Thermal performance evaluation of traditional walls and roof used in tropical climate using guarded hot box

Chowdhury, Debasish; Neogi, Subhasis

doi:10.1016/j.conbuildmat.2019.05.032

Cited by 34 publications

(13 citation statements)

References 17 publications

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“…Chowdhury and Neogi [36] investigated the thermal performance of common wall and roof constructions used in residential buildings in India using a guarded hot box facility.…”

Section: Literature Reviewmentioning

confidence: 99%

Construction and Calibration of a Unique Hot Box Apparatus

Alhawari

Mukhopadhyaya

2022

Energies

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A variety of mathematical models are available to estimate the thermal performance of buildings. Nevertheless, mathematical models predict the thermal performance of buildings that might differ from the actual performance. The hot box is a widely-used test apparatus to assess the actual thermal performance of various building envelope components (walls, roofs, windows) in the laboratory. This paper presents the process of designing, constructing, and calibrating a unique small-scale hot box apparatus. Despite its smaller metering area (1.0 m × 1.0 m), this apparatus met the key requirements (below ±0.25 °C fluctuations in chambers’ air temperature, and below 2.0% variation from the point-to-point temperature in reference to the temperature difference across the specimen) as prescribed in the ASTM C1363 and ISO 8990 standards. The walls of this apparatus are uniquely constructed using vacuum insulation panels or VIPs. The efficient and novel use of VIPs and workmanship during the construction of the apparatus are demonstrated through the temperature stability within the chambers. The achieved range of temperature steadiness below ±0.05 °C and point-to-point temperature variation below 1.0% of the temperature difference across the specimen allow for this apparatus to be considered unique among the calibrated hot box categories reported in the literature. In addition, having an affordable, simple-to-operate, and high-accuracy facility offers a great opportunity for researchers and practitioners to investigate new ideas and solutions. The apparatus was calibrated using two extruded polystyrene foam (XPS) specimens with thicknesses of 2″ and 4″. The calibration exercise indicates small differences between results obtained numerically, theoretically, and experimentally (below 3.0%). Ultimately, the apparatus was employed to measure the thermal properties of a specimen representing a lightweight steel framing (LSF) wall system, which is commonly used in cold climates. The results obtained experimentally were then compared to the ones estimated numerically using a 3D finite element modelling tool. The difference between the results obtained by both methods was below 9.0%.

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“…Chowdhury and Neogi [36] investigated the thermal performance of common wall and roof constructions used in residential buildings in India using a guarded hot box facility.…”

Section: Literature Reviewmentioning

confidence: 99%

Construction and Calibration of a Unique Hot Box Apparatus

Alhawari

Mukhopadhyaya

2022

Energies

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“…This method can be applied for the thermal characterization of homogeneous or non-homogeneous specimens and building structures or composite assemblies (e.g., walls with windows, doors). The GHB apparatus was used in several studies to evaluate the U-value of different construction elements, for instance, in References [23][24][25][26][27]. There were several data acquisition and measurement devices used in the hot box testing: 1.…”

Section: Measurements Of the U-value Of An Igu (Of A Window) In A Ghbmentioning

confidence: 99%

The Changes in Thermal Transmittance of Window Insulating Glass Units Depending on Outdoor Temperatures in Cold Climate Countries

et al. 2021

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Windows, which have a U-value that is governed by an insulating glass unit (IGU) U-value, must be a building’s only enclosure element, which has no design value concept. The declared U-value, which is calculated or measured with 0 °C of external ambient temperature, is used instead of the design value. For most of a building’s elements, its thermal transmittance with a decrease in the external temperature diminishes a little, i.e., improves. However, for modern window IGUs with Low-E coatings, it is the opposite: the thermal transmittance with a lowering external temperature increases. Therefore, for calculating the peak power for the heating of buildings it is necessary to pay attention to this phenomenon and, therefore, it would be wise to introduce the concept of design U-value for windows, recalculation rules, or affix their declared U-values. This is especially the case in modern times with the prevailing architectural tendencies for enlargement of transparent building elements. For IGUs with Low-E coatings and inert gas fillers, the thermal transmittance depends on the temperature difference between warm and cold environments. When the external temperature is −30 °C instead of 0 °C, the thermal transmittance of the IGU can increase by up to 35%. This study presents the thermal properties of windows’ IGUs depending on the changes in outdoor temperatures by using guarded a hot box climate chamber and presents the proposed simplified methodology for determining the thermal properties of windows’ glass units. The accuracy of the composed simplified methods, comparing the calculated thermal transmittances of IGUs with those measured in the “hot box”, were up to 1.25%.

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“…Chowdhury et al [3] used a Guarded Hot Box to explore the thermal characteristics of walls and roofs commonly used in Indian residential construction. Bai et al [4] integrated the numerical analyses carried out with the finite element method with experimental analyzes conducted in Hot Box to study the thermal properties of a wall made of hollow shale blocks.…”

Section: Introductionmentioning

confidence: 99%

Experimental analysis of insulating materials using Guarded Hot Box - Preliminary results

de Rubeis,

Ciccozzi,

Paoletti

et al. 2024

J. Phys.: Conf. Ser.

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The containment of energy consumption in the construction sector strongly depends on the envelope, which is mainly responsible for heat loss in buildings. Thus, great attention should be paid to the selection of thermally-performing materials. In this work, preliminary results of three different configurations of walls in real size have been compared, conducting the analyses with the heat flow meter method inside the Guarded Hot Box apparatus, capable of guaranteeing repeatable and controlled conditions. The analyses were carried out with two types of heat flow meters, characterized by different sensitivity. The side of the wall facing the hot chamber has been insulated with rock wool for all the experiments, while the other side has been insulated first with expanded polystyrene (EPS) with graphite, then with hemp, and finally with cork. The results showed that the sample with the best thermal behaviour is the first one, i.e., the wall with EPS with graphite, characterized by a transmittance value between 0.148 W/m2K and 0.153 W/m2K. The other two configurations, characterized by the use of natural materials, showed worse performance with conductance values about 20% higher than EPS. The percentage differences between the two heat flux sensors for the experimental campaigns ranged from 2.8% to 4.4%.

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Thermal performance evaluation of traditional walls and roof used in tropical climate using guarded hot box

Cited by 34 publications

References 17 publications

Construction and Calibration of a Unique Hot Box Apparatus

Construction and Calibration of a Unique Hot Box Apparatus

The Changes in Thermal Transmittance of Window Insulating Glass Units Depending on Outdoor Temperatures in Cold Climate Countries

Experimental analysis of insulating materials using Guarded Hot Box - Preliminary results

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