I've run into a small access control issue and would be curious about solutions. At a site we are building there is a designated "Tornado Refuge" room, which must allow entry (much like a fire exit). The problem is that the room is also a secondary server room (don't ask - I didn't design it ...) and therefore I need to keep it secure. Door opens inward to the room. One option is a panic bar with a delay, much like, again, a fire exit door might be programmed. Client isn't fussy about that. They also say that for various reasons they cannot put a lever on it that would simply unlock when required by condition. Any other cool ideas? Worst case is just go ahead and leave it unlocked, but create an alarm and video record/response each time.
JS