Adaptive opaque façades and their potential to reduce thermal energy use in residential buildings: A simulation-based evaluation

2021 ◽  
pp. 174425912110454
Author(s):  
Miren Juaristi ◽  
Fabio Favoino ◽  
Tomás Gómez-Acebo ◽  
Aurora Monge-Barrio

Adaptive façades are a promising choice to achieve comfortable low-energy buildings. Their effective performance is highly dependent on the local boundary conditions of each application and on the way the dynamic properties are controlled. The evaluation of whole building performance through building performance simulation can be useful to understand the potential of different Adaptive opaque façades (AOF) in a specific context. This paper evaluates through dynamic simulations promising design solutions of AOF for a residential building use in six different climates. It quantifies the total delivered thermal energy of 15 typologies of AOFs which consist of alternative adaptation strategies: (i) variation of solar absorptance of the cladding, (ii) variation of the convective heat transfer of air cavities and (iii) adaptive insulation strategies. For the first time, it also quantifies the performance of AOF which combine more than one adaptation strategy. The results show that the variation of the heat transfer by means of Adaptive Insulation components has the most significant impact on the reduction of the thermal energy use. The variation of the solar absorptance has also a significant positive impact when reducing heating consumption, but only if this adaptation strategy is actively controlled and combined with Adaptive Insulation components.

2019 ◽  
Vol 43 (3) ◽  
pp. 229-249 ◽  
Author(s):  
Shahrzad Soudian ◽  
Umberto Berardi

This article investigates the possibility to enhance the use of latent heat thermal energy storage (LHTES) as an energy retrofit measure by night ventilation strategies. For this scope, phase change materials (PCMs) are integrated into wall and ceiling surfaces of high-rise residential buildings with highly glazed facades that experience high indoor diurnal temperatures. In particular, this article investigates the effect of night ventilation on the performance of the PCMs, namely, the daily discharge of the thermal energy stored by PCMs. Following previous experimental tests that have shown the efficacy of LHTES in temperate climates, a system comprising two PCM layers with melting temperatures selected for a year-around LHTES was considered. To quantify the effectiveness of different night ventilation strategies to enhance the potential of this composite PCM system, simulations in EnergyPlusTM were performed. The ventilation flow rate, set point temperature, and operation period were the main tested parameters. The performance of the PCMs in relation to the variables was evaluated based on indoor operative temperature and cooling energy use variations in Toronto and New York in the summer. The solidification of the PCMs was analyzed based on the amount of night ventilation needed in each climate condition. The results quantify the positive impact of combining PCMs with night ventilation on cooling energy reductions and operative temperature regulation of the following days. In particular, the results indicate higher benefits obtainable with PCMs coupled with night ventilation in the context of Toronto, since this city experiences higher daily temperature fluctuations. The impact of night ventilation design variables on the solidification rate of the PCMs varied based on each parameter leading to different compromises based on the PCM and climate characteristics.


2019 ◽  
Vol 38 (1) ◽  
pp. 176-191 ◽  
Author(s):  
Kay Rogage ◽  
Adrian Clear ◽  
Zaid Alwan ◽  
Tom Lawrence ◽  
Graham Kelly

Purpose Buildings and their use is a complex process from design to occupation. Buildings produce huge volumes of data such as building information modelling (BIM), sensor (e.g. from building management systems), occupant and building maintenance data. These data can be spread across multiple disconnected systems in numerous formats, making their combined analysis difficult. The purpose of this paper is to bring these sources of data together, to provide a more complete account of a building and, consequently, a more comprehensive basis for understanding and managing its performance. Design/methodology/approach Building data from a sample of newly constructed housing units were analysed, several properties were identified for the study and sensors deployed. A sensor agnostic platform for visualising real-time building performance data was developed. Findings Data sources from both sensor data and qualitative questionnaire were analysed and a matrix of elements affecting building performance in areas such as energy use, comfort use, integration with technology was presented. In addition, a prototype sensor visualisation platform was designed to connect in-use performance data to BIM. Originality/value This work presents initial findings from a post occupancy evaluation utilising sensor data. The work attempts to address the issues of BIM in-use scenarios for housing sector. A prototype was developed which can be fully developed and replicated to wider housing projects. The findings can better address how indoor thermal comfort parameters can be used to improve housing stock and even address elements such as machine learning for better buildings.


2021 ◽  
Vol 945 (1) ◽  
pp. 012067
Author(s):  
Syed Ahmad Farhan ◽  
Nasir Shafiq ◽  
Nadzhratul Husna ◽  
Azni Zain-Ahmed ◽  
Mohamed Mubarak Abdul Wahab ◽  
...  

