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[Display omitted] • Building policies must be rooted in a good understanding of the targeted population. • Building performance standards may benefit from creating databases of weather files. • A thermal performance analysis should consider multiple key performance indicators. • Building performance policies should address the thermal resilience of buildings. This paper presents the main challenges faced and lessons learned when developing a new method to assess the thermal performance of residential buildings for the recently updated Brazilian building performance standard, NBR 15575–1:2021. It touches on subjects related to the representation of occupant behavior, climate, and thermal acceptability in building performance simulation, as well as the use of reference models, key performance indicators, and performance levels in policies. NBR 15575 provides a thorough procedure to analyze thermal performance, allowing buildings to be assessed while in passive operation mode and also accounting for energy needs when active operation is necessary. Multiple key performance indicators are introduced to provide a comprehensive evaluation. The main difficulty found was dealing with diversity. Given the vast scale of Brazil's territory, a high variation in culture, climate and construction techniques is expected, thus requiring a compromise between detail and scalability. There are still many opportunities for improvement, especially regarding the representation of occupants, and adjustments of the characteristics of reference models to promote high thermal performance, considering the diverse climates, regional practices, and economic needs. This paper might help researchers and other stakeholders to develop and improve other local standards and protocols, especially for warm climates. [ABSTRACT FROM AUTHOR]

Abstract Dwellings with no heating, ventilation and air conditioning (HVAC) systems are commonly found in many countries. The long-term thermal performance of these buildings can be assessed based on hourly data of occupant thermal discomfort integrated over the required timespan (e.g. total degree hours of discomfort per year). This approach can be easily applied when simulation is adopted in the assessment, but field studies using this approach are rare as they would require complex, costly and long measurement/survey campaigns. This paper addresses the challenges on conducting field studies on long-term thermal performance of dwellings with no HVAC system by introducing a novel performance indicator: the Seasonal Thermal Sensation Vote (S-TSV). S-TSV adopts the standard 7-point thermal sensation scale and is based on the perceived overall thermal sensation recalled by the user of the building for specific seasons and times of day. The new performance indicator is not intended to replace existing ones, but to complement them in the understanding of the complex thermal performance processes taking place in buildings with no HVAC. S-TSV was applied in a field study targeting a small sample of dwellings in Brazil. Results demonstrate the capabilities of S-TSV to describe trends in buildings performance in this sample. S-TSV also assisted on the identification of relationships between such performance and some independent variables addressed in this field study (e.g. windows operation, footwear and income), considering a threshold of p -values <0.05 on the chi-square statistic test. [ABSTRACT FROM AUTHOR]

Highlights • Cost-effective abatement opportunities to reduce CO 2 emissions are assessed. • Reference and low-carbon scenarios are defined by using a bottom-up model. • Abatement opportunities are assessed for the Brazilian residential sector. • Cooking and PV solar represent more than 70% of the abatement potential. • Policies must focus on budget constraint, upfront cost and high interest rates. Abstract This paper assesses cost-effectiveness of abatement opportunities to reduce CO 2 emissions in the Brazilian residential sector and proposes policies to support their implementation. Findings show that, if implemented, the energy efficiency measures in the cooking end-use and photovoltaic (PV) solar panels would represent together more than 70% of the abatement potential. Assuming the implementation of all measures, the energy consumption in 2050 would increase only 18% in relation to 2010. The total avoided emissions would be 642 MtCO 2 in Brazil over the 2010–2050 period. The implementation of the measures face barriers related to market, financial, energy costs, technological and cultural or informational issues. Besides the Brazilian Labeling Program (PBE), more aggressive standards are required. Financial barriers, especially those regarding the budget constraint, upfront cost and high interest rates in the residential sector, must be overcome. [ABSTRACT FROM AUTHOR]

