Energy and Economic Life Cycle Assessment of Cool Roofs Applied to the Refurbishment of Social Housing in Southern Spain

Self Cite

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.

Section: Methodsmentioning

confidence: 99%

“…Finally, the pattern established in Reference [37] for the time evolution of the solar reflectivity, that collects the foregoing, is used in the computations. This pattern is illustrated in Figures 1 and 2.…”

Section: Changes In Reflectivity Due To Aging Effect and Maintenancementioning

confidence: 99%

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

Domínguez-Torres

Delgado

2021

Self Cite

“…These aspects should be carefully taken into account especially when working on social housing, as their inhabitants are economically, and frequently energy, vulnerable. The article written by Antonio Dominguez-Delgado, Helena Domínguez-Torres and Carlos-Antonio Domínguez-Torres [22] studies not only the energy impact but also the economic one of cool roof constructive solutions through their life cycle in order to evaluate their performance over time as roofs are elements continuously exposed to outdoor climate conditions affecting to the durability of the solution.…”

Section: Background and Contentsmentioning

confidence: 99%

Decarbonization and Circular Economy in the Sustainable Development and Renovation of Buildings and Neighbourhoods

Mercader-Moyano

Esquivias

2020

In recent years, the building sector has been turning towards intervening in the existing city building stock. In fact, it is generally accepted that the refurbishment of buildings and the urban regeneration based on sustainability must form the axis of reformulation of the building sector. Nowadays, achieving sustainable urban development inevitably involves improving existing buildings, thereby preventing the need for city growth, and for the emptying of established neighbourhoods. Furthermore, considering the whole life cycle, it is well known the great amount of greenhouse emissions derived from the construction sector, so in order to reach a decarbonized society it is important to provide eco-efficient construction materials and solutions, adding the principles of circular economy and resource efficiency. The articles of this special issue show different aspects to be considered in order to reach a decarbonized and circular building stock.

“…Moreover, the regions in which the annual heating loads are higher than the cooling loads are located at a high latitude or strongly affected by coastal climate, such as Seoul, Kaesong, Pyongyang, Hamhung, Sinuiju and Chongjin. To reduce the load on buildings, a larger amount of solar radiation should be absorbed in winter, and a high reflectivity should be maintained in summer [25,[74][75][76]. Therefore, this section clarifies the optimum insulation thickness and reflectivity through the total load on a yearly basis.…”

Section: Total Load Resultsmentioning

confidence: 99%

Optimal Combination of External Wall Insulation Thickness and Surface Solar Reflectivity of Non-Residential Buildings in the Korean Peninsula

Kim

2021

To delay fossil energy depletion and implement the Paris Climate Change Accord, the South Korean government is attempting to reduce greenhouse gas emissions with the establishment of the 2030 Roadmap. The insulation performance of external walls is being continuously enhanced in the architectural domain. However, Korea’s policy and construction market focuses only on the heat resistance of buildings’ external walls to enhance the insulation performance, leading to an increased thickness of the insulation materials. In this study, the relationship between the surface reflectivity and insulation thickness of external walls was examined to formulate an effective insulation strategy for buildings in Korea. Office buildings of 12 regions in the Korean Peninsula were considered. The dynamic energy simulation program EnergyPlus was used to perform the heating and cooling load analyses. The present worth method was adopted to perform the economic analysis. The analysis of the cooling and heating loads indicated that a change occurred not only in terms of the latitude but also between the Eastern and Western regions. The energy consumption could be reduced by increasing the reflectivity in the Southern region and lowering the reflectivity in the Northern region, based on the total load. In addition, a higher latitude corresponded to a higher energy saving effect owing to the increased insulation thickness. In the case of Jeju Island and Busan, regions with a relatively large cooling load and small heating load, the total load is little affected by insulation thickness at high reflectivity. If the external skin was considered to have the optimal reflectivity, the regions for optimal insulation thickness could be divided into three categories: north, central and south.