I happen to have experience with one of these types of doors at a company I worked at. It was only the main door. You couldn't put them on all the doors because if you did and the power went out you'd be locked in the building. I was most impressed with how impossible it was to open the door when it was locked down. I'm 6 feet tall and at the time like 250 lbs. It didn't budge one inch.
Being curious I asked how it worked etc. I guess some people do make them the other way but it doesn't seem very useful if cutting the power takes it out. Not to mention wouldn't holding the door closed with constant electricity waste a crap-ton of money?
I happen to have experience with one of these types of doors at a company I worked at. It was only the main door. You couldn't put them on all the doors because if you did and the power went out you'd be locked in the building. I was most impressed with how impossible it was to open the door when it was locked down. I'm 6 feet tall and at the time like 250 lbs. It didn't budge one inch.
Being curious I asked how it worked etc. I guess some people do make them the other way but it doesn't seem very useful if cutting the power takes it out. Not to mention wouldn't holding the door closed with constant electricity waste a crap-ton of money?