Highlights • Cool roofs can improve thermal comfort of low income households near the equator. • Experimental results in Jamaica confirm improvements. • Energy models were developed for Jamaica, Ghana and Recife-Brazil. • Internal ceiling surface temperatures are reduced on average by 3.2–5.5 oC. • Cooling demand reduction is similar at 190 kWh/m2/year. Abstract Cool roofs are most effective in reducing cooling loads and alleviating overheating in locations with high solar radiation and external air temperature. This paper presents results of an experimental study of a low income house in Jamaica and a computational study in three countries around the equator: Jamaica, Northeast Brazil (Recife) and Ghana. A case-study typical of single storey houses in Jamaica was monitored before and after the installation of a cool paint on the roof; on days with average solar radiation intensity of ∼420 W/m2 and ambient air temperature of ∼28 °C, internal ceiling surface temperature is reduced by an average of 6.8 °C and internal air temperature by 2.3 °C. Monitoring results were used to calibrate successfully an EnergyPlus model; similar models were developed for Ghana and Brazil differing in size and/or construction to reflect country specific practices. Annual simulations indicate that internal ceiling surface temperatures are reduced on average by 3.2–5.5 oC and internal air temperatures by 0.75–1.2 °C. Cooling demand simulations (setpoint 24 °C) indicate similar annual potential savings in the three locations (∼190 kWh/m2/year) although estimated CO 2 emissions reduction differ reflecting electricity generation fuels. Aging of the cool roof has an impact reducing load savings by 22–26 kWh/m2/year. [ABSTRACT FROM AUTHOR]

Social housing sector is very important in Brazil, due to the necessity of expansion and investments being placed through a substantial government program. Residential buildings are expected to last at least 50 years according to Brazilian standards. Many residential projects in the sector already perform medium or poorly in terms of energy efficiency and thermal comfort today, and their designs are not analysed considering climate change. Therefore, the aim of this paper is to investigate the result of analysing the thermal and energy performance of social housing projects considering climate change, and to assess the impact on the operational phase of introducing energy efficiency measures in the sector, and exploring methods of adaptation to climate change. A representative project of the lower income sector housing was used as case study with the evaluation of measures through thermal and energy simulation with current and future weather files for the cities of São Paulo and Salvador. Results were compared using predicted energy consumption and cooling and heating degree-hours as indicators. The results highlighted some differences related to the climate scenarios and indicator analysed, and showed that the incorporation of energy efficiency measures in current social housing projects is of fundamental importance to minimize the effects of climate change in the coming decades. [ABSTRACT FROM AUTHOR]

It is known that building performance usually involves different criteria such as the energy consumption, thermal comfort, thermal loads and internal temperatures, which can make its assessment more complex. Thus, this paper aims to describe a decision-making process to improve some criteria related to the energy efficiency of residential buildings considering a multicriteria approach. Computer simulation using EnergyPlus v8.3-2014 was performed to assess the thermal and energy performance of a residential building for four different climates in Brazil (Belém, Campo Grande, Curitiba and Florianópolis). The performance criteria were the degree-hours and energy consumption for air-conditioning (both for heating and cooling) in different decision makers’ preference scenarios. The performances of eight constructive systems were evaluated considering uncertainties related to the operational variables of the building, obtained through field survey. The results showed that some systems had statistically equivalent performance considering the range of uncertainty. The system of masonry with double massive brickwork performed better for three climates; for Belém, however, an adequate system highly depends on the preference scenario. Nonetheless, different preference scenarios would indicate different adequate systems for all climates. This study used a method of decision-making which enables the possibility for future analyses of other performance alternatives, design variables, and performance criteria. [ABSTRACT FROM AUTHOR]

