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Thermal comfort enhancement in Oum El Bouaghi (Algeria) using PCM-enhanced walls and natural ventilation: a comparative CFD study
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  • Published: 25 March 2026

Thermal comfort enhancement in Oum El Bouaghi (Algeria) using PCM-enhanced walls and natural ventilation: a comparative CFD study

  • Moussa Aidi1,2,
  • Yamina Harnane1,2,
  • Müslüm Arıcı3,
  • Lyes Bordja1,2 &
  • …
  • Tibor Poós4 

Scientific Reports , Article number:  (2026) Cite this article

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We are providing an unedited version of this manuscript to give early access to its findings. Before final publication, the manuscript will undergo further editing. Please note there may be errors present which affect the content, and all legal disclaimers apply.

Subjects

  • Energy science and technology
  • Engineering

Abstract

This study presents a comparative parametric investigation of the combined effect of phase change materials (PCMs) integrated into brick walls and natural ventilation strategies on indoor thermal comfort under the arid summer climate of Oum El Bouaghi, Algeria. A CFD analysis using ANSYS Fluent evaluated four PCMs (hexahydrate, n-hexadecane, n-eicosane, and n-octadecane) and three ventilation configurations with different inlet–outlet arrangements. The PCM performance was analyzed over seven consecutive July days using measured outdoor temperatures as boundary conditions, while ventilation scenarios were assessed during representative hot days to reduce computational cost. Thermal performance was assessed through indoor air temperature, wall heat flux, effective draft temperature (EDT), and the field synergy angle between velocity and temperature-gradient vectors. Although n-hexadecane exhibited the highest instantaneous heat absorption and the lowest internal surface temperatures during peak periods, its early phase transition limited sustained thermal regulation. In contrast, n-octadecane, with a melting range of 301–302 K, provided more stable and prolonged temperature control, making it the most suitable PCM among the investigated candidates when considering both thermal stability and indicative material cost. A parametric thickness analysis showed that increasing PCM thickness up to 10–15 cm led to diminishing thermal returns, achieving up to 52% reduction in daily integrated heat flux compared to the brick-only reference wall under July conditions. However, this range represents an upper-bound performance scenario; from an engineering feasibility perspective, thinner PCM layers (e.g., 5–10 cm) may provide a more practical balance between constructability and thermal benefit. The ventilation configuration with a bottom inlet and top outlet on opposite walls yielded the most stable indoor conditions due to improved air circulation. The study also introduces EDT and a synergy parameter to quantify the interaction between heat transfer and ventilation. Overall, combining PCM-enhanced walls with climate-adaptive ventilation demonstrates significant potential for reducing cooling demand and improving sustainable building performance in hot climates.

Data availability

The datasets used and/or analysed during the current study available from the corresponding author on reasonable request.

Abbreviations

cp :

Specific heat capacity (kJ \({kg}^{- 1}\) \({K }^{- 1}\))

g:

Gravitational acceleration (m \({s}^{- 2}\))

h:

Transfer coefficient (W \({m}^{-2}{K }^{- 1}\))

\({\text{h}}_{0} {\text{h}}_{\text{out}}\) :

Border conditions transfer coefficient (W \({m}^{-2}{K }^{- 1}\))

H:

Specific enthalpy (\(Jk{g}^{-1}\))

\({H}_{\text{sens}}\) :

Sensible enthalpy (\(Jk{g}^{-1}\))

\({H}_{\text{lat}}\) :

Latent enthalpy (\(Jk{g}^{-1}\))

k:

Turbulent kinetic energy \({(m}^{2}\)/\({s}^{2}\))

P:

Pressure (N \({\text{m}}^{- 2}\))

Pr:

Prandtl number (1)

T:

Temperature (K)

t:

Time (s) (s)

u:

Velocity (m \({s}^{- 1}\))

\({\text{u}}_{\text{i}}\) \({\text{u}}_{\text{j}}\) :

The velocity components in the direction of each spatial coordinate in a Cartesian coordinate system (m \({s}^{- 1}\))

