Thermal-Energy Performance of Bulk Insulation Coupled with High-Albedo Roof Tiles in Urban Pitched Residential Roof Assemblies in the Hot, Humid Climate

Syed Ahmad Farhan,Hashem Al-Mattarneh,Mohammed Dahim,Nasir Shafiq,Rabah Ismail

doi:10.3390/su14052867

Syed Ahmad Farhan, Hashem Al-Mattarneh + Show 3 more

Open Access

https://doi.org/10.3390/su14052867

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Abstract

The high rate of heat transfer through the residential roof assembly aggravates the condition of indoor thermal discomfort. Bulk insulation can be installed in the assembly to improve thermal performance. However, although it can efficiently reduce diurnal heat transfer from the outdoor environment into the indoor space through the roof assembly, it can also suppress nocturnal heat transfer in the opposite direction. Alternatively, high-albedo roof tiles employ cool colors to reflect heat at the roof surface, whereas bulk insulation hinders the conduction of heat through the roof assembly. In light of the potential of high-albedo roof tiles and bulk insulation in reducing heat transfer, thermal-energy performance of an urban pitched residential roof assembly, which adopted varying configurations of high-albedo roof tiles and bulk insulation under a hot, humid climate, was evaluated. Energy savings were generated, which were 15.13% when the change from a conventional to a high-albedo roof surface was performed, and 17.00% when the installation of bulk insulation was performed on the high-albedo roof assembly.

Highlights

Buildings in countries that have hot, humid climates are exposed to intense solar radiation during the day, owing to the high altitude of the sun path [1,2]
The test cells are exposed to a hot, humid climate throughout the year quently, themean test cells exposedannual-averaged to a hot, humid profiles climate throughout the year
Installation of bulk insulation within the high-albedo roof assembly has led to further reduction in roof surface temperature throughout the diurnal segment

Summary

Introduction

Buildings in countries that have hot, humid climates are exposed to intense solar radiation during the day, owing to the high altitude of the sun path [1,2]. The roof receives the highest amount of solar radiation in comparison to other components of the building envelope by virtue of the horizontal orientation and higher elevation of the roof [3,4]. Malaysia, which is located in Southeast Asia from 1◦ to 7◦ north of the equator [1], has a hot, humid climate throughout the year [1,5]. Its climate can be classified as a tropical rainforest climate, as per the Köppen–Geiger climate classification [6]. Kota Kinabalu, Kuantan, Kuching, Malacca and Subang Jaya, mean daily temperatures of Malaysia, from 1956 to 2016, ranged between 25.0 ◦ C and 28.7 ◦ C.

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