Study On Indoor Air Quality Of Impinging Jet Ventilation System

At recent years, Air conditioning systems become more and more popular, which lead to Salient indoor air problem. Ventilation strategy as a great impact factor on indoor air quality therefore aroused extensive attention.Indoor air quality of different ventilation strategy must be very different. Nowadays most popular ventilation strategy are mixing ventilation system, displacement ventilation system, UFAD system and so on., among which mixing ventilation is the earliest, its temperature is usually assumed to be homogeneous or well mixed, while stratification is eliminated but 1AQ is sometimes questionable. Displacement ventilation system improved a lot to IAQ compare to mixing ventilation but for its low supply velocity can hardly meet the heating request for winter therefore add additional equipments for winter which also ask more investment for air conditioning systems. UFAD system is also a newly and proved to be good system for air conditioning like displacement ventilation system but easy to form dust.Not long ago, there is a wholly new system called Impinging jet ventilation system occurred in Sweden, is claimed to have advantages from both mixing ventilation and displacement ventilation system at the same time it can provide warm air in winter at present it's an ideal way of new ventilation system. Based on the previous studies, here we use fluent software to research impinging jet ventilation compared with UFAD system under variable air volume system as well as constant air volume system. Detailed analyzed and compared indoor airflow, temperature and pollutant concentration between these two systems, meanwhile use ventilation efficiency as well as percentage of dissatisfaction factor to deep exam indoor air quality and comfort condition indoor.The results showed that when cooling load is low airflow indoor just like displacement ventilation system, while cooling load goes higher airflow turns to be like mixing ventilation system under variable air system. Emission of carbon dioxide capability of impinging jet ventilation system was less than UFAD system while benzene emission efficiency was higher. Near the outlet of impinging jet ventilation system room people will feel more uncomfortable because of draft. The higher the cooling loads, airflow in both of these two systems are more like in displacement ventilation system room under constant air volume system. The ability of exhaust carbon dioxide and benzene in both two ventilation rooms are almost the same as under variable air volume system, but draft in these two system rooms are lower, and there is no such bigdifferences.