Sates that laboratory pressure is controlled by maintaining either a pressure differential across the lab envelope or a differential flow rate between the total lab exhaust and supply flows. The current design process for pressure control does not apply the knowledge of space pressurisation dynamics, which is critical for a variable air volume lab. Presents a simple model for analysing the transient response of space pressure. States the simulated results show the importance of physical variables such as air changes per hour and the leakage characteristics of the envelope on the pressure dynamics. The other findings include influence of supply flow rate response characteristics on the pressure control performance and the significance of solving mass and energy equations to select the differential flow and pressure setpoints.

KEYWORDS: Laboratories, pressurisation, variable volume air conditioning, models, analysis, air change rate, leaking.