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Nowadays, given the high cost of an experimental phase and to validate the developed models, the calculator is used by more and more researchers. However, experimentation is a major step to validate any model. To get some accurate data, the devices must be efficient. That is why their prices is very expensive. To overcome this problem, researchers leading to new approaches for developing their own prototypes. The challenge is to have accuracy devices for a lower cost. Measurement of diffuse illuminance requires the use of a device to mask the solar disk, like the shadow-ring. In this paper, a manufacturing protocol is proposed to design a shadow-ring, named SHADECO, according to the latitude of the study site and composed of basic materials. For the same efficiency, it allows a cost 4 to 6 times lower than industrial ring. To demonstrate the low cost-saving ratio of the data obtains, a study was conducted on predictive modeling of the behavior of an indoor lighting device. Two models are compared: one using diffuse illuminance deduced (from k t ) and the other using the diffuse illuminance obtained with SHADECO. Using data measured instead of data deduced can improve by almost 34% the model's accuracy. [ABSTRACT FROM AUTHOR]

The use of phase change materials (PCMs) as a building integrated thermal storage may contribute to improving building energy performances. This article focuses on the integration of PCMs in the roof with a non-ventilated air layer, in order to assess thermal performances of a dedicated test cell, especially for thermal comfort. An experimental equipment was set up at Reunion Island under tropical and humid climatic conditions. A mathematical model, based on the apparent heat capacity method is used to predict the actual impact of PCMs on energy consumption as well as thermal comfort. Once the comparisons are performed with simulations, the use of the psychrometric chart, Predicted Mean Vote and Predicted Percentage of Dissatisfied indexes, shows that in the tested configurations, thermal comfort can be improved. Indeed, as well as to enhance the thermal energy storage, the given configuration also reduce the solar radiation through the roof, due to the reflective properties of PCMs panel surfaces. A positive effect on inside air temperature of the full-scale experimental test cell is particularly observed. [ABSTRACT FROM AUTHOR]

In a concerning global energy context, the construction industry must be able to respond both in terms of energy management and the comfort of its buildings’ occupants. In this context, innovative devices using daylighting can provide an obvious answer. The Tubular Devices Guide Systems (TDGS) are innovative daylighting processes based on light transport. They offer a real response to the diurnal energy consumption (frequently in tertiary). However, today's design will make tomorrow's building. This is why it is necessary to better adjust our prediction tools to optimize the use of these technologies and their coupling to active processes (artificial lighting). The literature reveals a disparity in performance prediction tools for light pipes. Two causes are targeted: the adjustment of semi-empirical models and their accuracy. This article offers some solutions to both problems. We propose a new form of model (improved accuracy) associated with a generalized modelling protocol (response to the adjustment) through a model generator named HEMERA. Our approach is organized around a Galilean sequence, i.e., we rely on observation and results of an experimental study in real weather conditions to better understand the phenomena and validate the developed model. Energy autonomy and user comfort in the building are at the heart of our concern, and we will provide evidence to validate the use of TDGS in buildings. In this context, we propose an energy equivalence between the light pipe and artificial lighting. [ABSTRACT FROM AUTHOR]

This paper deals with the empirical validation of a building thermal model of a complex roof including a phase change material (PCM). A mathematical model dedicated to PCMs based on the heat apparent capacity method was implemented in a multi-zone building simulation code, the aim being to increase the understanding of the thermal behavior of the whole building with PCM technologies. In order to empirically validate the model, the methodology is based both on numerical and experimental studies. A parametric sensitivity analysis was performed and a set of parameters of the thermal model has been identified for optimization. The use of the generic optimization program called GenOpt® coupled to the building simulation code enabled to determine the set of adequate parameters. We first present the empirical validation methodology and main results of previous work. We then give an overview of GenOpt® and its coupling with the building simulation code. Finally, once the optimization results are obtained, comparisons of the thermal predictions with measurements are found to be acceptable and are presented. [ABSTRACT FROM AUTHOR]

