GB 51251-2017 第3.4.2条
| **** | The **air volume calculation** for mechanical pressurization air supply systems in smoke-proof stairwells, independent vestibules, shared vestibules, fire elevator vestibules, etc. shall comply with the provisions of Appendix A of this standard, and shall meet the **door opening cross-sectional air velocity** requirements (0.7~1.2 m/s for stairwells, 0.5~0.8 m/s for vestibules). |