scholarly journals Optimization of a Combination of Thermal Insulation and Cool Roof for the Refurbishment of Social Housing in Southern Spain

2021 ◽  
Vol 13 (19) ◽  
pp. 10738
Author(s):  
Carlos-Antonio Domínguez-Torres ◽  
Helena Domínguez-Torres ◽  
Antonio Domínguez-Delgado

Social housing built in the middle of the last century in Spain suffers from poor thermal insulation conditions that cause situations of discomfort and energy poverty. For this reason, the energetic refurbishment of the envelope of this social building stock is necessary to overcome these situations and reduce energy consumption aimed at achieving interior comfort for its occupants. The goal of this work is to optimize a constructive solution that combines cool roof techniques with the use of thermal insulation applied to the refurbishment of the roof of buildings belonging to a quarter of social housing in Seville, Spain. The optimization analysis is based on the computation of the energy performance of the roofs when the energy retrofitting measure is applied, considering a variety of combinations of solar reflective coatings and insulation layer thickness, performing a dynamic analysis that accounts for the aging effect of the cool coats on the monthly roof energy performance and on the economic balance for the whole life cycle (LC) span. Economic and energy optimization analysis show that a suitable combination of cool roof emissivity and insulation layer thickness produces significant savings in the operational energy and in the economic profitability of the proposed retrofitting measure: the optimum combination obtained provides for the entire life cycle timespan an energy savings of 5.71 GJ/m2 and a cost savings equivalent to the 63.1% of the total costs when compared to the non-refurbished roof. The application of a time-dependent pattern for the changes on time produced by the aging effect on the cool roof emissivity, and its effects on the optimization of the combination of cool roof and insulation layer, can be considered novel in literature, both from an energy and an economic point of view.

2020 ◽  
Vol 12 (14) ◽  
pp. 5602
Author(s):  
Antonio Dominguez-Delgado ◽  
Helena Domínguez-Torres ◽  
Carlos-Antonio Domínguez-Torres

Energy refurbishment of the housing stock is needed in order to reduce energy consumption and meet global climate goals. This is even more necessary for social housing built in Spain in the middle of the last century since its obsolete energy conditions lead to situations of indoor thermal discomfort and energy poverty. The present study carries out a life cycle assessment of the energy and economic performance of roofs after being retrofitted to become cool roofs for the promotion of social housing in Seville (Spain). Dynamic simulations are made in which the time dependent aging effect on the energy performance of the refurbished cool roofs is included for the whole lifespan. The influence of the time dependent aging effect on the results of the life cycle economic analysis is also assessed. A variety of scenarios are considered in order to account for the aging effect in the energy performance of the retrofitted cool roofs and its incidence while considering different energy prices and monetary discount rates on the life cycle assessment. This is made through a dynamic life cycle assessment in order to capture the impact of the aging dynamic behavior correctly. Results point out significant savings in the operational energy. However, important differences are found in the economic savings when the life cycle analysis is carried out since the source of energy and the efficiency of the equipment used for conditioning strongly impact the economic results.


2019 ◽  
Vol 11 (16) ◽  
pp. 4487 ◽  
Author(s):  
Sattler ◽  
Österreicher

Building refurbishment plays a key role in the de-carbonization of the European building stock. Whilst the renewal of the thermal envelope increases energy efficiency during the operational phase, the type of material is highly relevant for the overall environmental impact of the refurbishment. Expanded polystyrene (EPS) is most widely used for external thermal insulation systems but is also a material based on fossil resources. Thus, alternatives made from renewable raw materials must be more widely used in order to reach the climate goals. However, comparable data on long-term material effects over the life cycle are needed for developers and planners to make informed decisions. In a Viennese case study for the largest social housing property manager in Europe, two different façade systems have been analyzed to assess the overall environmental impact of the materials. In a comprehensive life cycle assessment, a Multi-Active Façade system based on recycled paper has been compared with a conventional external thermal insulation composite system (ETICS) using EPS. It shows that whilst the evaluation during the operational phase alone results in a similar ecological footprint of the ETICS, the analysis over the whole life cycle provides a clear positive indication for the novel Multi-Active Façade.