U:

Velocity (m \({s}^{- 1}\))

v:

Velocity vector (m \({s}^{- 1}\))

w:

Wind speed (m \({s}^{- 1}\))

X:

Spatial direction

Y:

Spatial direction

\({\text{x}}_{\text{i}}\) \({\text{x}}_{J}\) :

Spatial coordinates in cartesian coordinate system

β:

Thermal expansion coefficient (\({\text{K}}^{- 1}\))

\(\uplambda\) :

Thermal conductivity (W \({\text{m}}^{- 1}{\text{K}}^{- 1}\))

ρ:

Density (kg \({m}^{-3}\))

\(\upxi ,\upeta\) :

Phase field parameters used in PCM phase-change modeling

\({\text{e}}_{\text{i}}\) :

Unit vector in the i-direction

θ:

Synergy angle, representing the angle between velocity and temperature gradient vectors°

\(\mu\) :

Molecular (dynamic) viscosity of the fluid Pa s

\({\mu }_{t}\) :

Turbulent viscosity (Pa s)

lat:

latent

ref:

reference

PCM:

phase change material

sens:

sensible

EDT:

Effective draft temperature

References

  1. Cziszter, K. et al. Comparative studies and research on energy optimization of non-residential buildings. J. Appl. Eng. Sci. 12(1), 27–32 (2022).

    Google Scholar 

  2. Ismail, K. et al. Contribution of advanced windows and façades to buildings decarbonization: A comprehensive review. Eur. J. Sustain. Dev. Res. https://doi.org/10.29333/ejosdr/14580 (2024).

    Google Scholar 

  3. Huang, J. et al. Advances and applications of phase change materials (PCMs) and PCMs-based technologies. ES Mater. Manuf. 13, 23–39 (2021).

    Google Scholar 

  4. Yang, Z. L. et al. Advances in phase change materials, heat transfer enhancement techniques, and their applications in thermal energy storage: A comprehensive review. J. Energy Storag. 87, 111329 (2024).

    Google Scholar 

  5. Ma, K. et al. Application and research progress of phase change materials in biomedical field. Biomater. Sci. 9(17), 5762–5780 (2021).

    Google Scholar 

  6. Zhang, H. et al. Super-elastic smart phase change material (SPCM) for thermal energy storage. Chem. Eng. J. 411, 128482 (2021).

    Google Scholar 

  7. Shengxin, E. et al. Effects of the different phase change materials on heat dissipation performances of the ternary polymer Li-ion battery pack in hot climate. Energy 282, 128805 (2023).

    Google Scholar 

  8. Shengxin, E. et al. Effects of composite cooling strategy including phase change material and cooling air on the heat dissipation performance improvement of lithium ion power batteries pack in hot climate and its catastrophe evaluation. Energy 283, 129074 (2023).

    Google Scholar 

  9. Jiaqiang, E. et al. Effects of heating film and phase change material on preheating performance of the lithium-ion battery pack with large capacity under low temperature environment. Energy 284, 129280 (2023).

    Google Scholar 

  10. Ma, Y. et al. Three-dimensional EG@ MOF matrix composite phase change materials for high efficiency battery cooling. Energy 278, 127798 (2023).

    Google Scholar 

  11. Ma, Y. et al. EG@ Bi-MOF derived porous carbon/lauric acid composite phase change materials for thermal management of batteries. Energy 272, 127180 (2023).

    Google Scholar 

  12. Ma, Y. et al. Development of hierarchical MOF-based composite phase change materials with enhanced latent heat storage for low-temperature battery thermal optimization. Energy 283, 129001 (2023).

    Google Scholar 

  13. Ma, Y. et al. N-doped EG@ MOFs derived porous carbon composite phase change materials for thermal optimization of Li-ion batteries at low temperature. Energy 286, 129637 (2024).

    Google Scholar 

  14. Yi, F. et al. Effects analysis on heat dissipation characteristics of lithium-ion battery thermal management system under the synergism of phase change material and liquid cooling method. Renew. Energy 181, 472–489 (2022).

