Researching And Analysis Of Indoor Air Quality In Office Buildings In Xi’an

As the development of economy and increasing of people’s living standard, the requirement of a good and comfortable indoor environment increases urgently. Faster rhythm of life and greater working pressure make people work in offices for longer time. The quality of indoor air environment in offices affects not only people’s working efficiency, but also people’s health. The emergence and development of air conditioning system means an effective method to control indoor air environment which is different from natural ventilation. But air conditioning sickness and quickly increasingly building energy consumption resulting from air conditioning system have become a problem that can not be ignored.In order to get relevant test data which can reflect the overall indoor air environment and enrich the underlying database of indoor environment in office buildings in Xi’an, the indoor air environment of two typical office buildings in Xi’an is measured couple with questionnaires and the results are analyzed deeply.By researching and analyzing, it discovered that the temperatures, humidities, velocities in two office buildings all meet the design demand of amenity conditioner and the energy conservation demand. Meanwhile, the concentrations of CO₂,formaldehyde and TVOC also all meet the design demand of <Indoor Air Quality Standard>（GB/T18883-2002）.Air conditioning system makes the indoor air temperature different from the setting temperature, which means that there is more possibility for a better designing and using method. The air supply mode with air diffuser benefits the ubnformity of indoor air temperature compared with mode with fan coil. There is obvious difference between the air temperature evalutions of transitional season and summer. The most comfortable indoor air temperature for indoor workers is under 26.4℃, and the comport decreases with the increasing of air indoor air temperature. The change width of indoor humidity in offices is larger than that in transitional season. The humidity in offices in transitional season is relatively low, so humidification measures such as indoor air humidifier should be taken. The most comfortable indoor air humidity for indoor workers is 45.2% in transitional season, and is 55% in summer. The demand of indoor air velocity to meet the comfort demand of people work in offices in summer is larger than that in transitional season. Fresh air system can bring higher comfort to indoor workers without increasing indoor air velocity, and the best indoor air velocity is 0.17 m/s.Air conditioning in summer was more conducive to the diffusion of chemical pollutants than natural ventilation in transitional season and helped to avoid the concentration of chemical pollutants. Air conditioning in summer does better than natural ventilation in transitional season in improving indoor air quality.The degree of pollution of chemical pollutants in transitional season was more serious than that in summer., but acceptance of indoor air environment in both summer and transitional season is relatively high. The main pollutants of indoor air are TVOC and CO₂ in transitional season and is CO₂ in summer.The indoor air temperature, humidity, velocity and indoor air quality affect people’s feeling most serious in both summer and transitional season. The effect of noise on people in offices can not be ignored.