Abstract: This paper reports the use of an internationally recognized validation and diagnostics procedure to test the fidelity of a simplified calculation method. The case study is the simplified model for calculation of energy performance of building envelopes, introduced by the Brazilian regulation for energy efficiency in commercial buildings. The first step of the assessment consisted on evaluating the simplified model results using the BESTEST. This paper presents a straightforward approach to apply the BESTEST in other climates than the original one (Denver, USA). The second step of the assessment consisted on applying the simplified model to evaluate four building typologies, and compare the results with those obtained using a state of the art building energy simulation (BES) program. For some BESTEST cases, the simplified model presented results inside of a confidence interval calculated by the authors. However, the simplified model was found to yield significant difference in the four building typologies analysed. Moreover, in all four building typologies analysed, the simplified model led to a lower energy efficiency label when compared to the label obtained using BES. The paper concludes that the simplified model may require improvements to properly indicate the actual energy performance of commercial building envelopes. [Copyright &y& Elsevier]

• A top-down analysis of the non-residential building stock in Brazil is proposed. • The share of each building typology in the country energy consumption was assessed. • A statistical analysis showed variation of EUI according to type of building and region. • Reference values for the commercial building stock in Brazil is provided. This paper provides a pioneering, top-down analysis of the non-residential building stock in Brazil. A country-wide dataset was used, comprising 10,000 buildings divided into 12 typologies. Key indicators include floor area, energy use intensity, and operation patterns. In addition, predominant wall constructions, lighting systems, equipment, water heating, and HVAC systems for each typology were identified, including average density power for the systems. Data from the Brazilian Energy Balance report was correlated with the sample of buildings to determine the proportion of each building typology in the total energy consumption of the country, considering different energy sources. This study provides an innovative and up-to-date status of the characteristics of non-residential buildings in Brazil. A complementary statistical analysis addressed the correlation between energy use intensity and the building characteristics including an ANOVA test and a regression analysis in order to investigate the influence of the energy usage indicators (Lighting Power Density, Equipment Power Density, Cooling capacity) on the energy use intensity of each building typology in Brazil. This study is intended to serve as a reference for building characteristics and building energy performance in Brazil, and hence support diverse research regarding country-level building stock modeling, energy benchmarking, climate change impacts, and energy-efficiency related studies. [ABSTRACT FROM AUTHOR]

The proposition of Net Plus-energy Buildings (NPEB) leads to the need to carry out studies of load matching in contrast with the grid impacts of distributed generation (DG). This paper performs simulations with the EnergyPlus software tool concerning a NPEB operating in four Brazilian metropolitan areas. The analyses include photovoltaic (PV) performance parameters and Load Matching and Grid Interaction indicators (LMGI). New grid impact indicators are defined in order to study the impacts of DG in the power grid. In the second stage, the work investigates economic aspects under net metering supporting. Results show the annual amount of electrical demand covered by PV varies from 29 to 51% with more potential in situations with higher PV production and higher cooling load, and the annual PV electricity that supplies the loads varies from 24 to 36% according to the seasonal variations of PV-load correlation. The levels of exported electricity into the grid are high in Brazil with annual mean power peaks surrounding 0.7 but can surpass 0.8 in the sunniest periods. The economy demonstrates the building achieves grid parity from 6 to 18% discount rates and the payback time is given for different scenarios of investment costs, discount rates and electricity tariffs. [ABSTRACT FROM AUTHOR]

This paper describes the development and focus in the analysis of the Brazilian metamodels used in the residential labeling system. The metamodels represent the thermal behavior of naturally ventilated and artificially air-conditioned residential buildings. A computational simulation experiment using the EnergyPlus program was conducted taking into account naturally ventilated and artificially air-conditioned residential buildings. Several parameters were considered for parametric simulations such as thermal transmittance, thermal solar absorptance, shading device, ventilation opening factor. The multi-linear regression method was used to predict the cooling degree hours and the annual energy consumption for heating and cooling for dormitories and living room. An assessment on the accuracy of the Brazilian metamodels for residential buildings was analyzed and showed that the regressions include standard errors that may influence the metamodels accuracy. Therefore, artificial neural networks (ANNs) are presented as an alternative to improve the metamodels used in the Brazilian regulation. Comparing both statistical method multi-linear regression and artificial neural network method it can be seen that ANN presented lower results for standard deviation end root mean square errors. Therefore, ANNs are recommended to improve the accuracy of the prediction in further behavior associated with the labeling system. [ABSTRACT FROM AUTHOR]

