Natural ventilation in Brazilian homes: depicting perceptions, usage patterns and motivations in a questionnaire survey

Autores:
Carolina Buonocore, Luiza Castro, Renata De Vecchi, Roberto Lamberts, Saulo Güths
Evento:
Building Research & Information
Resumo:

Natural ventilation is a default conditioning strategy in the Brazilian residential sector, while fans and air conditioners are complementary strategies. However, climate change and the increasing air conditioning penetration in this sector threaten the prevalence of natural ventilation and the potential wind-driven (breeze) performance on households’ thermal comfort. A questionnaire survey launched across Brazil assessed multiple aspects of natural ventilation at home: perceptions, usage patterns and motivations behind its use or avoidance. Data analysis methods were multinomial logistic regression and contingency tables of categorical data. The findings indicated that households’ preference for a conditioning strategy related to income and energy-saving concerns (economic aspects). The frequency of use of natural ventilation showed a decreasing trend towards the higher income level and preference for air conditioning. In contrast, the frequency of use of natural ventilation tended to increase as households considered it more positively. Moreover, participants who preferred to use natural ventilation at home expressed less dissatisfaction with the oscillation and unpredictability of the breeze from natural ventilation. The survey outcomes highlight the benefits of a favourable scenario for natural ventilation at home, potentially impacting households’ preferences and routines.

Ano:

Design process for an occupant survey system to assess satisfaction with indoor environmental quality

Autores:
Luiza Castro, Renata De Vecchi, Roberto Lamberts
Evento:
Building Research & Information
Resumo:

User satisfaction surveys play a crucial role in assessing Indoor Environmental Quality (IEQ). Yet, existing databases predominantly reflect data from developed countries, limiting applicability to culturally and climatically diverse regions. This study emphasizes the relevance of evaluating IEQ satisfaction in office buildings by proposing a standardized, open-access occupant survey system (OSS) for global application. User satisfaction surveys were selected as references from literature for screening and content analysis. The proposed OSS features a two-part survey that triggers detailed questions based on reported IEQ domain-related discomfort frequency. Evaluation process to ensure survey validity incorporated feedback from experts and laypersons. Additionally, a broader application was carried out with 115 office employees. Results identified prevalent issues such as acoustic and thermal discomfort, varying between open-plan and private office layouts. Participants’ responses also showed a significant link between IEQ satisfaction and time spent at the workstation. Overall, the OSS demonstrates its potential as a cost-effective instrument to provide a comprehensive IEQ diagnostic based on occupants’ perceptions. Future iterations should integrate concurrent building measurements to enhance evaluation precision and broaden the applicability of the survey tool across diverse environmental and cultural contexts.

Ano:

How to improve the thermal performance of buildings with one simulation run? The heat exchange index applied to hot climates

Autores:
Letícia G. Eli, Ana Paula Melo, Roberto Lamberts
Evento:
Building and Environment
Resumo:

Improvements in the thermal and energy performance of buildings usually involves techniques with high computational costs, such as multi-objective optimization and parametric simulation. However, sometimes, achieving the optimal case is not desirable, though only the refinement of thermal performance. Hence, methods that enable this analysis are helpful for designers and researchers. Then, this study proposed a framework based on the Heat Exchange Index to assist thermal performance analysis of buildings. The framework consists of two phases and begins by exploring air and surface heat balance derived from the base case building simulation. This analysis is based on the Heat Exchange Index, an index developed in this work, and its result indicates the impact of each heat exchange on the thermal performance. The next phase is the improvement, where strategies are defined and implemented, and the thermal performance of the improved case is evaluated against the base case. A single-family house was modeled using EnergyPlus to demonstrate the framework application. Results showed that the Heat Exchange Index could be used to enhance the thermal performance of buildings since the strategies adopted in the base case increased its thermal autonomy and decreased thermal load.

Ano:

Seleção de bolsista 2024 CB3E - Resultado [GERAL]

Aos inscritos, agradecemos pelo interesse e por participar do processo seletivo.

Nesta publicação, divulgaremos os resultados para as vagas de Pesquisador B, C e Acadêmico.

Para as vagas de Pesquisador B, houve 7 candidatos inscritos, e todos passaram para a etapa de entrevista.

Para as vagas de Pesquisador C, houve 3 candidatos inscritos, e todos passaram para a etapa de entrevista.

Seleção de bolsista 2024 CB3E - Resultado [PESQUISADOR A]

Agradecemos pelo interesse e por participar do processo seletivo.

Nesta publicação, divulgaremos os resultados para a vaga de Pesquisador A. As demais modalidades continuam em fase de entrevista e serão divulgadas conforme o cronograma disponibilizado.

Foram sete pessoas inscritas para as vagas de Pesquisador A, e todos passaram para a etapa de entrevista. Nesta etapa, os critérios de seleção seguiram as recomendações das agências de fomento nacionais, como CAPES e CNPq. Dentre os critérios, destacamos:

Seleção de Bolsistas 2024 - CB3E

O LabEEE está realizando uma seleção de bolsistas de Graduação e Pós-graduação para atuação no Convênio ECTI ECV-001/2024! 😀

Este convênio tem como principal objetivo apoiar o desenvolvimento do programa DEO-Procel, dar suporte técnico à implementação da compulsoriedade da avaliação da conformidade de edificações quanto à eficiência energética no Brasil e o desenvolvimento de um sistema de capacitação e avaliação de profissionais certificados. 

Thermal comfort evaluation in residences with natural ventilation: an application in the Brazilian hot and humid climate

A recent approach to human thermal comfort under warm-to-hot conditions indoors includes dynamic airflows, whose mean air velocities vary in time. The dynamic airflow background is based on the features of the widely accepted natural wind, recognised as more pleasant than constant mechanical airflows. Natural wind-induced airflows may occur inside buildings if climatic and building design characteristics are favourable. Moreover, natural ventilation is a primary conditioning strategy in Brazilian residences – an optimal scenario to assess dynamic airflows.

Parceria LabEEE e INPE: Desenvolvimento de Arquivos Climáticos Futuros para Simulação Energética de Edificações

Projeto desenvolvido como uma parceria entre pesquisadores do LabEEE e do INPE para desenvolvimento de arquivos climáticos futuros para as 26 capitais estaduais brasileiras mais o Distrito Federal. Espera-se com esse projeto ampliar a disponibilidade de arquivos climáticos futuros utilizando métodos mais atualizados e computacionalmente intensivos para representar as mudanças climáticas ao longo do território nacional. 

Conheça o GT - Grupo Técnico para Eficientização de Energia em Edificações

O Grupo Técnico para Eficientização de Energia em Edificações foi criado pelo Decreto nº4.059/2001, revisado pelo Dec. nº9.864/ 2019, com a missão de assessorar tecnicamente o CGIEE - Comitê Gestor de Indicadores e Níveis de Eficiência Energética, na implementação da Lei 10.295/ 2001 (Lei de Eficiência Energética) no segmento de Edificações.

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