Numerical Investigation of Roofing Materials Effect on Solar Heat Gain in Different External Conditions
In this study, the thermal performance of three kinds of roofs with different heat capacity and thermal conductivity under different external conditions has been investigated using a numerical method. For this purpose, the combined solar radiation, conduction and convection heat transfer were calcul...
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| Format: | Article |
| Language: | English |
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Semnan University
2019-05-01
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| Series: | Journal of Heat and Mass Transfer Research |
| Subjects: | |
| Online Access: | https://jhmtr.semnan.ac.ir/article_3155_64adea8e6b462ce96bc6192993802138.pdf |
| _version_ | 1797259673734217728 |
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| author | Milad Mahmoodzadeh Rouhollah Fatehi |
| author_facet | Milad Mahmoodzadeh Rouhollah Fatehi |
| author_sort | Milad Mahmoodzadeh |
| collection | DOAJ |
| description | In this study, the thermal performance of three kinds of roofs with different heat capacity and thermal conductivity under different external conditions has been investigated using a numerical method. For this purpose, the combined solar radiation, conduction and convection heat transfer were calculated implicitly in terms of a one-dimensional finite difference method. Different high and low solar radiation conditions in two common climates in the Middle East, including hot-humid and hot-dry, were considered. The effect of roofing materials was investigated in terms of their thermal storage and overall heat transfer coefficient. Moreover, the time lags and decrement factors were evaluated to compare the performance of the roof. The numerical model has been validated using EnergyPlus. The results indicate that the roof with high thermal storage and low thermal conductivity has better performance in comparison to others. However, the total heat gains are not linearly proportional to the overall heat transfer coefficients, e.g. here, the ratios of a total load of roof 1 to roofs 2 and 3 are about 12 percent lower than the ratio of overall heat transfer coefficients. Furthermore, the solar radiation intensity had considerable effects on time lags. Finally, it can be concluded that the external conditions have no significant effect on the decrement factor. |
| first_indexed | 2024-04-24T23:13:10Z |
| format | Article |
| id | doaj.art-eb965572460e4ea3b30abeff5e53b372 |
| institution | Directory Open Access Journal |
| issn | 2345-508X 2383-3068 |
| language | English |
| last_indexed | 2024-04-24T23:13:10Z |
| publishDate | 2019-05-01 |
| publisher | Semnan University |
| record_format | Article |
| series | Journal of Heat and Mass Transfer Research |
| spelling | doaj.art-eb965572460e4ea3b30abeff5e53b3722024-03-17T08:03:22ZengSemnan UniversityJournal of Heat and Mass Transfer Research2345-508X2383-30682019-05-0161415310.22075/jhmtr.2018.3059.11433155Numerical Investigation of Roofing Materials Effect on Solar Heat Gain in Different External ConditionsMilad Mahmoodzadeh0Rouhollah Fatehi1Department of Mechanical Engineering, University of Victoria, Victoria, CanadaPersian Gulf UniversityIn this study, the thermal performance of three kinds of roofs with different heat capacity and thermal conductivity under different external conditions has been investigated using a numerical method. For this purpose, the combined solar radiation, conduction and convection heat transfer were calculated implicitly in terms of a one-dimensional finite difference method. Different high and low solar radiation conditions in two common climates in the Middle East, including hot-humid and hot-dry, were considered. The effect of roofing materials was investigated in terms of their thermal storage and overall heat transfer coefficient. Moreover, the time lags and decrement factors were evaluated to compare the performance of the roof. The numerical model has been validated using EnergyPlus. The results indicate that the roof with high thermal storage and low thermal conductivity has better performance in comparison to others. However, the total heat gains are not linearly proportional to the overall heat transfer coefficients, e.g. here, the ratios of a total load of roof 1 to roofs 2 and 3 are about 12 percent lower than the ratio of overall heat transfer coefficients. Furthermore, the solar radiation intensity had considerable effects on time lags. Finally, it can be concluded that the external conditions have no significant effect on the decrement factor.https://jhmtr.semnan.ac.ir/article_3155_64adea8e6b462ce96bc6192993802138.pdfroofing materialsthermal storageheat gaincooling loadtime lags |
| spellingShingle | Milad Mahmoodzadeh Rouhollah Fatehi Numerical Investigation of Roofing Materials Effect on Solar Heat Gain in Different External Conditions Journal of Heat and Mass Transfer Research roofing materials thermal storage heat gain cooling load time lags |
| title | Numerical Investigation of Roofing Materials Effect on Solar Heat Gain in Different External Conditions |
| title_full | Numerical Investigation of Roofing Materials Effect on Solar Heat Gain in Different External Conditions |
| title_fullStr | Numerical Investigation of Roofing Materials Effect on Solar Heat Gain in Different External Conditions |
| title_full_unstemmed | Numerical Investigation of Roofing Materials Effect on Solar Heat Gain in Different External Conditions |
| title_short | Numerical Investigation of Roofing Materials Effect on Solar Heat Gain in Different External Conditions |
| title_sort | numerical investigation of roofing materials effect on solar heat gain in different external conditions |
| topic | roofing materials thermal storage heat gain cooling load time lags |
| url | https://jhmtr.semnan.ac.ir/article_3155_64adea8e6b462ce96bc6192993802138.pdf |
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