• An overall panorama of the school buildings in Brazil was presented. • Energy billed data and survey evidence were used to build a statistical stock model. • The Weibull distribution was the most adequate to represent the continuous variables. • kWh/student·year was more suitable than kWh/m2·year to model Brazilian school buildings stock. • Thermal performance is an issue to be greatly improved in schools in Brazil. Understanding the actual conditions in school buildings regarding energy usage and environmental satisfaction gives way to the development of consistent building stock modelling. In the Brazilian context, a deep-rooted inefficient structure of energy management implies a lack of mapping the actual conditions of the public schools. Therefore, this paper aimed to assess the actual energy performance of school buildings in Brazil. This paper innovates by integrating questionnaire responses and billed energy data to allow the construction of an evidence-based stock model through a statistical approach, which was never performed for the Brazilian building stock. Moreover, the association of energy use intensity (EUI) with the core aspects of building characteristics, occupancy, environmental satisfaction and necessary improvements mapped the relevance of such aspects in energy usage patterns. Additionally, a discussion of the EUI indicators was addressed. Results showed an unprecedented broad panorama of the school building stock in Brazil and its main features. In terms of statistical analysis, the Weibull distribution was appropriate for representing the continuous variables of the stock. The EUI as a function of the number of students was more suitable than the floor-plan area to achieve a reliable energy performance analysis. Several tests were performed to assess if the energy management, environmental satisfaction and maintenance practices impacted the EUI or not. Finally, the main conclusion was that the stock model obtained was simple and fit the energy management structure in the Brazilian scenario. [ABSTRACT FROM AUTHOR]

This paper departs from a planning tool to assist policy makers and energy planners to improve energy access and affordability, besides developmental needs of low-income/underserved households and small entrepreneurs. The methodology aims to systematically integrate energy technologies (supply and demand-side), new and innovative business models and local developmental issues into long term power plans by applying concepts and the process known as Integrated Resources Planning (IRP). To illustrate the application of the methodology, referred to as IRP-Access in this paper, some possibilities are tested to reduce Energy Service Costs (EC), analyzing the impacts in the electricity affordability of low-income consumers. For this purpose, we use data from a Brazilian electricity concessionaire which operates in a complex socioeconomic region in the Southeast of the country, where the energy access is solved, but affordability is still a current issue. The results illustrate the potential of implementing technological alternatives in Brazil, from the supply and demand side, in order to improve affordability, to address energy poverty and to systematically incorporate such critical issues into the long-term energy planning. [ABSTRACT FROM AUTHOR]

Abstract: The Brazilian government has started up a large social housing program for low-income families. Considering the large investment for this program, it is important to analyse the environmental impact to create a base for further improvement assessment. The goal of this paper is to visualise the energy use (embodied and operational) during the life cycle of case study for a house in the social housing program. The case study showed that the embodied energy (EE) is 7.2GJ/m2 or 30% of the total energy from the life cycle, the operational energy is 17.5GJ/m2. Half of the Embodied Energy is due to material use for maintenance and around 57% of the embodied energy is used in the wall construction. Compared to other international studies (5.8GJ/m2 per 50 years), the embodied energy is relative high (7.2GJ/m2 per 50 years) whereas the operational energy is only the half (17.5 compared to 36GJ/m2 per 50 year). The study indicates that the largest improvement potential for reducing the embodied energy is connected to the walls trough choosing materials and systems with less Embodied Energy and higher durability to decrease the need for maintenance and substitution of materials. [Copyright &y& Elsevier]

