A method for the experimental evaluation in situ of the wall conductance

Cucumo, Mario Antonio; Rosa, A De; Ferraro, Vittorio; Kaliakatsos, Dimitrios; Marinelli, V.

doi:10.1016/j.enbuild.2005.06.005

Cited by 39 publications

(23 citation statements)

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“…The fundamental difference between Equations (1) and (5) is in the numerator of the equations: in Equation (1) it is necessary to measure the heat flux of the wall, so the result is subject to a possible disruption of the heat flux due to the use of the plate [32][33][34] and has a high level of uncertainty associated with its location [35][36][37], while in Equation (5) the necessary variable measurement is only carried out by temperature probes, reducing the error associated with the probes' location.…”

Section: Theorymentioning

confidence: 99%

“…Peng and Wu [35] demonstrated that the main contribution to error in the thermal transmittance results is due to the heat flux measurement. Cucumo et al [36] indicated that the location of the plate has an influence on the correct heat flux measurement. In this sense, Meng et al [37] established that the maximum error of the U-value due to the use of thermocouples can be up to 6%, while that caused by the use of a heat flux plate can reach up to 26%.…”

Section: Introductionmentioning

confidence: 99%

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Determining the U-Value of Façades Using the Thermometric Method: Potentials and Limitations

et al. 2018

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Abstract:The thermal transmittance of building envelopes determines to a large extent the energy demand of buildings. Thus, there is a keen interest in having methods which can precisely evaluate thermal transmittance. From a scientific point of view, this study analyses the viability of the application of the thermometric method (THM), one of the most used methods in Spain. For this purpose, the test method has been improved by determining the adequate test conditions, the selection and installation of equipment, data acquisition and post-processing, and the estimation of uncertainty. We analyse eight case studies in a Mediterranean climate (Csa) to determine the potentials and limitations of the method. The results show that the values obtained through THM are valid under winter environmental conditions with relative uncertainties between 6% and 13%, while difficulties to perform the test in optimal conditions, and therefore to obtain valid results in warmer seasons, are detected. In this regard, the case studies which obtained a greater number of observations by performing the filtrate conditions were able to obtain representative results. Furthermore, there are significant differences depending on the kind of equipment and probes used during the experimental campaign. Finally, in warm climate regions a data filtrate can be considered for observations of a temperature difference higher than 5 • C, obtaining valid results for the case studies, although the rise in the thermal gradient can guarantee a greater stability of data.

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Section: Theorymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Determining the U-Value of Façades Using the Thermometric Method: Potentials and Limitations

et al. 2018

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“…Reference [11] suggested a method to estimate the thermal parameters of building envelopes, especially the thermal capacitance of insulation materials of a wall by using a heat flow meter in laboratory. Reference [12] also estimated the thermal equivalent conductance and the thermal equivalent capacitance of a testing wall of a constructed building by conducting on experiments in situ. The parameters were obtained by treating the measured heat flux and the measured wall temperature.…”

Section: State-of-the-art Literaturementioning

confidence: 99%

“…The parameters are obtained by experimental data and numerical calculations [10][11][12][13][14]. Reference [11] suggested a method to estimate the thermal parameters of building envelopes, especially the thermal capacitance of insulation materials of a wall by using a heat flow meter in laboratory.…”

Section: State-of-the-art Literaturementioning

confidence: 99%

Modeling of a Building System and its Parameter Identification

Park¹,

Martaj²,

Ruellan³

et al. 2013

Journal of Electrical Engineering and Technology

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-This study proposes a low order dynamic model of a building system in order to predict thermal behavior within a building and its energy consumption. The building system includes a thermally well-insulated room and an electric heater. It is modeled by a second order lumped RC thermal network based on the thermal-electrical analogy. In order to identify unknown parameters of the model, an experimental procedure is firstly detailed. Then, the different linear parametric models (ARMA, ARX, ARMAX, BJ, and OE models) are recalled. The parameters of the parametric models are obtained by the least square approach. The obtained parameters are interpreted to the parameters of the physically based model in accordance with their relationship. Afterwards, the obtained models are implemented in Matlab/Simulink® and are evaluated by the mean of the sum of absolute error (MAE) and the mean of the sum of square error (MSE) with the variable of indoor temperature of the room. Quantities of electrical energy and converted thermal energy are also compared. This study will permit a further study on Model Predictive Control adapting to the proposed model in order to reduce energy consumption of the building.

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“…Reported experimental results show a difference with U-values determined by the HFM of the order of 30-35%. For a quite long time several other methods that do not involve infrared thermography have been in use for experimental determination of thermal transmittance of the building elements, like hot box method [8,9] or the temperature based method [10]. The hot box method is mainly used for thermal transmittance measurements of inhomogeneous components such as windows, doors and thermal bridges in laboratory and cannot be used for in situ measurements.…”

Section: Introductionmentioning

confidence: 99%