Study on the dynamic natural ventilation rates of occupied residence

¹ Beijing University of Technology, Beijing 100124, China
² Beijing Key Laboratory of Green Built Environment and Energy Efficient Technology, Beijing 100124, China
³ State Key Laboratory of Building Safety and Built Environment, China Academy of Building Research, Beijing 100029, China

^* Corresponding author: jianyiwen@bjut.edu.cn

Abstract

The residential natural ventilation rates have a significant impact on indoor thermal comfort and air quality and building energy consumption. The characteristics of the indoor-outdoor temperature difference and wind pressure change over time, as well as the occupants' window opening behavior and the use of HVAC systems, resulting in the residential air change rate being dynamic with time. Many previous studies of residential ventilation measured the steady-state air change rates, which does not reflect the actual dynamic characteristics. In this study, a field measurement was conducted in a bedroom of one natural ventilation residential building in Beijing with continuously monitoring the CO₂ concentration, indoor air temperature, and outdoor meteorological parameters for one year. Using the CO₂ released by occupants as a tracer gas, the extended Kalman filter based on the Transient Mass Balance Equation (TMBE) was adopted to calculate the dynamic air change rate. This method can effectively filter the CO₂ concentration measurement noise. The trend of air change rate with each influencing factor was analyzed. This study is expected to lay the foundation for future studies of dynamic air change rates in residential buildings.