Research Of Indoor Environment Affected By Opening Door And Windowinthe Condition Of Natural Ventilation

As a traditional and ancient way of ventilation, natural ventilation nowhas receivedincreasingly attention on the occasion of the energy is becoming scarce. To adjust theindoor temperature and humidity, improve building thermal environment; to reduceharmful gas generated and microorganisms and to introduce outdoor fresh air; to reducethe building energy consumption by making an appropriate choice of ventilationstrategies, can all be achieved by opening doors and windows in a proper way andorganizing the air flow. Therefore, it is necessary to research the impact of naturalventilation on indooe environment.To change the open degree of doors and windows can change the dragcharacteristic of the openings, which changes the indoor ventilation rate, temperature,humidity and pollutant concentration. The experiment platform had been set up inBaisha town in Chongqing, and it is in an energy conservation demonstration building.By using CO2as the tracer gas, and using the doors and windows at a specific opendegree as the method of changing the ventilation rate, the experiment studied thechangeofconcentration of the CO2at the condition of various open degree of door andwindow, and also，the change of temperature and humidity are taken into considerationof the investigation.In the study on drag force characteristics of door and window, the CFD softwareAirpak had been used to fullfil the simulated ananlysis. The testing runs six kinds ofopen degree of each opening, so that there are36working conditions altogether to studythe ventilation rate. The relation between the open degree and the discharge coefficientof the side hung door and sliding window each had been fitting out by using the leastsquares method. And so did the relation of door and window together. Afterfitting outthe flow coefficient, the result of the calculation and experiment data of outdooratmosphere had been used to calculate the ventilation rate in various opening degrees ofthe door and window by the software of CONTAMW, which based on the multi-zoneairflow network modeling. At last, the indoor environment had been studied in thecondition of different ventilationrate, and the variation trend of CO2concentration,temperature and humidity had been found out.Conbining the researching method of measure and simulation, the aiticleanalysised the dragcharacteristic of door and window, and the influence of the indoor environment on various open degree of door and window. The conclusion had beendrawn as follows：①To change either of the side hung door or the sliding window can affect theventilation condition in a room. Under the influence of both side hung door and slidingwindow, the effect of the window is larger.The relation between the open degree and thedischarge coefficient of side hung door and sliding window can be described by thelinear function approximation. The way of flow coefficient calculation of multipleopening modeling should be modified by concerning the extent of the impact of eachopening.②In the condition of natural ventilation, the indoor attenuation trend of pollutantconcentration turned out to be concerned with the following facters: the ventilation rate,the velocity of pollutant release, the difference value of concentration between indoor’sand outdoor’s. And the velocity of temperature changing is also concerned with theradiation of cooling and heating source, the ventilation rate and the difference intemperature of indoor and outdoor.③The indoor environment will change in the process of open doors and windows.It is found that within the same time, the concentration of indoor pollutants attenuationrate appears bigger, while the change rate of temperature and humidity shows smaller. Ithad been proved that it is possible to improve indoor air quality while reduce the loss ofcooling by open doors and windows in summer.