Alexis Pérez Fargallo

Alexis Pérez Fargallo
University of Bío-Bío | UBB · Department of Building Science

PhD in Construction Technology: Research, Development and Innovation

About

58
Publications
13,324
Reads
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658
Citations
Additional affiliations
March 2017 - present
University of Bío-Bío
Position
  • Professor (Associate)

Publications

Publications (58)
Article
Solar protections are often designed as passive strategies in buildings, both for thermal and lighting performance. In this sense, the importance of the balance between these two parameters could be crucial in the early stages of design. The purpose of this research is to compare the variation solar protection strategies (glazing with solar protect...
Article
Full-text available
Energy poverty (EP) is a problem that affects a large part of the world population, leaving those most vulnerable to suffer from unhealthy indoor conditions in their homes, being cold in winter months, struggling with their monetary situation, and even reducing social activities with relatives. In this context, it is important to assess EP situatio...
Article
Full-text available
In recent years there has been renewed interest in innovative solutions for coating mortars. Previous research has clarified the importance of substituting a percentage of cement by other binders, and thus focused on a good balance between structural and thermal properties. However, the effect on the economic cost and the carbon footprint is yet to...
Article
Full-text available
Human wellbeing and their quality of life is linked to daylight. However, this is being hindered by the rapid growth of cities, promoted by regulatory frameworks and the interests of property developers that seek high-rise densification and re-densification of certain urban areas, jeopardizing access to daylight. This article proposes a methodology...
Article
Domestic hot water (DHW) consumption in dwellings can play a key role in the development of policies that are focused on energy poverty, and in improving energy efficiency, among other aspects. There is an important variability observed with DHW among different countries due to technical, sociological, climatic, and economic factors. Most studies t...
Article
Full-text available
In recent times, studies about the accuracy of algorithms to predict different aspects of energy use in the building sector have flourished, being energy poverty one of the issues that has received considerable critical attention. Previous studies in this field have characterized it using different indicators, but they have failed to develop instru...
Article
Buildings are part of an energy-intensive industry responsible for a remarkable amount of the greenhouse emissions, therefore the European Union has launched in the last years an ambitious strategy to decarbonize buildings. Nevertheless, transnational policies based on technological upgrade might not be always effective, as in the case of Europe, N...
Article
Full-text available
Including recycled waste material in cement mixes, as substitutes for natural aggregates, has resulted in diverse research projects, normally focused on mechanical capacities. In the case of recycled glass as an aggregate, this provides a noticeable improvement in thermal properties, depending on its dosage. This idea raises possible construction s...
Article
Today, identifying energy poverty is one of the scientific community's challenges. In this sense, using Geographic Information Systems (GIS) assumes getting to know which areas are the most vulnerable. This study considers the development of a new territory energy poverty evaluation indicator, called Poverty Adaptive Degree Hourly Index (PADHI). Th...
Article
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This work presents an experiment where a constructive system with hollow blocks is assembled using a robot. These blocks form a stay-in-place support to receive a mixture onsite, generating a monolithic concrete wall with vertical steel reinforcements, as well as providing thermal and acoustic insulation capabilities. The assembly system is tested...
Article
Full-text available
Energy improvement studies normally use energy demand reduction as an indicator, disregarding dwellings that do not use airconditioning systems or do so only under extreme weather conditions. They also do not quantify the impact of climate change on results. This research seeks to evaluate and prioritize energy improvements for existing Uruguayan d...
Article
Adaptive comfort models have emerged as a sustainable way of providing comfort in connection with local climate. Additionally, climate change has posed an additional challenge. In previous studies, the authors clarified how climate change would affect the feasibility of the adaptive comfort model at a worldwide scale, but local considerations for s...
Article
Energy poverty (EP) occurs when there are no energy services available or not at an affordable price, or when homes are not capable of maintaining minimum thermal comfort conditions. It is associated with a series of adverse consequences for the people's health and with a higher number of deaths in winter in most European countries. The objective o...
Article
The recent development of the calculation methodology for dynamic thermal properties of buildings has opened new possibilities for reducing their energy demand; however, building codes still rely on the traditional static approach. This research aims at filling in this gap by exploring how periodic thermal properties can be implemented in the Spani...
Article
Full-text available
People's subjective response to any thermal environment is commonly investigated by using rating scales describing the degree of thermal sensation, comfort, and acceptability. Subsequent analyses of results collected in this way rely on the assumption that specific distances between verbal anchors placed on the scale exist and that relationships be...
Article
Full-text available
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Article
Full-text available
