Belimo came with a new actuator (Belimo AFBUP) which has same torque rating as the previous AF-24 and AF-120. This would works across 24V to 240V AC or DC power supply. This takes away any error in ordering, and specifying. This is a universal actuator which shall meet most HVAC systems needs. It has power running time of 75 seconds and spring operation time of leas than 20 seconds. For faster acting application, we need to look at other actuators.
Commercial and residential buildings pressurization calculations
Building pressurization calculations has long been one of the unknowns to most HVAC professionals. We have always wondered how much air we need to pressure a building. NFPA and ASHRAE have publications which define this based on building type, number of doors/windows, construction type, etc. We have created a simple spread sheet which makes it easy to accomplish this task. This goes together with door closure forces calculations. Some buildings in toxic chemical industry environments have to be pressurized to higher pressure to prevent infiltration of toxic gases during blasts. Door closure forces has to be adjusted to account for this. There are several other considerations especially w.r.t. ceiling, door undercut, pressurization air distribution, etc. Contact me for further information and details.