Lift lobby/well pressurization Lift lobby/well pressurization HVAC68 (Mechanical) (OP) 9 Nov 06 02:28 What's the air changes to be considered for pressurization of(a) Lift well(b) Lift lobby HVAC68 RE: Lift lobby/well pressurization atlas06 (Mechanical) 30 Nov 06 23:44 By lift well, I guess you mean elevator shaft.This pressurization business comes into play only for buildings requiring smoke evacuation systems.In the US, we simply don't pressurize elevator shafts. Unfortunately, life safety is one the vaguest areas in our industry in the US, there is so much liability (we have 60% of the world's lawyers) that the codes keep being revised with more and more "engineered systems" being called for by the code. There is not one code that will say pressurize or not pressurize elevator shafts (including ASHRAE).The problem with elevator shafts is that here we require them to have a relief opening at the floor below the top floor. So pressurizing the elevator shaft is just not practical, we do use elevator lobby pressurization at o.5" static pressure when required such as pressure sandwitch in smoke control in jails and the likes.If I were to pressurize, I will make sure that the system serving the lobby is a dedicated system and all other adjacent areas go into negative in a smoke control mode, this will keep the smoke from migrating from one floor to another through the elevator shaft.why do you want to pressurize anyway? is your application a smoke control issue? or just comfort? Your air balance for your entire ebuilding should see a 5% to 10% positive pressure overall anyway.Not much help from this side of the Atlantic on this one I am afraid.