Influence of design parameters on the night ventilation performance in office buildings based on sensitivity analysis

Overheating and energy-extensive consumption in buildings, especially in office buildings, are emerging challenges. Night ventilation (NV) is a promising technique. The performance of NV can be evaluated by a series of performance indicators. As many design parameters affect those indicators, it is beneficial to choose suitable indicators and identify the most important design parameters to develop more efficient design solutions at the early design stage. Sensitivity analysis makes it possible to identify the most important design parameters in relation to NV performance and to focus design and optimization of NV on these fewer, but most important, parameters. A holistic approach integrating sensitivity analysis and parametric simulation analysis is developed to explore the key design parameters on night cooling performance indicators and evaluate the applicability and limitations of those indicators. The results show that the climatic conditions and NV modes strongly affect the influence of design parameters on the performance indicators. The window-wall ratio, internal thermal mass level, internal convective heat transfer coefficient, and night mechanical air change rate are the most important design parameters. The indicators of ventilative cooling advantage, cooling requirement reduction, and percentage outside the range are recommended for the night cooling performance evaluation.