Abstract: In Brazil, a low-latitude country characterized by its high availability and uniformity of solar radiation, the use of PV solar energy integrated in buildings is still incipient. However, at the moment there are several initiatives which give some hints that lead to think that there will be a change shortly. In countries where this technology is already a daily reality, such as Germany, Japan or Spain, the recommendations and basic criteria to avoid losses due to orientation and tilt are widespread. Extrapolating those measures used in high latitudes to all regions, without a previous deeper analysis, is standard practice. They do not always correspond to reality, what frequently leads to false assumptions and may become an obstacle in a country which is taking the first step in this area. In this paper, the solar potential yield for different surfaces in Brazilian cities (located at latitudes between 0° and 30°S) are analyzed with the aim of providing the necessary tools to evaluate the suitability of the buildings’ envelopes for photovoltaic use. [Copyright &y& Elsevier]

Abstract: Electric energy prices in Brazil are higher during 3h of peak consumption on working days; however, consumers could use a generator system for partially reducing the electricity costs from utility company during peak hours. The process of sizing a generator system begins developing the so called load capacity curve, using acquired building electricity consumption data. The local utility company supplies this data only for the last month of operation; consequently, data are unavailable for the rest of the year. In order to overcome the difficulty, this paper develops two methodologies to estimate the curve for every month of the year. The first one uses the frequency of occurrence of the measured values of the load power in each bin and the last one the monthly values of load power and energy consumption, as supplied by the local utility monthly bills. In order to validate the methodologies, monthly utility bills and consumption data of electric energy measured at Pontifical Catholic University of Rio de Janeiro, every 15min over a four year period, have been used. Finally a generator system was sized, minimizing the electrical energy cost supplied by it, when the generator meets partially the building load. [Copyright &y& Elsevier]

Abstract: Green roofs have been investigated as a bioclimatic strategy to improve the energy efficiency of buildings. Quantitative data on this subject are still needed for many specific climatic conditions. This paper deals with the investigation of the green roof thermal performance of an experimental single-family residence in Florianópolis (SC, Brazil), a southern city with a temperate climate. Field measurements during a warm period (01-March-2008–07-March-2008) and during a cold period (25-May-2008–31-May-2008) included internal air temperature of rooms, internal and external surface temperature of three types of roofs (green, ceramic and metallic), heat fluxes through these roofs, green roof''s temperature profile, water volumetric content in substrate layer and meteorological data. During the warm period, the green roof reduced heat gain by 92–97% in comparison to ceramic and metallic roofs, respectively, and enhanced the heat loss to 49 and 20%. During the cold period, the green roof reduced heat gain by 70 and 84%, and reduced the heat loss by 44 and 52% in comparison to ceramic and metallic roofs, respectively. From the derived data it has been confirmed that green roof contributes to the thermal benefits and energy efficiency of the building in temperate climate conditions. [Copyright &y& Elsevier]

Abstract: This paper addresses the application of Energy Efficiency Rating Technical Quality Regulations for Commercial, Service and Government Buildings – RTQ-C in order to ascertain whether the conventional construction system for buildings complies with these requirements. Additionally, it investigates the contribution of labeling to reducing electricity consumption by the building. To do so, the RTQ-C was applied to two buildings in order to calculate the efficiency levels of their envelopes and possible alterations are proposed for upgrading the envelope performance where pertinent. It is noted that conventional buildings adopting measures such as painting the walls and roof white, in addition to using smoked glass, are sufficient to bring the rating up to an A grade. As no specific concern was noted in the architectural designs for the buildings studied, making use of design strategies that minimize the use of electricity in these buildings, the findings of these case studies may well indicate that the RTQ-C has adopted technical requirements that are not particularly stringent. Consequently, it is believed that these requirements should be reviewed during a second stage, in order to make them more restrictive and attain further improvements in the constructed environment with better energy efficiency for buildings. [Copyright &y& Elsevier]

