A door closer is a mechanical device that shuts a door after it has been manually opened. A door closer may be required for many reasons; these are addressed below.
All fire-resisting doors should be fitted with an automatic self-closing device. Closers should be capable of shutting the door from any angle and against any latch fitted to the door. For security reasons, if you have any kind of access control, you need to ensure that the door will always close.
Closer functions sometimes contribute to the protection of the door, other door hardware and the adjacent fabric of a building. As well as protecting the door you will also want to protect everything in the room. A door closer will prevent heat (or cold) loss or draughts in a building to protect sensitive equipment in environmentally stable rooms and clean rooms.
Sometimes, for a variety of reasons, you just want a door to close.