Experimental determination of time lag and decrement factor

Toure, Pape Moussa; Dieye, Younouss; Gueye, Prince Momar; Sabourin, Vincent; Bodian, Séckou; Tiguampo, Sumailla

doi:10.1016/j.cscm.2019.e00298

Cited by 11 publications

(8 citation statements)

References 18 publications

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“…Thermal comfort can be attained with building materials of high time lag and low decrement factor. Thus, these dynamic thermal characteristics have been studied, specifically for lightweight concrete [11][12][13][14], earth bricks [15], thermal insulation concrete [16], reinforced mortar channels [17], building element of the wall [18], etc. The voids within the concrete are able to resist the thermal transfer from outdoor to indoor.…”

Section: Introductionmentioning

confidence: 99%

Thermal Performance of Structural Lightweight Concrete Composites for Potential Energy Saving

et al. 2021

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Residential consumption dominates the energy expenditure of heating and cooling systems, especially in tropical climates where building envelopes play an important role in energy efficiency. The thermal properties of concrete that are commonly employed as the building envelope material affect directly human comfort in a building. In addressing both the concrete thermal performance and industrial waste issues, this paper experimentally studies the concrete compressive strength and thermal properties used later for comparative energy analysis for human comfort. Four design mixes and a conventional concrete as control specimen are considered utilizing industrial wastes; palm oil fly ash (POFA), lightweight expanded clay aggregate (LECA), oil palm shell (OPS), and quarry dust, as constituents. These mixes are cast for cube compressive strength (to ensure the achievement of structural concrete requirement) and small-scaled wall tests. The measurement of surface temperatures of scaled wall tests is conducted in a polystyrene box to determine the concrete time lag and decrement factor. It is found that the density of concrete governs the compressive strength and that air pockets in the concrete matrix play an essential role as far as the thermal properties are concerned. From the energy analysis, structural lightweight concrete may save approximately 50% of the residential energy consumption.

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Section: Introductionmentioning

confidence: 99%

Thermal Performance of Structural Lightweight Concrete Composites for Potential Energy Saving

et al. 2021

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“…, respectively of 0.61 and 4.50 h are low for adequate thermal inertia when compared to values of 6 hours of time lag and 0.40 of decrement factor for sufficient thermal inertia[44]. Toure et al[43] found time lag values in the range 6.02 h -6.38 h and decrement factor in the range 0.38-0.43 by experimental analysis for a 1x1x1 m 3 test cell of 14 cm stabilised earth blocks with cement. The discrepancies with the present results may be mainly due to the test cell scale, difference in CEB thermophysical properties and air humidity that can impact the thermal properties.…”

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confidence: 94%

Impact of insulation and wall thickness in compressed earth buildings in hot and dry tropical regions

Neya

Yamegueu

Coulibaly

et al. 2021

Journal of Building Engineering

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“…Childs [8], in analysing the effect of the thermal capacity of a building in which no heating or cooling is expected to be used, states that such an effect can then be limited to changes in the magnitude of the diurnal variation of internal temperature and its distribution over a 24 h period. Similarly, the thermal inertia of a building is related to its thermal performance by most other authors, who tend to consider three parameters as the most relevant: the decrement factor, the time lag [25][26][27][28], and the reduction of peak temperatures at the hottest times of the day [29][30][31]. While the decrement factor is understood as the degree by which the diurnal variation of the indoor temperature decreases with respect to the outdoor temperature, the time lag describes how much the occurrence of the maximum indoor temperature is delayed with respect to the outdoor temperature.…”

Section: Introduction 1state Of the Artmentioning

confidence: 99%

Cumulative Multi-Day Effect of Ambient Temperature on Thermal Behaviour of Buildings with Different Thermal Masses

Staszczuk,

Kuczyński

2023

Energies

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In most studies, the effect of the thermal capacity of the building envelope on changes in internal temperatures is reduced to a 24 h period. During this period, daytime heat gains are balanced by nighttime heat losses. The maximum indoor temperature, the diurnal variation of the indoor temperature and the time lag between the occurrence of the maximum daily temperature determine the effect achieved. The aim of the article was to show that the effect of the thermal capacity of a building on the indoor temperature is not limited to 24 h but accumulates over a period of several days, mainly depending on the temperature and solar radiation history of the previous days. As a result, contrary to what some studies have suggested, the bedrooms of heavier buildings remained significantly colder at night during periods of prolonged high outdoor temperatures. The results obtained may fundamentally influence the perception of the effect of using the high thermal capacity of the building envelope to reduce high indoor temperatures in hot weather.

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Experimental determination of time lag and decrement factor

Cited by 11 publications

References 18 publications

Thermal Performance of Structural Lightweight Concrete Composites for Potential Energy Saving

Thermal Performance of Structural Lightweight Concrete Composites for Potential Energy Saving

Impact of insulation and wall thickness in compressed earth buildings in hot and dry tropical regions

Cumulative Multi-Day Effect of Ambient Temperature on Thermal Behaviour of Buildings with Different Thermal Masses

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