A Pivoted Window Capable Of Stabilizing Ventilation Rate Automatically

Natural ventilation is an economical means to improve indoor air quality,and can remove out pollutants and excess heat,which is beneficial to the physical and mental health of the occupants.Wind pressure is the primary driving force for natural ventilation through windows,while the fluctuation of natural wind makes the ventilation rate vary greatly.Excessive ventilation in the event of strong winds can cause unnecessary energy consumption of heating or cooling if windows are opened for ventilation.The uncontrolled natural ventilation may also cause discomfort and affect people’s normal activities.Mechanical ventilation equipment or fully automatic electric windows can be used to control ventilation,but would require higher energy consumption and cost.There is still a lack of such a form of window that can improve the controllability of natural ventilation just through simple and reliable structure,and should be economical and suitable for widespread use in five climate zones in China.This thesis proposed a horizontally pivoted window that can adjust the opening size automatically,and the opening angle of the window sash is regulated by the compromising action of the wind-driven pressure and the gravity.Neither senor nor electric actuating mechanism is required.Taking into account the different needs of the occupants,the proposed window was designed with different openable ranges which can be adjusted according to demands.The structure of each component of the pivoted window（mainly including the shaft accessory and sash restraint unit）were designed according to the required functions.A window prototype was built and installed onto the south wall of a test room located on the roof of a certain building,and its resistance characteristics while rotating and short-term and long-term ventilation rates of the test room when the pivoted window was opened were tested.A simulation strategy for adjusting the opening angle of the pivoted window was proposed,and the accuracy of the simulation of EnergyPlus was verified by experimental tests.The last step was to build the model of a typical house in EnergyPlus,and the effectiveness of the ventilation rates,indoor air quality and energy consumption of the typical house applying the pivoted window in five representative cities were calculated,and were compared with the results of the house applying the ordinary window.The research results show that,the designed pivoted window can effectively avoid the situation of excessive indoor ventilation through adjusting the opening angle of the sash under instantaneous high wind speed,and can maintain indoor ventilation into a relative stabile level.Simulation results were consistent with the experimental results of ventilation rates,CO₂concentration,temperature and air-conditioning energy consumption of the test room.According to the simulation results of the two house in different climate zones that use the pivoted window and ordinary window,compared with the ordinary window,the pivoted window can keep ventilation rates more stable,and can reduce the over-standard rates of CO2more effectively,while require less energy for cooling and heating in most cities at the same time.Applicating the proposed pivoted window can create better indoor air quality without the immoderately high cost of energy consumption.