This article deals with a new configuration of a complex roof using a phase change material (PCM) installed on a dedicated test cell. For the first time and in field conditions, an experimental device using phase change material was set up at Reunion Island, location having a tropical and humid climate. Results show that in the tested configurations and for a non-ventilated air layer, the measured temperatures were on either side of the PCM's melting point. It means that the PCM is able to store thermal energy in the daytime and release it at night. Furthermore, this study allowed to determine the thermal resistance of the roof via a mean method meeting international standards (ISO 9869) using dynamic data. The method was implemented in a multi-zone building software, named ISOLAB, in order to automatically determine the thermal indicator. [ABSTRACT FROM AUTHOR]

Highlights: [•] A model phase change materials (PCMs) integrated in a complex roof of building is presented. [•] The first two steps of the validation methodology of numerical model of thermal behavior of phase change materials are highlighted. [•] The model is able to predict thermal behavior of PCM. [•] The thermal impact of PCM on the inside air temperature of building is discussed. [ABSTRACT FROM AUTHOR]

• State of the art on experimental and numerical results on Mirrored Light-Pipe (MLP) • New experimental observations on MLP in high solar potential climates. • Various scenarios studied (impact of the reflection coefficient of the area to be illuminated, presence of an anticyclonic dome, type of sky or the ideal position of a sub-dome deflector). This paper focuses on the part of Tubular Daylight Guide Systems (TDGS): the Mirrored Light-Pipe (MLP). MLP is part of the multiple specular reflection conveyors. They allow daylight to be transported and distributed in dark rooms far from traditional openings while limiting heat transmission. It involves collecting, concentrating, and diffusing sunlight using a dome placed on the roof. It is then conveyed through a highly reflective tube and diffused into a building's room using a diffuser. Previous work (Malet-Damour et al., 2017, 2016) has shown that it was necessary to identify and study the climate in which the light pipe will be installed. A state-of-the-art of experimental and numerical results was conducted over the period from1990 to 2019. It revealed that the behavior of the light pipe depends strongly on the indoor (area to be illuminated) and outdoor (meteorology) environment. This paper presents the experimental observations of studies conducted from 2013 to 2015 on Mirrored Light-Pipe in Reunion Island. The climate in which the experiment was undertaken is presented with a focus on illuminance. In 2019, this study is the only one analyzing the performance of the light pipe in extreme situations of extreme sunlight conditions (maximum global illuminance of around 200 Klux). Experimental results based on various scenarios quantified the impact of the reflection coefficient of the area to be illuminated, the presence of an anticyclonic dome, the type of sky or the ideal position of a sub-dome deflector. The results are very encouraging. [ABSTRACT FROM AUTHOR]

Abstract: This paper deals with the experimental evaluation of a roof-mounted multi-reflective radiant barrier (MRRB), installed according to the state of the art, on a dedicated test cell. An existing experimental device was completed with a specific system for the regulation of the airflow rate in the upper air layer included in a typical roof from Reunion Island. Several experimental sequences were conducted to determine the thermal resistance of the roof according to several parameters and following a specific method. The mean method, well known in international standards (ISO 9869-1994) for the determination of the thermal resistance using dynamic data, was used. The method was implemented in a building simulation code in order to allow the determination of the thermal indicator automatically. Experimental results are proposed according to different seasonal periods and for different values of the airflow rate in the upper air layer. [Copyright &y& Elsevier]

Abstract: This article deals with the optimization and validation of a thermal model of photovoltaic panels integrated to buildings. The PV thermal model is implemented in the building simulation code ISOLAB and have already been the subject of previous works. The optimization is made by using the generic optimization program GenOpt. First, these two programs are presented. Secondly, the case study is presented both experimental and modeling way, and main results of previous work are given. Thirdly, the validation methodology is described. Fourthly, the coupling between ISOLAB and GenOpt is presented, and optimization and validation criteria are given. Finally, results of the experimental optimization are presented and the model is validated. [Copyright &y& Elsevier]