This research aims at clarifying the influence of the granulometry of expanded perlite, on the thermal conductivity, structural strength, density, and water absorption of lightweight mortars. Three original perlite gradations have been obtained and three pairs of twin test mortars have been tested with those gradations. SEM tests have also been run...
Article
Many studies are nowadays focused on the application of energy conservation measures (ECMs) to building sector because of the reductions of both greenhouse gases and energy consumption set by the European Union. Heating, Ventilating and Air Conditioning (HVAC) systems are the main causes of most energy consumption in the existing buildings. One o...
Article
Full-text available
Thermal discomfort is one of the main triggers for occupants’ interactions with components of the built environment such as adjustments of thermostats and/or opening windows and strongly related to the energy use in buildings. Understanding causes for thermal (dis-)comfort is crucial for design and operation of any type of building. The assessment...
Article
The building sector is among the main energy users in the world, and its consumption patterns are strongly affected by changes in climate conditions. The consumption prediction in future scenarios is one of the greatest challenges. The application of recent techniques, such as adaptive thermal comfort strategies, constitutes an opportunity to reduc...
Article
Many studies are focused on the diagnosis of fuel poverty. However, its prediction before occupying households is a developing research area. This research studies the feasibility of implementing the Fuel Poverty Potential Risk Index (FPPRI) in different climate zones of Chile by means of regression models based on artificial neural networks (ANNs)...
Article
Full-text available
Well cementing operations are crucial during the drilling and completion of oil wells. The cement sheath must have sealing ability throughout the well’s life and provide long-term zonal isolation in hostile downhole conditions to avoid potential remedial costs and environmental impacts. In the development of API cements, the reinforcement with disp...
Article
Heating, Ventilating and Air Conditioning (HVAC) systems represent one of the highest energy consumptions for office buildings. They are traditionally based on fixed setpoint temperatures during working hours and disregard outdoor conditions. The use of natural ventilation coupled with HVAC systems is frequently proposed when considering the global...
Article
Full-text available
Adaptive comfort plays an important role in defining comfort standards when considering comfort in buildings in free-running mode, including adaptation to external temperatures, opening windows and changing clothing. In this regard, two international standards provide the fundamental basis to model the necessary equations: EN 16798 (formerly 15251)...
Article
Fuel poverty is a pertinent issue for vulnerable households both in industrialized and developing countries, which is related to energy prices and accessibility of energy services. This research explores the feasibility of predictive models to prevent fuel poverty through the Fuel Poverty Potential Risk Index (FPPRI). Two statistical models, multip...
Article
Most of the operational energy needed by the housing sector is used to compensate energy losses or thermal gains through the building's envelope. As a result, any improvement in the thermal behavior will provide important opportunities to reduce energy consumption. This research analyzes improvements in the thermal envelope in social housing in the...
Book
This book explains how energy demand and energy consumption in new buildings can be predicted and how these aspects and the resulting CO2 emissions can be reduced. It is based upon the authors’ extensive research into the design and energy optimization of office buildings in Chile. The authors first introduce a calculation procedure that can be us...
Conference Paper
Los sistemas de tuberías enterradas con intercambiadores tierra-aire, conocidos en inglés como Earth Air Heat Exchanger (EAHE) o en español como tubo provenzal, pueden proporcionar una reducción de la carga de climatización en edificios situados en climas fríos, templados y cálidos. No obstante, su aplicación en climas tropicales no ha sido tan est...
Article
Building Simulation Software tools support designers to analyse and identify certain users´ behavioural patterns; besides, they can predict future trends about the energy demand and consumption in buildings, as well as CO2 emissions, design analysis, energy efficiency, or lighting. These tools allow to collect and report information about such proc...
Chapter
This chapter intends to develop a mathematical model that allows predicting, with an acceptable degree of uncertainty, the energy consumption and CO2 emissions for the office buildings in Chile. Through the multivariable regression method, diverse equations will be produced that will bear in mind the parameters mentioned for the different locations...
Chapter
This chapter intends to demonstrate the performance and reliability of ANN in predicting large scale data not only for a single parameter, but for three of them (energy consumption, energy demand and CO2 emissions) in relation to a large-scale sample of buildings, with all the issues associated to them, such as the nonlinearity of problems related...
Chapter
To evaluate the energy behavior of the buildings it is necessary to know numerous data related with its geometry, internal and external loads, construction systems, air-conditioning systems and user profiles. Selecting and quantifying the parameters needed is a complex task which requires the designer’s experience and knowledge, as well as an in-de...
Chapter
The energy demand analysis is performed following a methodology that comprises three main stages (Fig. 3.1). In the first stage, the input data for the simulation process is set up, making a distinction between two groups: Climate data and what has been called “test models”. On one side, the 9 different climate zones in which Chile is divided into...
Article
Full-text available
