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.
 

This study presents a methodology to measure the impact of solar heating systems, on reducing peak demand and on avoided emissions, when applied in low-income housing projects. To this end, a real-time monitoring system was implemented over a year in five clusters representative of a heterogeneous socioeconomic context in new housing subsidized with solar water heating system through the national program “My House, My Life”. The results showed an expressive contribution of the system in reducing the maximum peak demand, obtaining, on average, a 64% reduction in relation to the electric showerhead, predominantly used in the country. The cumulative energy savings of 577 kWh per year resulted in an average of 250 kgCO 2 avoided per housing unit. The extrapolation of the data to 224,000 units already delivered by the national program would result in an economy of 56,089 tCO 2 per year. This study demonstrates the importance of measurement as a strategic tool in public policies for energy efficiency and in the estimation of emissions associated with greenhouse gases. The solar heating system positions itself as an important energy efficiency policy for Brazil, which minimizes the demand for thermoelectric plants during peak hours and postpones investments with new power generation plants.
 

Occupant behaviour has a direct impact on building energy consumption. A better understanding of human-building interactions enables to describe with higher accuracy the occupant behaviour. This paper addresses occupant behaviour in residential buildings, providing a review of current methods in (1) monitoring occupant behaviour, (2) developing occupant behaviour models, and (3) applying occupant behaviour models in building performance simulations. Occupant behaviour studies with focus on residential buildings are presented including both challenges and potential for improving building energy performance.

A multi-parametric sensitivity analysis of Solar Water Heater (SWH) systems was undertaken for the city of Brisbane in Australia using computational models calibrated by experimental data. The models were calculated using EnergyPlus 8.6. The following technical specification parameters were assessed in the modelling: (i) solar collector efficiency; (ii) solar collector area; (iii) tank volume; (iv) tank heat loss; (v) electric back-up heating power rate; (vi) electric back-up heating position (height) for vertical tanks; and (vii) electric back-up heating temperature range. The site-specific parameters included: (i) solar collector direction; (ii) solar collector tilt angle; (iii) solar collector shadowing; (iv) solar collector dust accumulation; (v) hot water pipe insulation; (vi) hot water pipe length; (vii) electricity tariff time-of-use; and (viii) cold water temperature. User behaviour patterns were comprised of the following parameters: (i) end-use water temperature; (ii) end-use water demand; and (iii) end-use time-of-use. For all parameters, two system types were assessed, namely: (i) thermosiphon systems with natural (passive) circulation in collectors and unstratified horizontal hot water storage tanks; and (ii) split systems with forced (pumped) circulation in collectors and stratified vertical hot water storage tanks. The performance of SWHs was analysed considering both energy performance indicators (i.e. total and peak-hour energy consumption, solar fraction and energy intensity) and level of service indicators (i.e. compliance with recommended hot water temperatures for Legionella spp. control and comfort levels). Notwithstanding the prevalence of thermosiphon systems among SWH technologies, results indicate that split systems usually outperformed thermosiphon systems both in terms of energy efficiency and level of service, and hence should be a preferred option for energy efficiency initiatives and policies.

The human dimension plays an essential role in the energy performance of buildings and is considered as significant as technological advances. Several studies highlighted the negative influence of occupant behaviour in underperforming buildings, while some support that technological innovations may reduce human-related uncertainties. Thus, one may consider that fully automated smart buildings are essential to achieve energy efficiency. However, if technology excludes people from decision-making processes, low acceptance and comfort/welfare levels may be reported from users. Therefore, the right combination of humans and technologies are expected to solve these problems. Buildings are emerging as complex Cyber-Physical Systems, including the Social dimension, and this provides an excellent opportunity to achieve high-performance outcomes, considering both technical and social aspects. Thus, the right choice among available up-to-date behavioural sensing – comprising active and passive sensors, as well as Kinect technology – are important in the Internet-of-Things (IoT) era. IoT-driven buildings can use real-time monitoring data to inform users and drive behavioural-based consumption change, which is an important aspect to achieve high-performance buildings and deliver user-centred services. An essential feature in this regard is to allow for human-in-the-loop approaches enabled by human-centric computing and smart devices, which has grown fast in the last few years. This literature review summarises applications and main challenges related to the combination of the human dimension and technological innovations in the building sector. This combination is expected to increase user welfare and reduce the energy consumption in buildings, as human and machine components of intelligence may complement each other regarding building performance.

Different stakeholders are involved in the energy consumption in buildings: occupants, designers, managers, operators, policymakers, technology developers and vendors. Therefore, it is necessary to understand their opinions and needs to optimise the energy consumption in buildings during their lifespan. Questionnaires and interviews have been applied; however, the literature still supports that energy research lacks social science approaches to improve their outcomes. Although limitations are inherent in qualitative methods (e.g., social desirability bias), much information such as human needs, preferences and opinions cannot be obtained through quantitative methods like building monitoring. Therefore, to have a deeper understanding of human-related aspects regarding the energy consumption in buildings, this literature review synthesises opportunities and main challenges of applying methods commonly used in social sciences. We reviewed papers published over the last five years (from 2014 to 2019) and presented information about questionnaires, interviews, brainstorming, post-occupancy evaluation, personal diaries, elicitation studies, ethnographic studies, and cultural probe. Increasing use of qualitative methods is expected to support the spread of human-centric policies and design/control of buildings, with a consequent overall optimisation of energy performance of buildings as well as the comfort of occupants.

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.

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.