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of a conventional office building in the city of Rio de Janeiro and two groups of design parameters, dynamic thermal simulations are systematically applied to optimise design options with the aim to maximize the annual acceptable thermal comfort levels within the occupied spaces. This study not only defines the dimensional parameters to maximise the system airflows, but also investigates the significance of design decisions such as thermal mass and shading devices on the system performance. Options to avoid unintentional reverse flow on the upper floors and maintenance of balanced horizontal airflow rates across the floors are also addressed.Two optimized naturally ventilated building models with DSF are developed and evaluated in terms of thermal performance. Results show that acceptable thermal comfort levels can be met for nearly 70% of the occupied hours. Although the office building will still require other means of cooling during peak summer periods, the incorporation of DSF as part of a mixed-mode ventilation strategy can potentially have a significant impact on annual energy consumption. Highlights Optimised DSF models demonstrate acceptable thermal comfort levels for nearly 70% of the occupied hours  Shading device characteristics are the most influential parameter on the thermal performance of DSF  Extending the cavity height by one and a half floors above the roof avoids reverse airflows on the upper floors  Similar airflows on all floors can be achieved by optimizing the free area of window openings

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This study has predicted the annual thermal acceptance levels in naturally ventilated office buildings with double skin façade (DSF) under different Brazilian regional climates. It builds upon the outcomes of a comprehensive research programme on the study of generic thermal performance of naturally ventilated office buildings with DSF, which has identified and evaluated the key design parameters affecting the thermal behaviour of DSF through computational simulation models. Taking into account Brazil's bioclimatic zones characteristics, including the solar incidence and wind conditions, design configurations are adapted, optimised and embedded within computational models for analysis. Thermal acceptance levels of each region, using operative temperatures as the thermal comfort index, are illustrated. The highest levels of thermal acceptance, as high as 90%, are experienced in the south and southeast regions. Around 65% can be achieved in regions of centre-west, north-west and coastal areas, but only 20% in the arid region of the north-east.Significance of these thermal acceptance levels is discussed and comparisons to single skin façade (SSF) models highlight the benefits and constraints of the application of the DSF.The methodology and the results developed from this study enable initial assessment of application of DSF in naturally ventilated buildings under warm and hot climates.