft foundation of building. The foundation-integrated air tunnel was applied to a residential building located in Yilan, Taiwan, and its thermal performance was measured in the field experiment. The results indicated that the cooling potential of integrated system was close to the potential of soil-based EAHE at 2 m depth or deeper. An analytical model based on thermal resistance method was validated by measurement results, and was used to carry out the dimensioning of foundation-integrated air tunnel. The discrepancies between calculated value and measured data were less than 2.7%. In addition, the return-on-investment with regard to thermal performance and economics of the application was evaluated. Because the installation for air tunnel is scheduled in the building foundation construction, the utilization of integrated system spends less construction cost compare to the conventional earth-air tunnel.
Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1127370Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 959
 J.-U. Lee, T. Kim, and S.-B. Leigh, “Applications of building-integrated coil-type ground-coupled heat exchangers—Comparison of performances of vertical and horizontal installations,” Energy and Buildings, vol. 93, pp. 99–109, 2015.
 Y. Hamada, H. Saitoh, M. Nakamura, H. Kubota, and K. Ochifuji, “Field performance of an energy pile system for space heating,” Energy and Buildings, vol. 39, no. 5, pp. 517–524, 2007.
 J. Gao, X. Zhang, J. Liu, K. S. Li, and J. Yang, “Thermal performance and ground temperature of vertical pile-foundation heat exchangers: A case study,” Applied Thermal Engineering, vol. 28, no. 17-18, pp. 2295–2304, 2008.
 D. Bozis, K. Papakostas, and N. Kyriakis, “On the evaluation of design parameters effects on the heat transfer efficiency of energy piles,” Energy and Buildings, vol. 43, no. 4, pp. 1020–1029, 2011.
 Jalaluddin, A. Miyara, K. Tsubaki, S. Inoue, and K. Yoshida, “Experimental study of several types of ground heat exchanger using a steel pile foundation,” Renewable Energy, vol. 36, no. 2, pp. 764–771, 2011.
 H. Park, S.-R. Lee, S. Yoon, and J.-C. Choi, “Evaluation of thermal response and performance of PHC energy pile: Field experiments and numerical simulation,” Applied Energy, vol. 103, pp. 12–24, 2013.
 J. Luo, H. Zhao, S. Gui, W. Xiang, J. Rohn, and P. Blum, "Thermo-economic analysis of four different types of ground heat exchangers in energy piles," Applied Thermal Engineering, vol. 108, pp. 11-19, 2016.
 K. Tsubaki and Y. Mitsutake, "Performance of ground-source heat exchangers using short residential foundation piles," Energy, vol. 14, pp. 229-236, 2016.
 C. Cheng, Y. Liu, and C. Ting, “An urban drought-prevention model using raft foundation and urban reservoir,” Building Services Engineering Research and Technology, vol. 30, no. 4, pp. 343–355, 2009.
 A.-M. Gustafsson, L. Westerlund, and G. Hellström, “CFD-modelling of natural convection in a groundwater-filled borehole heat exchanger,” Applied Thermal Engineering, vol. 30, no. 6-7, pp. 683–691, 2010.
 A.-M. Gustafsson and L. Westerlund, “Multi-injection rate thermal response test in groundwater filled borehole heat exchanger,” Renewable Energy, vol. 35, no. 5, pp. 1061–1070, 2010.
 Y. Nam and H.-B. Chae, “Numerical simulation for the optimum design of ground source heat pump system using building foundation as horizontal heat exchanger,” Energy, vol. 73, pp. 933–942, 2014.
 M. Cucumo, S. Cucumo, L. Montoro, and A. Vulcano, “A one-dimensional transient analytical model for earth-to-air heat exchangers, taking into account condensation phenomena and thermal perturbation from the upper free surface as well as around the buried pipes,” International Journal of Heat and Mass Transfer, vol. 51, no. 3-4, pp. 506–516, 2008.
 J.A. Heyns, D.G. Kröger, “Experimental investigation into the thermal-flow performance characteristics of an evaporative cooler,” Applied Thermal Engineering, vol. 30, pp. 492–498, 2010.
 P.-Y. Yu, H.-C. Hsu, Y.-C. Chang Y.-C. Chiang, C.-Y. Hsu and S.-L. Chen, “Energy-Saving Evaluation of a District Air Conditioning System Incorporated with Ground Heat Exchangers Used in an Employee's Cafeteria,” Proceedings of the 7th Asian Conference on Refrigeration and Air Conditioning, ACRA2014-319, 2014