Study of Indoor Air Quality in a Natural Ventilation and Task-ambient Air Conditioning Room
|Course||Heating,Gas Supply, Ventilation and Air Conditioning Engineering|
|Keywords||Natural ventilation Task ambient air conditioning Computational fluid dynamics|
Task-ambient air conditioning,as a new type of air conditioning strategy,has showed remarkable advantage on many occasions compared with the traditional air conditioning systems. The use of natural and mechanical hybrid air-conditioning systems can save energy during intermediate seasons.However,few results can be found in the literature.In China,such systems have been used increasingly in the current days,but its characteristics,especially in the aspect of indoor particle dispersion,have not been evaluated and investigated comprehensively.A typical office room with task-ambient air conditioning was assumed and the indoor air quality was studied.The numerical simulation has been conducted,indoor air quality,includes the indoor air flow field,the temperature field,fine particle（with a diameter 2.5μm） dispersion and CO2 distribution,were studied by varying the outdoor temperature,the air change rate,and the locations of the window.The results indicate that pollutant concentration is obviously affected by outdoor temperature, outdoor air velocity,and the flow pattern of the task-ambient conditioning and the height of the natural vent.The higher the energy conservation differences between natural ventilation temperature and indoor temperature,the poorer the indoor air quality.The CO2 concentration increased with a decrease in the inflow rate,and with a decrease in the height of the natural ventilation inlet.Compare to the desk task-ambient air conditioning,under-floor task-ambient air conditioning has a greater removal efficiency of PM2.5 and CO2.Use natural and mechanical hybrid air-conditioning systems can save energy during intermediate seasons.