Consideration of the effect of inhomogeneities in the wall panel on the value of heat transfer resistance

Introduction. Modern requirements for improving the energy efficiency of life and reducing energy consumption of buildings in general dictate the development of new modern structures with high thermal protection and strength characteristics. Structures of this type include multilayer wall panels with a filler made of various highly effective thermal insulation materials. The analysis of the effectiveness of the decisions taken on the use of mineral wool fillers in a two-layer wall panel with different thickness of the outer insulation layer is carried out.

Materials and methods. The current regulatory documents regarding the provision of thermal protection of enclosing structures were used. The calculations were carried out using numerical modelling in the COMSOL Multiphysics software package, as well as by the analytical calculation method presented in the normative literature.

Results. The variants of the facade wall arrangement with different thicknesses of the external insulation layer in combination with a two-layer wall panel are considered. By conducting numerical modelling, the character of temperature distribution along the thickness of the wall panel structure under consideration is established. The analysis of the influence of inhomogeneous thermal inclusions on the equivalent heat transfer resistance of a two-layer wall panel is carried out.

Conclusions. The results of the engineering and analytical calculation of the equivalent heat transfer resistance of a two-layer wall panel, as well as numerical modelling in the COMSOL Multiphysics software package, allow to obtain an updated value of the heat transfer resistance of a two-layer wall panel, which helps to determine the minimum thickness of the outer insulation layer depending on the climatic zone of construction. The use of mineral wool fillers in the construction of double-layer wall panels increases the equivalent heat transfer resistance of the enclosing structure. An example of calculation of the equivalent heat transfer resistance of a two-layer wall panel is given, which makes it possible to determine more accurately the minimum thickness of the outer insulation layer. The proposed calculation method allows to reduce significantly the cost per unit area of the wall panel when organizing the insulation of the facade of a residential building.

1. Kuzmina T.K., Avetisyan R.T., Mirzakhanova A.T. Features of the construction of buildings from large-sized modules. Proceedings of the TSU. 2022; 5:95-101. DOI: 10.24412/2071-6168-2022-5-95-102. EDN RISDVD. (rus.).

2. Shi Y., Zhang Y., Ni K., Liu W., Luo Y. Research and practices of large composite external wall panels for energy saving prefabricated buildings. MATEC Web of Conferences. 2019; 289:10012. DOI: 10.1051/matecconf/201928910012

3. Chen Z., Jiang L., Xiao M., Hu Y., Huang S. Rapid construction of modular buildings for emergencies: a case study from Hong Kong, China. Proceedings of the Institution of Civil Engineers — Civil Engineering. 2023; 176(2):65-72. DOI: 10.1680/jcien.22.00172

4. Smoliy V.A., Kosarev A.S., Yatsenko E.A. Efficiency of using energy-saving three-layer panels for residential and public frame-panel housing construction. Central Scientific Bulletin. 2018; 3(15-16):(56-57):47-50. EDN XYOFLV. (rus.).

5. Semikin P.V., Dolzhikov V.N. Efficient energy-saving wall panels. Creativity and Modernity. 2016; 1(1):65-76. EDN YURSCX. (rus.).

6. Khaleghi H., Karatas A. Arctic architectures: unleashing energy efficiency and resilience in extreme cold regions. Proceedings of International Structural Engineering and Construction. 2023; 10(1). DOI: 10.14455/ISEC.2023.10(1).SUS-24

7. Matveev A.V., Ovchinnikov A.A. Development of energy-efficient large-panel enclosing structures. Housing Construction. 2014; 10:19-23. EDN STWXOX. (rus.).

8. Nazirov R.A., Belov T.V. Influence resistance heat insulant distribution of temperature fields in wall fences ventilated facades. Journal of Siberian Federal University. Engineering & Technologies. 2014; 7(2):207-213. EDN SBYPBF. (rus.).

9. Davidyuk A.A. Assessment of the influence of heat-conducting inclusions on the reduced heat transfer resistance of external multilayer walls based on lightweight concrete with glassy fillers. Housing Construction. 2014; 7:24-27. EDN SHORXZ. (rus.).

10. Shchekin R.V., Korenevsky S.M., Bem G.E. Handbook of heat supply and ventilation. Book two. Ventilation and air conditioning. 4th ed., revised and additional. Kyiv, Budivelnik, 1976; 416. (rus.).

11. Pastushkov P.P., Gagarin V.G., Pavlenko N.V. Methodological manual for assigning calculated thermal performance indicators of building materials and products. Moscow, FAU “FCS”, 2019. (rus.).

12. Pastushkov P.P. On the problems of determining the thermal conductivity of building materials. Construction Materials. 2019; 4:57-64. DOI: 10.31659/0585-430X-2019-769-4-57-63. EDN SDSOJK. (rus.).

13. Gagarin V.G., Pastushkov P.P. Changes in the time of thermal conductivity of gas-filled polymer thermal insulation materials. Construction Materials. 2017; 6:28-31. EDN YUNGSX. (rus.).

14. Samarin O.D., Polyakova M.Z. Dependence of thermal uniformity of external walls of residential buildings on their geometric characteristics and climatic parameters. Plumbing, Heating, Air-Conditioning. 2020; 3(219):52-54. EDN KJAEYL. (rus.).

15. Grünbauer H.J. M., Bicerano J., Clavel P., Daussin R.D., de Vos H.A., Elwell M.J. et al. Rigid Polyurethane Foams. Polymeric Foams. 2004. DOI: 10.1201/9780203506141.ch7

16. Gagarin V.G., Pastushkov P.P. Quantitative assessment of the energy efficiency of energy-saving measures. Construction Materials. 2013; 6:7-9. EDN QIOMJZ. (rus.).

17. Jelle B.P. Traditional, state-of-the-art and future thermal building insulation materials and solutions — Properties, requirements and possibilities. Energy and Buildings. 2011; 43(10):2549-2563. DOI: 10.1016/j.enbuild.2011.05.015

18. Malyavina E.G., Frolova A.A. The influence climate features of the construction area on the economically favorable level thermal protection in office buildings. News of Higher Educational Institutions. Construction. 2020; 11(743):89-99. DOI: 10.32683/0536-1052-2020-743-11-89-99. EDN LSCNCN. (rus.).

19. Datciuk T.A., Grimitlin A.M., Anisimov S.M., Tsygankov A.V. Transmission and infiltration heat losses of residential buildings. Bulletin of Civil Engineers. 2021; 6(89):115-120. DOI: 10.23968/1999-5571-2021-18-6-115-120. EDN FAMYON. (rus.).

20. Xing D., Li N. Three-dimensional heat transfer of globe thermometers in indoor environments controlled by radiant systems. Building and Environment. 2021; 188:107505. DOI: 10.1016/j.buildenv.2020.107505

21. Suchilin V.A., Kochetkov A.S., Gubanov N.N. Modeling in COMSOL Multiphysics energy losses of housing and communal services structures depending on operating conditions. Plumbing, Heating, Air-Conditioning. 2019; 4(208):74-79. EDN SOJABE. (rus.).