Pressurization smoke control systems, which mechanically supply air to shafts such as elevator shafts, are based on the assumption that initial temperature difference between inside and outside of a shaft is maintained even after the pressurization has operated. However, low temperature air supplied from the outside may gradually lower the inside temperature so the difference of temperature and hence of pressure maybe made smaller. In this study, a model experiment of pressurization of shaft was conducted to investigate the effects of rate of air supply, opening area at the top of a shaft, difference of air supply mode, on the temperature and pressure difference. Also, an analytical formula was developed to estimate the temperature and pressure difference. A fair agreement was obtained between the predictions by analytical formula and experimental measurements.