    Google Scholar 

  15. Alam, M. et al. A comparative study on the effectiveness of passive and free cooling application methods of phase change materials for energy efficient retrofitting in residential buildings. Procedia Eng. 180, 993–1002 (2017).

    Google Scholar 

  16. Koley, S. Electrochemistry of phase-change materials in thermal energy storage systems: A critical review of green transitions in built environments. Trend. Sci. 21(10), 8538–8538 (2024).

    Google Scholar 

  17. Barbhuiya, S., Das, B. & Adak, D. Phase change materials in buildings: Fundamentals, applications, and future perspectives. In Innovations in Energy Efficient Construction Through Sustainable Materials 207–262 (IGI Global, 2025).

    Google Scholar 

  18. Wu, W. et al. Advanced thermal energy storage made of a ternary CPCM with two phase change temperatures in building walls. Energy Build. https://doi.org/10.1016/j.enbuild.2024.114445 (2024).

    Google Scholar 

  19. Geetha, N. & Velraj, R. Passive cooling methods for energy efficient buildings with and without thermal energy storage–A review. Energy Educ. Sci. Technol. A Energy Sci. Res. 29(2), 913–946 (2012).

    Google Scholar 

  20. Osterman, E., Butala, V. & Stritih, U. PCM thermal storage system for ‘free’heating and cooling of buildings. Energy Build. 106, 125–133 (2015).

    Google Scholar 

  21. Alavi, S. M. R. et al. Multi-objective optimization of free cooling potential through PCM based storage system. J. Build. Eng. 86, 108678 (2024).

    Google Scholar 

  22. Kurdi, A. et al. Potential phase change materials in building wall construction—a review. Material. 14(18), 5328 (2021).

    Google Scholar 

  23. Inard, C., Pfafferott, J. & Ghiaus, C. Free-running temperature and potential for free cooling by ventilation: A case study. Energy Build. 43(10), 2705–2711 (2011).

    Google Scholar 

  24. Waqas, A., Ali, M. & Ud Din, Z. Performance analysis of phase-change material storage unit for both heating and cooling of buildings. Int. J. Sustain. Energy 36(4), 379–397 (2017).

    Google Scholar 

  25. Waqas, A. & Kumar, S. Thermal performance of latent heat storage for free cooling of buildings in a dry and hot climate: An experimental study. Energy Build. 43(10), 2621–2630 (2011).

    Google Scholar 

  26. Waqas, A. & Kumar, S. Utilization of latent heat storage unit for comfort ventilation of buildings in hot and dry climates. Int. J. Green Energy 8(1), 1–24 (2011).

    Google Scholar 

  27. Darzi, A. R. et al. Numerical investigation of free-cooling system using plate type PCM storage. Int. Commun. Heat Mass Transf. 48, 155–163 (2013).

    Google Scholar 

  28. Muthuvelan, T. et al. Experimental investigation of free cooling using phase change material-filled air heat exchanger for energy efficiency in buildings. Adv. Build. Energy Res. 12(2), 139–149 (2018).

    Google Scholar 

  29. Kukadia, V., Work Package 2: Performance of naturally ventilated buildings–final monitoring report. In Pan-European Project Encouraging the Use of Natural Ventilation in Office-type Buildings (1998).

  30. Suparna, S., Jagbir, S. & Bharat Raj, S. Wind-driven natural ventilation – The wind tower as a strategy to reduce energy use in low-rise buildings in hot climates. EPRA Int. J. Multidiscipl. Res. (IJMR) 10(6), 522–526 (2024).

    Google Scholar 

  31. Fallahpour, M., Naeini, H. G. & Mirzaei, P. A. Generic geometrical parametric study of wind-driven natural ventilation to improve indoor air quality and air exchange in offices. J. Build. Eng. 84, 108528 (2024).

    Google Scholar 

  32. Yamanaka, T. et al. Natural, wind-forced ventilation caused by turbulence in a room with a single opening. Int. J. Vent. 5(1), 179–187 (2006).