Energies ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 3354 ◽  
Author(s):  
Piselli ◽  
Pisello ◽  
Saffari ◽  
Gracia ◽  
Cotana ◽  
...  

Cool roof effectiveness in improving building thermal-energy performance is affected by different variables. In particular, roof insulation level and climate conditions are key parameters influencing cool roofs benefits and whole building energy performance. This work aims at assessing the role of cool roof in the optimum roof configuration, i.e., combination of solar reflectance capability and thermal insulation level, in terms of building energy performance in different climate conditions worldwide. To this aim, coupled dynamic thermal-energy simulation and optimization analysis is carried out. In detail, multi-dimensional optimization of combined building roof thermal insulation and solar reflectance is developed to minimize building annual energy consumption for heating–cooling. Results highlight how a high reflectance roof minimizes annual energy need for a small standard office building in the majority of considered climates. Moreover, building energy performance is more sensitive to roof solar reflectance than thermal insulation level, except for the coldest conditions. Therefore, for the selected building, the optimum roof typology presents high solar reflectance capability (0.8) and no/low insulation level (0.00–0.03 m), except for extremely hot or cold climate zones. Accordingly, this research shows how the classic approach of super-insulated buildings should be reframed for the office case toward truly environmentally friendly buildings.


2019 ◽  
Vol 111 ◽  
pp. 03065
Author(s):  
Yiğit Yılmaz ◽  
Burcu Çiğdem Yılmaz

The importance of building energy performance has been substantially increasing in the last decades due to the global warming. Therefore, buildings within the existing stock and the new buildings are encouraged to achieve the energy performance restrictions and efficiency levels. In this context, a social housing archetype (Harct), which is constructed in each climate region of Turkey with a common design approach for temperate climate region, is evaluated as a base case to improve the energy performance for the cold climate region by the optimization of the life cycle cost (LCC). It is, namely, aimed to not only improve the energy performance of the archetype but also to ensure optimal cost efficiency as significant criterion. It is focused to optimize the façades of the Harct in terms of window width, and optic and thermo-physical properties of the façade with determining the efficient insulation thickness level for exterior walls and efficient glazing types for windows. Firstly, façade design is analysed to find out the minimum and maximum windows’ widths to achieve the optimal window sizes. Secondly, optic and thermo-physical properties and cost data of the opaque and transparent façade elements have been designated among the market products in accordance with the current regulations. Energy model of the building has been run by Energy Plus simulation tool, in order to integrate it with GenOpt for optimization. Optimization was performed to carry out efficient frontier cases. The results were evaluated from life cycle cost (LCC) and energy efficiency point of view to highlight the cost optimal point


2011 ◽  
Vol 90-93 ◽  
pp. 3057-3060 ◽  
Author(s):  
Jian Jun Liu ◽  
Gui Hong Pei ◽  
You Jun Ji

Steam stimulation is one of the main methods used in heavy oil reservoir development. How to inject high temperature and high dryness steam is a key factor to enhance heavy oil recovery. It is significant to evaluate heat transfer of steam pipeline and optimize thermal insulation layer for heavy oil exploitation. Based on fluid mechanics, heat transfer theory, considered phase change, mathematical model to calculate heat transfer and heat loss of steam pipeline was derived. Using COMSOL Multiphysics, a finite element based program for simulating unlimited multiphysics and single physics applications, the author simulated heat transferring in ground steam pipeline and analyzed the effect of thermal insulation layer. From the simulation results, it was known that, (1) Along with the pipeline distance increases, the steam dryness decreases, the decrease rate decreases with the distance increases. (2) At the same transmission distance, the bigger the thermal insulation layer thickness is, the smaller the heat loss of the steam is. The heat loss of steam transmission mainly center on the first half pipeline. (3) With the thickness of thermal insulation layer increases, the heatloss declines. After the thickness of thermal insulation layer increases 90 mm, increasing the thickness has no obvious effect on reducing the heat loss. So, it is suggested that the thermal insulation layer thickness should be 75-80mm.