Abstract Residential roof assemblies in tropical countries, such as Malaysia, are exposed to intense solar radiation throughout the day all-year round due to the high altitude of the sun path as well as the horizontal orientation and high position of the roof in relation to other components of the building envelope. Residential buildings typically employ a lightweight pitched roof with roof tiles and an attic space above a ceiling board. Diurnal heat transfer into the building through the roof assembly can be minimized by reflecting heat at the roof surface via the application of white paint on high-albedo roof tiles as well as resisting heat via installation of bulk rafter insulation within the roof assembly. However, their adoption will have an influence on the nocturnal heat transfer and, accordingly, the resultant thermal-energy performance. Hence, thermal-energy performances of high-albedo roof tiles and bulk rafter insulation were compared to develop an energy-efficient pitched residential roof assembly that is capable of minimizing diurnal heat transfer into the building with less obstruction of the nocturnal heat transfer in the opposite direction. Evaluation of thermal-energy performance was performed on a Building Information Model, which either adopts, solely, the application of white paint on high-albedo roof tiles, or, in amalgamation with, the installation of bulk rafter insulation within the roof assembly. The simulation projected that the application of white paint on high-albedo roof tiles can generate annual energy savings of 13.14 % and, when adopted in amalgamation with the installation of bulk rafter insulation within the roof assembly, 13.91 %.


1998 ◽  
Vol 26 (1) ◽  
pp. 51-62
Author(s):  
A. L. A. Costa ◽  
M. Natalini ◽  
M. F. Inglese ◽  
O. A. M. Xavier

Abstract Because the structural integrity of brake systems and tires can be related to the temperature, this work proposes a transient heat transfer finite element analysis (FEA) model to study the overheating in drum brake systems used in trucks and urban buses. To understand the mechanics of overheating, some constructive variants have been modeled regarding the assemblage: brake, rims, and tires. The model simultaneously studies the thermal energy generated by brakes and tires and how the heat is transferred and dissipated by conduction, convection, and radiation. The simulated FEA data and the experimental temperature profiles measured with thermocouples have been compared giving good correlation.


Author(s):  
Peter Rez

Most of the energy used by buildings goes into heating and cooling. For small buildings, such as houses, heat transfer by conduction through the sides is as much as, if not greater than, the heat transfer from air exchanges with the outside. For large buildings, such as offices and factories, the greater volume-to-surface ratio means that air exchanges are more significant. Lights, people and equipment can make significant contributions. Since the energy used depends on the difference in temperature between the inside and the outside, local climate is the most important factor that determines energy use. If heating is required, it is usually more efficient to use a heat pump than to directly burn a fossil fuel. Using diffuse daylight is always more energy efficient than lighting up a room with artificial lights, although this will set a limit on the size of buildings.


2021 ◽  
Vol 13 (5) ◽  
pp. 2590
Author(s):  
S. A. M. Mehryan ◽  
Kaamran Raahemifar ◽  
Leila Sasani Gargari ◽  
Ahmad Hajjar ◽  
Mohamad El Kadri ◽  
...  

A Nano-Encapsulated Phase-Change Material (NEPCM) suspension is made of nanoparticles containing a Phase Change Material in their core and dispersed in a fluid. These particles can contribute to thermal energy storage and heat transfer by their latent heat of phase change as moving with the host fluid. Thus, such novel nanoliquids are promising for applications in waste heat recovery and thermal energy storage systems. In the present research, the mixed convection of NEPCM suspensions was addressed in a wavy wall cavity containing a rotating solid cylinder. As the nanoparticles move with the liquid, they undergo a phase change and transfer the latent heat. The phase change of nanoparticles was considered as temperature-dependent heat capacity. The governing equations of mass, momentum, and energy conservation were presented as partial differential equations. Then, the governing equations were converted to a non-dimensional form to generalize the solution, and solved by the finite element method. The influence of control parameters such as volume concentration of nanoparticles, fusion temperature of nanoparticles, Stefan number, wall undulations number, and as well as the cylinder size, angular rotation, and thermal conductivities was addressed on the heat transfer in the enclosure. The wall undulation number induces a remarkable change in the Nusselt number. There are optimum fusion temperatures for nanoparticles, which could maximize the heat transfer rate. The increase of the latent heat of nanoparticles (a decline of Stefan number) boosts the heat transfer advantage of employing the phase change particles.


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