scholarly journals Thermal behaviour of green façades in summer

2018 ◽  
Vol 49 (3) ◽  
pp. 183-190 ◽  
Author(s):  
Ileana Blanco ◽  
Evelia Schettini ◽  
Giacomo Scarascia Mugnozza ◽  
Giuliano Vox

Building greenery systems can represent a sustainable solution for new buildings design and for existing buildings retrofitting, in order to improve the thermal energy performance of buildings, to decrease building energy loads and to contrast the Urban Heat Island. Green façades can influence thermal properties of a building by means of different important mechanisms: the shading, the cooling, the insulating and the wind barrier effect. Moreover, green façades accomplish heating effect in the cold season and at nighttime. An experimental test was developed at small scale at the University of Bari (Italy) from 2014 to 2016 for testing two different green façades. The plant species chosen were Pandorea jasminoides variegated and Rhyncospermum jasminoides, two evergreen climbing plants. A third uncovered wall was used as control. The thermal behaviour of the plants was analysed during the 2016 summer season, by keeping in consideration the external surface temperature of the building and the temperature of the airgap behind the green vertical systems. The daylight temperatures observed on the plant-covered walls during representative days were lower than the respective temperatures of the uncovered wall up to 7.0°C. During nighttime, the temperatures behind the plants were higher than the respective temperatures of the control wall up to 2.2°C. The results shown in the present research allow delineating the behaviour of the two plant species during summer in the Mediterranean climate region.

2021 ◽  
Vol 9 (1) ◽  
pp. 34
Author(s):  
Samten Lhendup

The climate is changing very fast today, and this is not natural. We are experiencing the impact of climate change in many aspects. It is also expected to impact the performance of buildings badly in due course of time. In recent years, many countries started investing to evaluate the energy performances of the buildings and opting for the best suited energy-saving measures. However, this concept may be new in the context of Bhutan. However, the author expects that this new concept may revolutionize the building construction sectors in Bhutan. Many studies show that buildings are one of the world’s largest consumers of energy, and on the other hand, strategies are available to reduce energy consumption. The strategies can be applied right from the design phases for the new buildings and retrofits for the old buildings. In order to apply the best strategies of energy consumption reduction and to understand building energy consumption patterns, an evaluation of the building’s energy performance needs to be carried out.


2020 ◽  
Vol 10 (5) ◽  
pp. 1854 ◽  
Author(s):  
Enghok Leang ◽  
Pierre Tittelein ◽  
Laurent Zalewski ◽  
Stéphane Lassue

This article studies a composite solar wall with latent storage (TES) designed to heat rooms inside buildings during the cold season. No numerical model of the composite solar wall is currently available in the Dymola/Modelica software library. The first objective of this work is to develop one such model. The article describes the elementary components, along with the equations that allow modeling the heat transfers and storage phenomena governing both the thermal behavior and performance of the solar wall. This model was built by assembling various existing basic elements from the software’s “Building” library (e.g., models of heat transfer by convection, radiation and conduction) and then creating new elements, such as the storage element incorporating the phase change material (PCM). To validate this solar wall model, numerical results are compared to experimental data stemming from a small-scale composite solar wall manufactured in our laboratory, and the experimental set-up could be tested under real weather conditions. After verifying the level of confidence in the model, the energy performance of two solar walls, one with a conventional storage wall (sensible heat storage) the other containing a PCM (the same as in the experiment), are compared. The result indicates that the solar wall incorporating a PCM does not in this case release any more energy in the room to be heated.


2016 ◽  
Vol 2 (1) ◽  
pp. 49 ◽  
Author(s):  
Miguel Núñez Peiró ◽  
Emilia Román López ◽  
Carmen Sánchez-Guevara Sánchez ◽  
Francisco Javier Neila González