2019 ◽  
Vol 9 (7) ◽  
pp. 1285 ◽  
Author(s):  
José D. Silvestre ◽  
André M. P. Castelo ◽  
José J. B. C. Silva ◽  
Jorge M. C. L. de Brito ◽  
Manuel D. Pinheiro

This paper analyses the environmental, energy, and economic performances of the External Thermal Insulation Composite System (ETICS) using agglomerated insulation cork board (ICB) or expanded polystyrene (EPS) as insulation material applied in the energetic renovation of the building envelope during a 50-year study period. A comparison between ETICS using ICB and EPS, for the same time horizon, is also presented. The environmental balance is based on “Cradle to Cradle” (C2C) Life Cycle Assessment (LCA), focusing on the carbon footprint and consumption of nonrenewable primary energy (PE-NRe). The characteristics of these products in terms of thermal insulation, the increased energy performance provided by their installation for retrofit of the buildings’ envelope, and the resulting energy savings are considered in the energy balance. The estimation of the C2C carbon and PE-NRe saved is considered in the final balance between the energy and environmental performances. ETICS with ICB is environmentally advantageous both in terms of carbon footprint and of PE-NRe. In fact, the production stage of ICB is less polluting, while EPS requires lower energy consumption to fulfil the heating and cooling needs of a flat, due to its lower U-Value, and its lower acquisition cost results in a lower C2C cost. Comparing both ETICS’ alternatives with reference solutions, it was found that the latter only perform better in the economic dimension, and only for an energy consumption to fulfil less than 25% of the heating and cooling needs. This paper represents an advance to the current state-of-the-art by including all the life-cycle stages and dimensions of the LCA in the analysis of solutions for energy renovation of building envelopes.


2017 ◽  
Vol 898 ◽  
pp. 1970-1977
Author(s):  
Yao Li ◽  
Xian Zheng Gong ◽  
Qing Hua Zhang ◽  
Chong Qi Shi

External wall thermal insulation system protects the major structure of building effectively. In this study, a student dormitory building with typical external wall thermal insulation system in Beijing was chosen as the research object and the energy consumption analysis was conducted to identify the optimal external thermal insulation system during the whole life cycle. The results show: for brick-concrete buildings, the consumption of clay brick, reinforced concrete and cement mortar account for more than 95% of the total materials consumption, where reinforced concrete contributes most to energy consumption. The external insulation system with similar heat transfer coefficient but consist of different insulation materials mainly affects energy consumption in materials production phase (the difference of building production energy consumption is about 7.2%), while has no significant effect in building operation phase and whole life cycle. With the increase of heat transfer coefficient, the energy consumption decreases in materials production phase, accounting for 16.3%-21.9% of the life cycle energy consumption, increases in building operation phase, accounting for 78.1%-83.7%, and can be neglected in the disposal phase. And there exists an optimization value in building whole life cycle, at which the minimum value of the energy consumption reaches, when the heat transfer coefficient is 0.3W / (m2 • K), equivalent to 127mm EPS insulation thickness or 151mm rock wool insulation thickness.


Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6680
Author(s):  
Tatjana Vilutienė ◽  
Rasa Džiugaitė-Tumėnienė ◽  
Diana Kalibatienė ◽  
Darius Kalibatas

This paper presents a systematic mapping (SM) study with the aim to determine how Building Information Modeling (BIM) methodologies and technologies contribute to energy-related analyses over the course of the entire building life cycle. The method adopted in the study is based on a set of seven research questions. We used a mixed technique combining co-citation analysis and bibliographic coupling in order to analyze the publications’ datasets for the period 2010–2020. The main advantage and novelty of this study are that the joint dataset from the Scopus and Web of Science databases was used to develop the keyword map. The main findings of this study indicate that many BIM-based applications can be used to analyze the building energy performance at all stages of the building life cycle. However, the applications of BIM in conjunction with other information technologies are limited and are still in the initial stage. In the future, the main improvements should be focused on process, model, system, tool, use and information modeling. The most promising long-term solution is an open BIM framework based on open standards, which allows the integration of BIM and energy simulation tools and satisfies specific data exchange requirements.


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