    Google Scholar 

  33. Cockroft, J. & Robertson, P. Ventilation of an enclosure through a single opening. Build. Environ. 11(1), 29–35 (1976).

    Google Scholar 

  34. Warren, P., Ventilation through openings on one wall only, Energy conservation in heating, cooling, and ventilating buildings. In Heat and mass transfer techniques and alternatives (1978).

  35. Linden, P., Lane-Serff, G. & Smeed, D. Emptying filling boxes: The fluid mechanics of natural ventilation. J. Fluid Mech. 212, 309–335 (1990).

    Google Scholar 

  36. Chen, Z., Li, Y. & Mahoney, J. Natural ventilation in an enclosure induced by a heat source distributed uniformly over a vertical wall. Build. Environ. 36(4), 493–501 (2001).

    Google Scholar 

  37. Fitzgerald, S. D. & Woods, A. W. Natural ventilation of a room with vents at multiple levels. Build. Environ. 39(5), 505–521 (2004).

    Google Scholar 

  38. Rossini, F.D. & K. Li, Selected values of physical and thermodynamic properties of hydrocarbons and related compounds: comprising the tables of the American petroleum institute research Project 44 extant as of December 31, 1952. (No Title), (1953).

  39. Vélez, C., Khayet, M. & De Zárate, J. O. Temperature-dependent thermal properties of solid/liquid phase change even-numbered n-alkanes: n-Hexadecane, n-octadecane and n-eicosane. Appl. Energy 143, 383–394 (2015).

    Google Scholar 

  40. Bi, Y. et al. Influences of additives on the gas hydrate cool storage process in a new gas hydrate cool storage system. Energy Convers. Manag. 47(18–19), 2974–2982 (2006).

    Google Scholar 

  41. Yakhot, V. & Orszag, S. A. Renormalization group analysis of turbulence. I. basic theory. J. Sci. Comput. 1(1), 3–51 (1986).

    Google Scholar 

  42. Mahdi, J. M. et al. Accelerated melting of PCM in energy storage systems via novel configuration of fins in the triplex-tube heat exchanger. Int. J. Heat Mass Transfer 124, 663–676 (2018).

    Google Scholar 

  43. Loveday, D. & Taki, A. Convective heat transfer coefficients at a plane surface on a full-scale building facade. Int. J. Heat Mass Transfer 39(8), 1729–1742 (1996).

    Google Scholar 

  44. Guo, Z.-Y., Tao, W.-Q. & Shah, R. The Field Synergy (coordination) Principle and its applications in enhancing single phase convective heat transfer. Int. J. Heat Mass Transfer 48(9), 1797–1807 (2005).

    Google Scholar 

  45. Zhao, X. et al. A review on heat enhancement in thermal energy conversion and management using field synergy principle. Appl. Energy 257, 113995 (2020).

    Google Scholar 

  46. Li, F., Zhu, W. & He, H. Numerical optimization on microchannel flow and heat transfer performance based on field synergy principle. Int. J. Heat Mass Transfer 130, 375–385 (2019).

    Google Scholar 

  47. Guo, Z., Li, D. & Wang, B. A novel concept for convective heat transfer enhancement. Int. J. Heat Mass Transfer 41(14), 2221–2225 (1998).

    Google Scholar 

  48. Tao, W.-Q., Guo, Z.-Y. & Wang, B.-X. Field Synergy Principle for enhancing convective heat transfer––its extension and numerical verifications. Int. J. Heat Mass Transfer 45(18), 3849–3856 (2002).

    Google Scholar 

  49. Rydberg, J., Norback, P. & Stockholm, S. Air distribution and draft. ASHVE Trans. 55, 225 (1949).

    Google Scholar 

  50. Koestel, A. Performance and evaluation of room air distribution systems. ASHRAE Transact. 61, (1955).

  51. Toulouse, M.-L., Analyse et caractérisation de la convection naturelle et de la convection mixte dans des enceintes confinées. In Toulouse, ENSAE (2004).