The incorporation of grounded construction and/or demolition wastes to cementitious conglomerates aims to achieve a positive environmental balance, so that the construction industry assumes wastes from different sources. Glass as a waste has a high recovery degree and numerous reuse possibilities. The glass residues incorporation to the cement mort...
Article
The evaluation of construction standards using adaptive thermal comfort models has a great impact on energy consumption. The analysis of a user’s climate adaptation must be one of the first steps in the search for nearly/net Zero Energy Buildings (nZEB). The goal of this work is to analyze the standards recommended by the Chile’s Construction with...
Article
Public housing policies face a challenge in order to meet not only the right to housing, but also an affordable and comfortable use for them. In this context, most of the studies related to fuel poverty are based on a diagnosis of existing conditions, but there is a lack of information focusing on how to predict the risk of fuel poverty in future d...
Conference Paper
Most of the operational energy needed by the housing sector is used to compensate energy losses or thermal gains through the building’s envelope. As a result, any improvement in the thermal behavior will provide important opportunities to reduce energy consumption. This research analyzes improvements in the thermal envelope in social housing in the...
Article
Currently, energy performance indicators for buildings are associated with the primary energy source consumption, CO2 emissions or net energy distribution, which together set the building’s energy efficiency. The evaluation is frequently based on setpoint temperatures and hours of operation. However, these fixed parameters are not suitable for soci...
Article
Fuel poverty is commonly associated with fuel price, energy consumption, income and building features to maintain comfortable conditions. Most studies are based on existing conditions with future macro level predictions. Therefore, there are a lack of micro scale policies and further in-depth research is needed based on the multivariable complexity...
Chapter
Full-text available
In recent years climate change has brought to light a rising interest on its potential impact amongst the various human activities, in which building sector is included. Local climate determines the external conditions that buildings have to adapt to, having a direct influence on their energy demand for heating and cooling. In this context, compute...
Article
The reduction of energy consumption and CO2 emissions in buildings has become an essential field of study in the recent years. Simplified design tools, used in the first design stages, can be of great help in adopting concrete decisions that will, at the end, allow these to be reduced. This paper presents a new predictive model for office buildings...
Conference Paper
Full-text available
Previous studies based on simulation carried out in the context of temperate climates in Chile have shown that an insulated and sealed thermal envelope, solar control devices and ventilation strategies would allow to achieve good thermal conditions with no heating and cooling systems. This paper is based on a fieldwork that analysed two school buil...
Article
Full-text available
The aim of the article is to study the energy efficiency improvements feasibility through the analysis of energy savings and economic investment. The results were obtained from a model studied with different orientations, building systems and interventions, including two retrofit options regarding thermal transmittance, specified in Appendix D of t...
Conference Paper
Full-text available
The constructive configuration of an educational institution influences its indoor comfort variables; while at the same time comfort variables have an effect on the metabolism and stress of students and teachers. In turn, each architectural project depends on the factors that define its design. When the investment is assessed, costs are determined...
Article
Full-text available
Energy efficiency in the residential sector is one of the priorities of the European Union. It is estimated to achieve an energy saving of 27% in the group of buildings in the residential sector in the EU countries by 2020 through the directives issued by the European Commission. The housing stock of Spain are among the least energy efficient in Eu...
Conference Paper
Reducing the energy consumption of the residential sector is one the main objectives of the UE, which planned to reach 27% of energy saving for the residential building sector in 2020 through European directives regarding energy efficiency. The Spanish government is encour-aging official grant in order foster the thermal refurbishment of residentia...
Article
Full-text available
El artículo analiza la integración de la Universidad de Sevilla, como organismo disperso en la ciudad, desde la óptica de la sustentabilidad. Las actividades universitarias deben dar lugar a hábitats desarrollados a partir de un objetivo de calidad urbana y con una voluntad de integración en la ciudad, dando lugar a una puesta en valor del entorno...
Conference Paper
Full-text available
Homes are one of the major energy consumers and generate significant environmental impact in Chile and globally. The improvement of existing buildings or new projects is a procedure based on multidimensional simulations and the energy evaluation of housing. However, there is a lack of strategies to identify appropriate modifications. Normally, the...
Article
Full-text available
This paper analyzes the sustainable integration of the University of Seville in the urban layout. University activities must generate high quality spaces and environments, while preserving the architectural and cultural value of the city. The analysis of this university model with a dispersed structure developed over centuries makes it possible to...
Article
Full-text available
El artículo analiza la configuración territorial y espacial de una universidad policéntrica, centrándose en el caso de la Universidad de Sevilla, como organismo disperso en la malla urbana. Su objetivo es presentar tal modelo para comentar y discutir las ventajas e inconvenientes que surgen tanto a la universidad como a la ciudad, al implantar una...

