Hygrothermal Performance of Cool Roofs Subjected to Saudi Climates

In regions with hot climatic conditions such as that in Saudi Arabia, a substantial share of energy is used for cooling the buildings. Many studies have shown that cool (white) roofs can help reduce the cooling energy load and thus the demand for energy over time. Also, cool roofs help reduce the ur...

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Main Authors: Hamed H. Saber, Wahid Maref, Ali E. Hajiah
Format: Article
Language:English
Published: Frontiers Media S.A. 2019-04-01
Series:Frontiers in Energy Research
Subjects:
Online Access:https://www.frontiersin.org/article/10.3389/fenrg.2019.00039/full
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author Hamed H. Saber
Wahid Maref
Ali E. Hajiah
author_facet Hamed H. Saber
Wahid Maref
Ali E. Hajiah
author_sort Hamed H. Saber
collection DOAJ
description In regions with hot climatic conditions such as that in Saudi Arabia, a substantial share of energy is used for cooling the buildings. Many studies have shown that cool (white) roofs can help reduce the cooling energy load and thus the demand for energy over time. Also, cool roofs help reduce the urban heat island during the summer time. This research study focused on determining: (a) whether cool roofs lead to risk of condensation and mold growth in Saudi climates, (b) the amount of energy savings as result of using cool roofs instead of black roofs of same insulation amount, and (c) the reduction in the amount of insulation in cool roof having the same energy performance level as the black roof. As such, numerical simulations were conducted for a roofing system that is commonly used in low-rise buildings in Saudi Arabia in order to asses and compare the energy and hygrothermal performance of cool and black roofs. The roof was subjected to weather conditions of the Eastern Province of Saudi Arabia. The indoor conditions were taken based simple method of ASHRAE Standard 160. The results showed no moisture accumulation occurred from year-to-year after 6 years and 7 years for the black roof and cool roof, respectively, and the highest relative humidities in the black and cool roofs were well below 80% resulting in no risk of condensation and mold growth occurred in these roofs. The main outcome of this study has shown the capabilities of using reflective materials with different short-wave solar absorption coefficients for enhancing the energy performance of roofs and/or reducing the amount of insulation that resulted in same energy performance as black roofs. This study can be used in future for upgrading the Saudi Building Code so as to allow less roof insulation if cool roof is installed.
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spelling doaj.art-4f2114b25cbe482d9ff01819b50d72802022-12-21T19:34:14ZengFrontiers Media S.A.Frontiers in Energy Research2296-598X2019-04-01710.3389/fenrg.2019.00039433301Hygrothermal Performance of Cool Roofs Subjected to Saudi ClimatesHamed H. Saber0Wahid Maref1Ali E. Hajiah2Department of Mechanical Engineering, Jubail University College, Royal Commission of Jubail and Yanbu, Jubail, Saudi ArabiaDepartment of Construction Engineering, École de Technologie Supérieure, University of Quebec, Montreal, QC, CanadaEnergy and Building Research Center, Kuwait Institute for Scientific Research, Shuwaikh, KuwaitIn regions with hot climatic conditions such as that in Saudi Arabia, a substantial share of energy is used for cooling the buildings. Many studies have shown that cool (white) roofs can help reduce the cooling energy load and thus the demand for energy over time. Also, cool roofs help reduce the urban heat island during the summer time. This research study focused on determining: (a) whether cool roofs lead to risk of condensation and mold growth in Saudi climates, (b) the amount of energy savings as result of using cool roofs instead of black roofs of same insulation amount, and (c) the reduction in the amount of insulation in cool roof having the same energy performance level as the black roof. As such, numerical simulations were conducted for a roofing system that is commonly used in low-rise buildings in Saudi Arabia in order to asses and compare the energy and hygrothermal performance of cool and black roofs. The roof was subjected to weather conditions of the Eastern Province of Saudi Arabia. The indoor conditions were taken based simple method of ASHRAE Standard 160. The results showed no moisture accumulation occurred from year-to-year after 6 years and 7 years for the black roof and cool roof, respectively, and the highest relative humidities in the black and cool roofs were well below 80% resulting in no risk of condensation and mold growth occurred in these roofs. The main outcome of this study has shown the capabilities of using reflective materials with different short-wave solar absorption coefficients for enhancing the energy performance of roofs and/or reducing the amount of insulation that resulted in same energy performance as black roofs. This study can be used in future for upgrading the Saudi Building Code so as to allow less roof insulation if cool roof is installed.https://www.frontiersin.org/article/10.3389/fenrg.2019.00039/fullcool roofsgreen roofsblack roofsenergy savingsmoisture accumulationhygrothermal performance
spellingShingle Hamed H. Saber
Wahid Maref
Ali E. Hajiah
Hygrothermal Performance of Cool Roofs Subjected to Saudi Climates
Frontiers in Energy Research
cool roofs
green roofs
black roofs
energy savings
moisture accumulation
hygrothermal performance
title Hygrothermal Performance of Cool Roofs Subjected to Saudi Climates
title_full Hygrothermal Performance of Cool Roofs Subjected to Saudi Climates
title_fullStr Hygrothermal Performance of Cool Roofs Subjected to Saudi Climates
title_full_unstemmed Hygrothermal Performance of Cool Roofs Subjected to Saudi Climates
title_short Hygrothermal Performance of Cool Roofs Subjected to Saudi Climates
title_sort hygrothermal performance of cool roofs subjected to saudi climates
topic cool roofs
green roofs
black roofs
energy savings
moisture accumulation
hygrothermal performance
url https://www.frontiersin.org/article/10.3389/fenrg.2019.00039/full
work_keys_str_mv AT hamedhsaber hygrothermalperformanceofcoolroofssubjectedtosaudiclimates
AT wahidmaref hygrothermalperformanceofcoolroofssubjectedtosaudiclimates
AT aliehajiah hygrothermalperformanceofcoolroofssubjectedtosaudiclimates