Window Opening Behaviors In Naturally Ventilated Hospital Wards And Its Influence On Ventilation Performance

Natural ventilation is recommended to be used in general hospital wards by the World Health Organization?WHO?,and is stipulated to be used in outpatient departments in China GB 51039-2014.Central corridor type is one of the most common design for general hospitals in China.This paper aims at studying window opening behaviors and its influence on ventilation performance in naturally ventilated wards with central corridor type based on field measurement,statistical analysis and numerical calculation.A long-term field measurement was conducted in 2 general hospital wards in Nanjing,China.The effects of air quality(i.e.indoor CO₂ concentration and outdoor PM_2.5 concentration)and the climatic parameters?i.e.indoor/outdoor temperature,relative humidity,and outdoor wind speed,wind direction and rainfall?on window opening/closing behaviors are analyzed in logistic regression model.Based on the seasonal variation of window opening behaviors,logistic regression models in different seasons?cooling,transition and heating seasons?are thus developed and verified to be promisingly adaptable with a result of accuracy higher than70%.The influence of wind profile on the natural ventilation rate calcualtion is analyzed.It is found that the wind profile is one of the main driving forces for single-sided ventilation,especially in low Ar number.The influence of wind profile on cross ventilation is less significant than that on single-sided ventilation.Annual venlitation rate in the measured hospital wards is calculated based on natural ventilation prediction models and tracer gas method.Results turn out that natural ventilation can provide high ventilation rate(up to 34.8 h^-1)during the measurement.However,the inner doors connected with the corridor act as the main air inlet,while the outer windows act as the main air outlet.This may lead to cross-contamination between wards.