The droplet aerosol generated by human expiratory (breath, cough, sneezing) is a major indoor biological pollutant and can lead to allergy, asthma, infectious disease and so on. The transmission of the droplet aerosol has a hugely influence on the health of occupants. This paper summarized the distribution and transmission of droplet aerosol generated by human expiratory, reviewed the factors which influenced the air transmission and the model of transmission of the investigated droplet aerosol. In addition, the current problem and future research about the human expiratory droplet aerosol in indoor environment were discussed in the paper.

Indoor environment of VAV system was paid more increasing attention, besides the energy saving, zone temperature control of VAV system. In this paper, using in-site testing and analysis, some experiments were conducted on indoor environment of the typical office with self-regulating inlet VAV system. The results showed the temperature and relative humidity of the selected office were in the range of 22.8 °C~24.5°C and 27.0%~35.0%, respectively. The maximum volume of total supply airflow is 816 m3/h, while the minimum one is 557 m3/h. The concentration of carbon dioxide ranged from 0.0596% to 0.0873% (v/v). The calculated maximum value of temperature uniformity coefficient was 0.026 that indicated the distribution of indoor air is uniformity. So this VAV system used in the office building provided a good indoor environment to meet the satisfaction of the office staff.