Abstract: One of the variables that have a greater influence on the determination of the moisture buffering capacity of a material to be used as inner surface layer of an enclosure is the value of the vapour resistance of the surface film layer. In this paper, the influence of such a surface resistance on the moisture buffering value (MBV) is studied by means of a small experimental equipment where the tests were developed according to the NordTest protocol, but modifying the air speed over the samples, in order to take in count its influence. The tested material is an autoclaved ceramic made from the shells of the molluscs grown in Brazil, with the aim of using it as indoor surface layer of the enclosures in museums and buildings used to keep archives and documents, and where it is required to control the conditions of the indoor air by means of passive systems based on the moisture buffering capacity of the materials. The theoretical MBV is determined too based on the effusivity of the material which is obtained from its basic hygroscopic characterization. [Copyright &y& Elsevier]

The main purpose of formulating methodologies for building systems’ evaluation in low-cost housing is to find an effective solution for the huge Brazilian housing deficit of approximately five million housing units, mainly due to an accelerated population growth in urban centers. Low-cost housing programs are usually implemented in a broad sense, with no regard to local specific conditions. Thus, building systems of quite similar characteristics are employed in places with different climatic conditions, which leads to low-quality houses that do not respond to the users’ needs. In this paper, the results of the application of formulas to predict daily indoor temperatures in three monitored low-cost houses in Curitiba, Brazil, are presented. The houses were occupied by families having neither cooling nor heating devices and are built of different building materials with different thermal properties. The monitoring of the houses took place both in winter and in summer. Measured data were also compared with simulated data. In this case, the French software COMFIE was used. Finally, the results of the thermal simulations were compared with those of predictive formulas developed by Givoni. [Copyright &y& Elsevier]

• This paper focuses on extensive green roofs and their effect on indoor thermal comfort in a housing project. • Coupled simulations were performed linking outdoor microclimate and indoor thermal comfort calculations. • A ceramic tile and a green roof were compared in an original site and a green site (with trees and grass). • The microclimate around the house affects the effect of the green roofs on indoor thermal comfort. A comprehensive understanding of the effect of green roofs on the indoor thermal comfort, under different microclimates, will help to identify key design aspects. In this study, which is the first of its kind in Brazil, the indoor thermal comfort for two different types of roofs, under different microclimates in Porto Alegre in Southern Brazil, have been compared. Coupled simulations using ENVI-met and EnergyPlus linked calculations of outdoor microclimate and indoor thermal comfort. The site was approximately 100 m by 100 m with 24 one-story, naturally ventilated semi-detached houses with an area of 39 m2. One of the houses, located approximately in the middle of the site, represented the building scale. In the original site (with no tree shadings), the substitution of the ceramic by the green roof led to an increase of 9.1% of the time within the thermal comfort zone. This study helps to bridge the current gap between thermal simulations in different scales. Moreover, this investigation concluded that green roofs performed better when in a green environment: for the summer season, with trees partially shading the roof, the green roof resulted in a reduction of the maximum operative temperature by 4.3 °C, whereas for the site without trees, the reduction was 2.8 °C. [ABSTRACT FROM AUTHOR]

The energy performance of 11 bank branches in the Brazilian city of Curitiba was analysed using bottom-up engineering energy benchmarking method. As part of a previous study to classify bank buildings, these bank branches were selected for a further study with their building parametric and energy-related data obtained from building drawings and specifications as well as on-site surveys. The energy assessment of these branches was conducted using the existing (RTQ-C) and proposed (INI-C) Brazilian energy efficient labelling regulations for non-domestic buildings. The ability of both systems to produce results which are compatible and could be used to reflect the actual building energy consumption was examined. The study shows improvement of the INI-C system with calculation of energy consumption values and conditions for different reference buildings. However, performance gap between the calculated and actual energy consumption was found due to various reasons including reference values for office buildings were inaccurate for bank buildings. Hence, a list of modified reference values was proposed for bank buildings to represent bank buildings more accurately. This paper highlights the strengths and limitations of both the existing and proposed regulations and presents a reality check against the calculations of energy ratings and actual energy consumption of the buildings. It was concluded that the existing and proposed regulations have to be improved significantly in terms of calculation methodology in order to meet the demand of future energy policy in Brazil. [ABSTRACT FROM AUTHOR]