Fire doors are generally classified into two types: normally closed and normally open.
Normally closed fire doors should be kept closed at all times and should not be intentionally opened or locked. These doors are typically installed in less crowded areas, such as stairwells and fire escape routes. They should remain closed under normal circumstances and during a fire to effectively slow the spread of fire and smoke.
Normally open fire doors are generally installed in areas with high foot traffic, such as schools, large shopping malls, and hospitals. They are normally kept open for easy passage, but in the event of a fire, they automatically close via fire door monitoring systems and electric door closers to provide smoke and fire protection.
