Air tightness measurement with transient methods using sudden expansion from a compressed chamber

Air tightness in an escape route of a building is important in preventing a fatal disaster by smoke spreading during a fire. To measure air tightness, transient methods using sudden air expansion from a small compressed air chamber into a room are proposed. Pressure variations in the chamber and the room are measured, and effective leakage areas are evaluated using differential and integral transient methods. The results of the two transient methods are compared with results from a typical steady method using an external blower fan. As a result, it was confirmed that all three experimental methods show good linearity between the imposed open hole area and the estimated effective leakage area. Therefore, the effective leakage area estimated using the transient methods could be converted to the equivalent leakage area of the steady method. The transient methods proposed in this study are expected to be more conveniently adopted for measuring air tightness if a suitable conversion factor is preliminarily evaluated.