Thermal behavior of alternative materials used as roof and efficiency of the reflective painting on the external face

Almeida, Eduardo Alves de; Passini, Roberta

doi:10.17533/udea.redin.n82a09

Cited by 1 publication

(3 citation statements)

References 19 publications

(20 reference statements)

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“…White painting on the external cover surface (VFBW) promoted a reduction of 10.4% of EST and 9.9% of IST when compared with the same type of cover without the white painting at the external surface (VFB), equaling the results of VFBW with PVC cover (better material in this research). Similar results were verified by Almeida and Passini (2017) being reported a reduction of 30.7% in the EST and 21% in the IST between VFB and VFBW, showing the effectiveness of white paint in the low absorption of the energy from solar radiation. Hashemi (2017) and Venkiteswaran et al (2017) highlighted that painting the upper face of the roof with white color is an effective strategy to improve roof thermal insulation, improving the thermal environment through a decrease of solar radiation absorptance.…”

Section: Discussionsupporting

confidence: 86%

“…There were observed the highest means of EST (34.66°C) and IST (31.52°C) at VFB treatment, being these values approximately 21.5% (EST) and 17.2% (IST) greater than the observed for PVC (best results). The worse response of VFB cover verified in this research was previously reported by Almeida and Passini (2017) that verified higher values of EST and IST for this kind of cover when compared include the other kinds of evaluated materials (asbestos cement, bamboo, bamboo painted in white, and VFBW). The worse response verified at VFB can be explained by the dark color in the upper surface of the cover; this dark color is responsible to imbibe a great quantity of energy from solar radiation.…”

Section: Discussionsupporting

confidence: 79%

“…1), a fact that attests to the efficiency of this kind of cover materials in the decrease of solar energy absorption. These results are corroborated by Almeida and Passini (2017) and Almeida et al (2018), being verified by the authors higher EST and IST values next to 12:00 pm and lowest values in the beginning and at the end of the day. Frederick (2017), when studying the variation in groundlevel irradiance under clear skies, verified the maximum irradiance at 12:00 pm, a fact that explains the higher IST and EST observed in this study.…”

Section: Discussionsupporting

confidence: 68%

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Thermal environment in mobile shelters with different cover types used for chicken housing at the semi-extensive rearing system

et al. 2020

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In tropical climate countries, animal production faces a huge challenge, being the high solar irradiation levels an important factor that negatively influences the welfare and animal performance. The purpose of this research was to check the environment inside mobile shelters with different kinds of cover materials. This research has been developed at the State University of Goiás, Brazil, being used four different cover materials: DFPC, double-faced plastic canvas; PVC, polyvinyl chloride; VFB, tiles made with vegetable fiber and bitumen; and VFBW, tiles made with vegetable fiber and bitumen being the outer face painted white. Covers were placed up mobile shelters with the following dimensions: 1 m length × 1 m width × 1 m height and cover pitch of 30°. The environment was evaluated through thermal comfort indexes: enthalpy (H), temperature and humidity index (THI), black globe and humidity index (BGHI), mean radiant temperature (MRT) and thermal heat load (THL), and the measurement of thermal environmental variables (temperature of external (EST) and internal (IST) surface of the cover, dry bulb temperature (T db ), black globe temperature (T bg ), relative humidity (RH), and wind speedy (WS)). Data analysis was performed using PROC MIXED of SAS® by analysis of variance (ANOVA), followed by the Tukey test, at 5% of significance level. There was observed beneficial effect of the usage of shading, with a decrease in air temperature and thermal comfort indexes when compared with the unshaded environment. The materials presented different thermal behavior, with better results for PVC and VFBW, that presented lower internal (IST) and external surface temperature (EST), in addition to lower black globe temperature, thermal heat load, and black globe and humidity index. PVC and VFBW were the best types of covers evaluated, with significant decreased thermal comfort indexes.

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Section: Discussionsupporting

confidence: 86%

Section: Discussionsupporting

confidence: 79%