I am designing a smoke extract system for a big atrium within an office building. The atrium is about 12 floors height and with skylight. Smoke extract fans shall be installed at the highest point of the atrium, which will work as a heat relief as well because this project is in a very hot country. The fans shall be double speed as the smoke extract rate will be huge, while the heat relief extract flow will not be high. The question is: Do I have to install a makeup fan for the smoke extract? Does the smoke extract in general require makeup air or not?