  52. Arasu, A. V. & Mujumdar, A. S. Numerical study on melting of paraffin wax with Al2O3 in a square enclosure. Int. Commun. Heat Mass Transf. 39(1), 8–16 (2012).

    Google Scholar 

  53. Jacob, J. et al. Economic analysis of phase change material integrated photovoltaic thermal systems: A short communication. In IOP Conference Series: Earth and Environmental Science (IOP Publishing, 2023).

    Google Scholar 

  54. Jha, S. K. et al. Incorporation of phase change materials in buildings. Constr. Mater. 4(4), 676–703 (2024).

    Google Scholar 

  55. Ahmad, A. & Memon, S. A. A novel method to evaluate phase change materials’ impact on buildings’ energy, economic, and environmental performance via controlled natural ventilation. Appl. Energy 353, 122033 (2024).

    Google Scholar 

  56. Zhang, L. et al. Energy, economic and environmental (3E) analysis of residential building walls enhanced with phase change materials. J. Build. Eng. 84, 108503 (2024).

    Google Scholar 

  57. UK, F. Fisher UK. Available from: https://www.fishersci.fi/shop/products/n-eicosane-99-thermo-scientific/11431518.

  58. Faouzi, A. et al. Enhancing natural ventilation in buildings with double-pass inclined solar chimneys: A sustainable solution. Stud. Eng. Exact Sci. 5(2), e11663–e11663 (2024).

    Google Scholar 

  59. Ayoobi, A. W., Ekimci, B. G. & Inceoğlu, M. A comparative study of sustainable cooling approaches: Evaluating the performance of natural ventilation strategies in arid and semi-arid regions. Building. 14(12), 3995 (2024).

    Google Scholar 

Download references

Funding

Open access funding provided by Budapest University of Technology and Economics. This work was supported by the János Bolyai Research Scholarship of the Hungarian Academy of Sciences (BO/00059/23/6) and by the Hungarian Scientific Research Fund (NKFIH FK-142204).

Author information

Authors and Affiliations

  1. Department of Mechanical Engineering, Faculty of Sciences and Applied Sciences, University of Larbi Ben Mhidi, Oum El Bouaghi, Algeria

    Moussa Aidi, Yamina Harnane & Lyes Bordja

  2. Laboratory of Advanced Design and Modeling of Mechanical Systems and Thermo-Fluid (CMASMTF), University of Larbi Ben Mhidi, Oum El Bouaghi, Algeria

    Moussa Aidi, Yamina Harnane & Lyes Bordja

  3. Mechanical Engineering Department, Engineering Faculty, Kocaeli University, Kabaoğlu, Umuttepe Yerleşkesi, İzmit/Kocaeli, 41380, Turkey

    Müslüm Arıcı

  4. Department of Building Services and Process Engineering, Faculty of Mechanical Engineering, Budapest University of Technology and Economics, Műegyetem rkp. 3, Budapest, H-1111, Hungary

    Tibor Poós

Authors
  1. Moussa Aidi
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  2. Yamina Harnane
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  3. Müslüm Arıcı
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  4. Lyes Bordja
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  5. Tibor Poós
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Contributions

M. A. and Y. H. conceived the study and performed the numerical simulations. L. B. contributed to the data analysis and interpretation of the results. M. A. contributed to the methodology development and critical technical input. T. P. supervised the research, contributed to the interpretation of the results, and revised the manuscript. All authors reviewed and approved the final manuscript.

Corresponding author

Correspondence to Tibor Poós.

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Aidi, M., Harnane, Y., Arıcı, M. et al. Thermal comfort enhancement in Oum El Bouaghi (Algeria) using PCM-enhanced walls and natural ventilation: a comparative CFD study. Sci Rep (2026). https://doi.org/10.1038/s41598-026-43308-y

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  • Received: 07 January 2026

  • Accepted: 03 March 2026

  • Published: 25 March 2026

  • DOI: https://doi.org/10.1038/s41598-026-43308-y

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Keywords

  • Phase change material
  • Ventilation strategies
  • Thermal comfort
  • Effective draft temperature
  • Synergy
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