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Projects

Projects (5)
Project
RIPEBA es una red del programa CYTED integrada por investigadores de Argentina, Chile, Colombia, Costa Rica, España, México, Portugal y Uruguay. Tiene como objetivo el estudio, evaluación y generación de indicadores y estrategias de diseño y construcción sostenible con el fin de reducir la pobreza energética en Iberoamérica, mejorar el bienestar ambiental y promover el uso de energía limpia y segura en un escenario postpandemia, así como incrementar la trasferencia de conocimientos y tecnologías.
Project
In recent years, providing a comfortable and low energy indoor environment has become a challenge in the building sector. In this context, adaptive comfort plays an important role, including adaptation to external temperatures, opening windows and changing clothing. Considering the global tendency towards reducing energy consumption in buildings, the use of natural ventilation coupled with HVAC systems is frequently proposed. Numerous methods have been proposed in order to provide acceptable comfort levels considering a rational use of energy (i.e., adaptive control algorithms, building automation systems, etc.). However, there is no consensus on comfort thresholds, and it is difficult to predict energy consumption. Likewise, climate change will play an important role, since it will change the trends in energy consumption of buildings. This Special Issue focuses on the understanding of adaptive comfort in buildings coupled with the energy in use and the possibilities to reduce energy poverty and obtain a low-carbon building stock. https://www.mdpi.com/journal/applsci/special_issues/Thermal_Comfort_Climate_Change_Buildings
Project
In 2014, the Chilean Energy Ministry presented the Energy Agenda, with one of the tasks designing and implementing an Energy Policy. The new Energy Policy 2050 is based on four pillars. One of the guidelines was defining the concept and measuring energy poverty (EP) to set policies to reduce it. There are different international indexes and indicators to measure EP, but this is a relative concept with variables changing depending on where it is being observed. Chile has made progress, with an EP Three-Dimensional Index created by the EP Network; however, this index still needs local adaptation considering the home's occupation and usage. Most EP indicators do not consider that poorer people adjust comfort levels to reduce energy consumption, and the ones that do, are unvalidated theoretical indexes which ignore other consumptions. This proposal's hypothesis is that it is possible to predict, using the basic information of the dwelling (orientation, surface in contact with other homes, indoor volume, urban geometry, energy or fuel price) and the family group living there (number of members and incomes), the risk that they experience energy poverty, using statistical models with a coefficient of determination above 95%. The project's general goal is developing a predictive indicator and application models which, using the dwelling and family's basic information, are capable of analyzing existing buildings, helping allocate or choose new social housing (SH) and, assess standards to reduce energy poverty risks in Central and Central-Southern Chile. The following are considered as specific goals: 1. Collecting primary data, using onsite measurements and surveys, regarding architectonic, constructive and indoor environment characteristics (temperature, humidity, intra-household contamination) of different social housing typologies, as well as data regarding energy needs (equipment, access, interruptions, sources, capacity and energy expenses), economic and social aspects of families living there (incomes, expenses, use of dwelling and demographic data). 2. Determining factors to fit simulation data to real data, to adjust energy simulations of dwellings built using current (TR) and new construction standards (NTM 11-2 and ECSV). 3. Developing a predictive energy poverty risk using the data collected aligned with energy poverty three-dimensional index, generating information, and making its use in other social situations, SH typologies, materialities and geographic areas possible. 4. Establishing and validating mathematical models that allow using the index proposed more simply, to analyze existing buildings, help allocate or choose new social housing and assess standards to reduce energy poverty risks. 5. Developing tools for dissemination and use along with recommendations for their implementation in the legislation applicable to the construction, acquisition, rental or modification of social housing in Chile. The proposal has 5 stages (13 activities). Stage 1 comprises designing and validating data collection tools, identifying statistically representative SH typologies and onsite primary data collection. Stage 2 comprises simulating the dwelling's resulting energy use to set adjustment factors that allow calibrating the simulated consumption with real consumption. Stage 3 focuses on reviewing models and criteria to measure and assess EP, to establish the risk indicator with data collected onsite. This will be reported and validated to align with results from University of Chile's RedPE. Stage 4 will comprise simulating SH with current and new construction standards, generating mathematical models to predict EP risk in SH decision stages or to assess existing housing to focus thermal retrofitting resources or other subsidies. Stage 5 will comprise a digital platform to report the results. This will contain an interactive tool so that users can identify their EP risk. The Fuel Poverty Assessment Tool (https://www.nea.org.uk/fuel-poverty-assessment-tool-home/) is a good example. In addition, 3 JCR (ISI) articles, 2 congress appearances, one book, 10 talks in local councils and 1 seminar with ministerial authorities (MINVU, MINERGIA, MDS, MINISTRY OF HEALTH AND MMA) will be used to show the results. The expected results will be a predictive indicator and models to predict the risk of experiencing EP in Central and Central-Southern Chile and preparing recommendations and tools for its use and implementation in Chilean social housing legislation. As a result applicable to all regions, it is expected to obtain the methodology and experience needed so that the study can be replicated nationally, confirming that it is viable to standardize the indicator and the models for the entire country.