Air infiltration rate of typical zones of public buildings under natural conditions.

• The airtightness of three typical zones of public buildings was tested. • Their air infiltration rates for 1800 cases were simulated. • The influence of air infiltration on public buildings was analyzed. Air infiltration of the building is closely related to its indoor thermal environment, indoor air quality and energy consumption. It is known that, there have been only a few studies focusing on the prediction of air infiltration rate in public buildings in the cold area of China. In this paper, the airtightness of three typical zones of public buildings was tested and their air infiltration rates for 1800 cases were simulated based on the test results. Field tests show that the air change rates under the pressure difference of 50 Pa of the three zones are 3.8 h⁻¹, 4.4 h^-1, and 5.2 h⁻¹, respectively. The airtightness of the zones built later (2007) is even worse than that built much earlier (1990). Simulations show that the air infiltration rate ranges from 0.01 h⁻¹ to 0.23 h⁻¹ with an average of 0.09 h⁻¹ for zone 1, from 0.03 h⁻¹ to 0.87 h⁻¹ with an average of 0.37 h⁻¹ for zone 2, and from 0.05 h⁻¹ to 1.05 h⁻¹ with an average of 0.50 h⁻¹ for zone 3, respectively. The frequency of the AIR of all the three zones presents a logarithmic normal distribution. Discussion shows that the impact of air infiltration on public buildings should be fully considered when designing the HVAC system. [ABSTRACT FROM AUTHOR]