Thermal Performance of a Concrete Cool Roof under Different Climatic Conditions of Mexico

Many parts of the building envelopes contain enclosed airspaces. Also, the insulating glass units in fenestration systems, such as curtain walls, windows, and skylight devices, contain enclosed spaces that are normally filled with air or heavy gas such as argon, xenon, or krypton. The thermal resistance (R-value) of an enclosed space depends mainly on the type of the filling gas, emissivity of all surfaces that bound the space, the size and orientation of the space, the direction of heat flow through the space, and the respective temperatures of all surfaces that define the space. Assessing the energy performance of building envelopes and fenestration systems, subjected to different climatic conditions, requires accurate determination of the R-values of the enclosed spaces. In this study, a comprehensive review is conducted on the thermal performance of enclosed airspaces for different building applications. This review includes the computational and experimental methods for determining the effective R-value of enclosed reflective airspaces. Also, the different parameters that affect the thermal performance of enclosed airspaces are discussed. These parameters include the following: (a) dimensions, (b) inclination angles, (c) directions of heat flow, (d) emissivity of all surfaces that bound the space, and (e) operating conditions. Moreover, numerical simulations are conducted using a previously developed and validated model to investigate the effect of the inclination angle, direction of heat transfer, and the coating emissivity on the R-values of enclosed spaces when they are filled with different types of gases.

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Reducing cooling demands in a hot dry climate: A simulation study for non-insulated passive cool roof thermal performance in residential buildings

Energy and Buildings ◽

10.1016/j.enbuild.2014.12.034 ◽

2015 ◽

Vol 89 ◽

pp. 142-152 ◽

Cited By ~ 61

Author(s):

Marwa Dabaieh ◽

Omar Wanas ◽

Mohamed Amer Hegazy ◽

Erik Johansson

Keyword(s):

Thermal Performance ◽

Simulation Study ◽

Residential Buildings ◽

Cool Roof ◽

Passive Cool

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Thermal performance of an insulated roof with reflective insulation: Field tests under hot climatic conditions

Journal of Building Physics ◽

10.1177/1744259112448181 ◽

2012 ◽

Vol 36 (3) ◽

pp. 229-246 ◽

Cited By ~ 20

Author(s):

Marco D’Orazio ◽

Costanzo Di Perna ◽

Elisa Di Giuseppe ◽

Matteo Morodo

Keyword(s):

Thermal Performance ◽

Field Tests ◽

Climatic Conditions

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Thermal performance analysis of a naturally ventilated system using PMV models for different roof inclinations in composite climatic conditions

Journal of the Brazilian Society of Mechanical Sciences and Engineering ◽

10.1007/s40430-020-2219-4 ◽

2020 ◽

Vol 42 (3) ◽

Cited By ~ 1

Author(s):

Yatharth Vaishnani ◽

Sana Fatima Ali ◽

Aditya Joshi ◽

Dibakar Rakshit ◽

Fujen Wang

Keyword(s):

Performance Analysis ◽

Thermal Performance ◽

Climatic Conditions

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Development of PCM cool roof system to control urban heat island considering temperate climatic conditions

Energy and Buildings ◽

10.1016/j.enbuild.2015.12.056 ◽

2016 ◽

Vol 116 ◽

pp. 341-348 ◽

Cited By ~ 37

Author(s):

Min Hee Chung ◽

Jin Chul Park

Keyword(s):

Urban Heat Island ◽

Climatic Conditions ◽

Heat Island ◽

Roof System ◽

Cool Roof ◽

Urban Heat

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Simulation of Thermal Performance and Cost Benefits of Cool Roof Options through Building Engineering System Software

Mehran University Research Journal of Engineering and Technology ◽

10.22581/muet1982.2004.13 ◽

2020 ◽

Vol 39 (4) ◽

pp. 806-814

Author(s):

Aftab Ahmed Sahito ◽

Rizwan Ahmed Memon ◽

Khanji Harijan ◽

Pervez Hameed Shaikh

Keyword(s):

