Q and A Banners

Q and A Banner - #3 (World Records-1)

Thursday, December 29, 2011

0 WHY DO MOST PUBLIC DOORS OPEN OUTWARD AND HOUSE DOORS INWARD?



For Security and Safety

A great deal of you may already know the answer to this question - a great deal of you may not, but I've never really thought about it until friends from abroad would visit us here in Canada and they would always have a tendency to 'push' instead of 'pull' the doors whenever we entered restaurants and other public places.
Here in North America, there are perfectly good reasons why the doors open the way they do.


House Doors (Inward Opening)

Beside the fact that you don't want to strike your guests or visitors in their faces when opening the front door of your home, lol, or possibly knocking them down the stairs (if you have stairs leading up to your door), inward-opening of house doors has its reasonings behind it.

House doors are built opening inwards for reasons such as easier to install, easier to repair and even easier to build!  It's also easier to disassemble by removing the hinge pins which detaches the door completely from the frame, thereby making it much easier to squeeze in that oversize couch you just bought! 

While this may be easier on you as a homeowner, it's not something you want easier on possible intruders, so, for this reason, the hinge mechanism needs to be positioned inside the house - making it the natural way for the door opening to be inwards.




Public Doors (Outward Opening)

Because of such tragedies such as the Cocoanut Grove fire of 1942:


".. other unlocked doors, like the ones in the Broadway Lounge, opened inwards, rendering them useless against the crush of people trying to escape. Fire officials later testified that, had the doors swung outwards, at least 300 lives could have been spared...."
laws were enacted and enforced for public places in regards to the opening direction of, not only main entrances, but exit doors as well.

Unlike a private home, a public building usually contains a larger amount of people.   In the case of a fire or other emergency, these people need to be able to escape or be evacuated as quickly as possible. When a panic-stricken crowd of people rushes an exit, it’s very hard for somebody to open the door inward. Everyone pushes up against the door, and there’s no room for it to open. Therefore an effective emergency door has to open outward, moving with the force of the crowd. 
Wide Panic bar or Crash bar on door
 
This is also why a lot of emergency exits are built with wide panic bars instead of ordinary door knobs. The basic idea is to build the exit so even the most out of control crowd will be able to escape.

The idea was first put into practice after the events of the Victoria Hall disaster in Sunderland, England in 1883.  It saw widespread use after the Iroquois Theater Fire in Chicago, USA, which killed 602 people on December 30, 1903, and the Italian Hall Disaster on Christmas Eve 1913.

To maintain perimeter security, public exits are typically build with concealed or protected hinges, which are much harder to detach than a simple pin hinge. These doors are more expensive to install and repair, making them impractical for anybody’s normal house. And as long as you don’t have an unruly mob living with you, these outward opening doors don’t offer any real advantage in your home.

There’s another reason for outside doors as well. Any public building that contains a lot of people is normally required to pump in extra outside air to keep oxygen levels high and carbon dioxide levels low. This air is just brought in from the outside through the heating and air conditioning system. This usually over-pressurizes large buildings, so if you had an inward opening door, that over-pressurization would tend to push the door shut and make it really hard to open. With an outward opening door, it’s much easier to get the door open against that over-pressurization. The air pressure works with you to open the door.


So which way do doors open in YOUR country? 


Source(s):  howstuffworks.com/, wikipedia,






No comments:

Post a Comment

Thanks for leaving a comment - it is welcomed!☺