Resumen Esta investigación se enmarca dentro del proyecto MODIFICA (modelo predictivo - Edificios - Isla de Calor Urbano), financiado por el Programa de I + D + i Orientada a los Retos de la sociedad 'Retos Investigación' de 2013. Está dirigido a desarrollar un modelo predictivo de eficiencia energética para viviendas, bajo el efecto de isla de calor urbano (AUS) con el fin de ponerla en práctica en la evaluación de la demanda de energía real y el consumo en las viviendas. A pesar de los grandes avances que se han logrado durante los últimos años en el rendimiento energético de edificios, los archivos de tiempo utilizados en la construcción de simulaciones de energía se derivan generalmente de estaciones meteorológicas situadas en las afueras de la ciudad. Por lo tanto, el efecto de la Isla de Calor Urbano (ICU) no se considera en estos cálculos, lo que implica una importante falta de precisión. Centrado en explorar cómo incluir los fenómenos ICU, el presente trabajo recopila y analiza la dinámica por hora de la temperatura en diferentes lugares dentro de la ciudad de Madrid. Abstract This research is framed within the project MODIFICA (Predictive model - Buildings - Urban Heat Island), funded by Programa de I+D+i orientada a los retos de la sociedad 'Retos Investigación' 2013. It is aimed at developing a predictive model for dwelling energy performance under the Urban Heat Island (UHI) effect in order to implement it in the evaluation of real energy demand and consumption in dwellings. Despite great advances on building energy performance have been achieved during the last years, weather files used in building energy simulations are usually derived from weather stations placed in the outskirts of the city. Hence, Urban Heat Island (UHI) effect is not considered in this calculations, which implies an important lack of accuracy. Focused on exploring how to include the UHI phenomena, the present paper compiles and analyses the hourly dynamics of temperature in different locations within the city of Madrid. 


Climate ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 48
Author(s):  
Pierdonato Romano ◽  
Enrico Prataviera ◽  
Laura Carnieletto ◽  
Jacopo Vivian ◽  
Michele Zinzi ◽  
...  

In recent decades, the cooling energy demand in urban areas is increasing ever faster due to the global warming and the growth of developing economies. In this perspective, the urban building energy modelling community is focusing its research activities on innovative tools and policy actions to improve cities’ sustainability. This work aims to present a novel module of the EUReCA (Energy Urban Resistance Capacitance Approach) platform for evaluating the effects of the interaction between district’s buildings in the cooling season. EUReCA predicts the urban energy demand using a bottom-up approach and low computational resources. The new module allows us to evaluate the mutual shading between buildings and the urban heat island effects, and it is well integrated with the calculation of the energy demand of buildings. The analysis was carried out considering a real case study in Padua (Italy). Results show that the urban heat island causes an average increase of 2.2 °C in the external air temperature mainly caused by the waste heat rejected from cooling systems. This involves an increase in urban cooling energy and electricity demand, which can be affected between 6 and 8%. The latter is the most affected by the urban heat island (UHI), due to the degradation it causes on the HVAC systems’ efficiency.


Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 5208
Author(s):  
Kit Benjamin ◽  
Zhiwen Luo ◽  
Xiaoxue Wang

Urban heat island (UHI) effects significantly impact building energy. Traditional UHI investigation methods are often incapable of providing the high spatial density of observations required to distinguish small-scale temperature differences in the UHI. Crowdsourcing offers a solution. Building cooling/heating load in 2018 has been estimated in London, UK, using crowdsourced data from over 1300 Netatmo personal weather stations. The local climate zone (LCZ) scheme was used to classify the different urban environments of London (UK). Inter-LCZ temperature differences are found to be generally consistent with LCZ temperature definitions. Analysis of cooling degree hours in July shows LCZ 2 (the densest urban LCZ in London) had the highest cooling demand, with a total of 1550 cooling degree hours. The suburban related LCZs 5 and 6 and rural LCZs B and D all had about 80% of the demand of LCZ 2. In December, the rural LCZs A, B and D had the greatest heating demand, with all recording around 5750 heating degree hours. Urban LCZs 2, 5 and 6 had 91%, 86% and 95% of the heating demand of LCZ D, respectively. This study has highlighted both advantages and issues with using crowdsourced data for urban climate and building energy research.


2014 ◽  
Vol 1065-1069 ◽  
pp. 2169-2172 ◽  
Author(s):  
Andrey Benuzh ◽  
Valery Telichenko

With the increasing awareness of sustainable development in the Russian construction industry, implementation of an energy rating procedure to assess buildings is becoming more important. The most representative building environment assessment schemes that are in use today are Building Research Establishment Environmental Assessment Method (BREEAM) and Leadership in Energy and Environmental Design (LEED). This paper aims to focus on the investigation of energy performance assessment for new buildings including the Russian experience within the BREEAM and LEED schemes. A review of the two schemes with regards to their assessment methods, scopes, performance criteria and energy rating scales are presented. Through this study, an attempt is made to make clear how building energy performance is assessed and therefore awarded with energy credits under the international schemes and to form a good basis for future development of a generic energy assessment framework of Russian Federation.


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