Air Temperature ◽

Thermal Performance ◽

Temperature Difference ◽

Energy Savings ◽

Payback Period ◽

Engineering System ◽

Cool Roof ◽

Cost Benefits ◽

Save Energy ◽

Building Engineering

The cool roofs in buildings is a promising option to deal with summer Urban Heat Island (UHI) effects. In context to that, studies on different cool roof materials are widely available; however, there is a dearth of studies on insulating material benefits and implication for tropical and sub-tropical climate zones. This work investigates thermal performance, energy savings and cost benefits of cool roof materials. For this study, simulation of various cool roof materials such as Marble, Expanded Polyurethane Spray (EPS), Poly Vinyl Chloride (PVC), Spray Polyurethane Foam (SPF) , Extruded Polystyrene Foam (XPS), Thermocol sheet, Asphalt tile, Gypsum tile and Jumbolon-board have been carried out using Energy Plus software package. The results of zone air temperature show that maximum zone air temperature occurs in the month of May. The maximum zone air temperature obtained for conventional roof is 32.1oC, whereas that for Thermocol sheet, SPF, XPS, Jumbolon-board, EPS, marble, PVC, Asphalt tile and Gypsum tile is 28.8, 28.9, 28.8, 29, 29.1, 31.9, 30.5, 30.2 and 30.7oC respectively. Conventional roof surface outside and inside temperature difference is 2.90C, whereas, roof surface outside and inside temperature difference for Thermocol sheet, XPS, Jumbolon-board, SPF, EPS, marble, PVC, asphalt tile and gypsum tile is 9.2, 9.3, 8.7, 7.5, 8.1, 3, 3.1, 3.3 and 2.20C, respectively. Notably, XPS, Thermocol sheet, SPF, Jumbolon-board, EPS, Marble, PVC, Asphalt tile and Gypsum tile cool roof materials can save around 5.47, 5.38, 5.35, 5.15, 4.93, 1.09, 2.62, 2.31 and 2.18 MWh annually, respectively for the selected building. The payback period for marble, PVC, gypsum tile and asphalt tile is above 1 year, whereas the effective payback period obtained for XPS, Thermocol sheet, SPF, EPS and Jumbolon-board varies from 3 to 6 months. It is concluded that the cool roof materials may be used effectively to save energy and cost.

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Comparative Analysis of the Use of Thermal Insulation Materials Depending on Climatic Conditions and Comfort Microclimate Supply Systems

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.906.99 ◽

2022 ◽

Vol 906 ◽

pp. 99-106

Author(s):

Siranush Egnatosyan ◽

David Hakobyan ◽

Spartak Sargsyan

Keyword(s):

Energy Efficiency ◽

Comparative Analysis ◽

Thermal Insulation ◽

Thermal Performance ◽

Climatic Conditions ◽

Insulation Material ◽

Insulation Layer ◽

Transfer Resistance ◽

Insulation Materials ◽

Wide Range

The use of thermal insulation materials to reduce the heating and cooling demand of the building in order to provide energy efficiency is the main solution. But there is a wide range of these products on the market and, therefore, the choice and application of these materials is a rather difficult task, since many factors must be taken into account, such as environmental safety, cost, durability, climatic conditions, application technology, etc. Basically, comfort microclimate systems are designed based on normative standards, where the thickness of the thermal insulation material is selected depending on the required heat transfer resistance. These values are calculated taking into account climate conditions, that is the duration of the heating period, as well as taking into account sanitary and hygienic requirements. This article discusses the thermal performance of building materials, and also provides a comparative analysis of the use of thermal insulation materials depending on climatic factors and on the system providing comfort microclimate. Based on the calculations by mathematical modeling and optimization, it is advisable to choose the thickness of the thermal insulation, taking into account the capital and operating costs of the comfort microclimate systems. Comparing the optimization data with the normative one, the energy efficiency of the building increases by 50-70% when applying the optimal thickness of the thermal insulation layer, and when the thermal insulation layer is increased, the thermal performance of the enclosing structures has improved by 30%, which contributes to energy saving.

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