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Naturally ventilated buildings' performance relies on their design and climatic conditions. Thus, when investigating the natural ventilation potential (NVP), the meteorological data plays a crucial role. This study discusses NVP assessment under two approaches: a general evaluation, using only meteorological data; and a specific investigation through building simulation. Both analyses included in-situ measured data and open-access weather file. When compared, the climatic data presented some differences in the frequency of wind direction/speed values. Still, they showed similarities in the hourly data, which were perceived in the NVP general analysis. A multi-zone Airflow Network model was employed for specific NVP examinations. Following a structured calibration process, using measured data from an experimental campaign, the validated model presented a final total Goodness-of-fit (GOF) of 2.98%. Subsequently, an annual building simulation was carried out with a hybrid operation mode. The number of occupied hours with natural ventilation and heating loads presented the most significant difference to the detriment of the weather file used, depending on the zone. A greater discrepancy in thermal comfort evaluation was perceived according to the adaptive standard employed. The paper discusses some challenges faced at the NVP analyses and the calibration process, ending with some suggestions on how to address these issues.

Climatic zoning is frequently used in building energy efficiency regulations. However, there is no consensus about which climatic zoning method should be used for a given purpose. This study aims to verify if building performance data is necessary to propose a climatic zoning for building energy efficiency regulations. First, an exploratory data analysis was performed based on correlations of climatic variables and building performance results from an office building in 411 Brazilian cities. The same building performance results were used to perform a preliminary assessment of seven climatic zoning methods: two globally well-known methods (ASHRAE 169 and Koppen-Geiger), the current Brazilian regulation method (NBR 15220), a proposal for a new Brazilian regulation (Roriz) and three alternative methods for climatic zoning proposed by the authors. The alternative methods were named as Data-driven, Enhanced degree-day and Decision tree method. The final assessment included 21 variations in the office building. The performance of each climatic zoning method was analysed according to two indicators: uniqueness and dispersion. This study shows the importance of building performance data to improve the quality of climatic zonings for building energy efficiency regulations.

Este estudo tem por objetivo investigar a incerteza do método de simulação da NBR 15575-1 (ABNT, 2013) nos resultados dos níveis de classificação de desempenho térmico de habitações. A investigação compreendeu análise do desempenho térmico de uma habitação por simulação computacional no programa EnergyPlus, para o clima de Florianópolis - SC. Foram analisadas variáveis imprescindíveis para a definição de um dia típico, as quais são desconsideradas pelo método de simulação da norma, como data do dia típico de verão e inverno, velocidade e direção do vento, algoritmo de cálculo da irradiação solar e tipo de céu. Tais variáveis foram utilizadas em projeto de experimento estatístico com combinação fatorial para determinar a incerteza nos resultados e a sensibilidade das variáveis no nível de classificação de desempenho. As simulações foram realizadas com nove modelos diferentes de envelope da habitação. Os resultados mostraram que os piores níveis de classificação de desempenho, tanto no verão quanto no inverno, foram os modelos sem contato com o solo. A variável de maior influência para a análise no verão e inverno, para todos os modelos de envelope analisados, foi o tipo de céu. Pode-se concluir que as variáveis desconsideradas pela NBR 15575-1 (ABNT, 2013) na criação de um dia típico para simulação exercem considerável influência nos resultados dos níveis de classificação do desempenho térmico, gerando imprecisão nos resultados. This study aims to assess the uncertainty of the NBR 15575-1 (ABNT, 2013) simulation method regarding the results of the thermal performance rating levels of a dwelling. The assessment was performed by analysing the thermal performance of one dwelling using the EnergyPlus computer programme, for the climate of Florianópolis-SC, Brazil. Essential variables, which are not considered in the standard's simulation method, were analysed for the definition of a typical day, such as the date of the typical summer- and typical winter-day, wind speed and direction, solar irradiation calculation algorithm and sky clearness. These variables were used in a statistical experiment with factorial combination to determine the uncertainty of the results and the sensitivity of the variables for rating thermal performance levels. Simulations were carried out for nine different building envelope models. The results showed that the worst performance levels, both in summer and winter, were obtained for those models without ground contact. The most influential variable for summer and winter analyses, in all cases, was sky clearness. Based on these results, theconclusion was made that the variables ignored by NBR 15575-1 have considerable influence on the thermal performance rating levels of buildings, resulting in the lack of accuracy of the final results.