Building Hardware Resource

A door closer is a mechanical device that closes a door, in general after someone opens it, which is called manual door closer, or after it is automatically opened, that’s an automatic door closer. Door closers are mainly used in commercial and public buildings in case of fire situations, or resistance to opening forces (for use by disabled or infirm) as well as health, safety, durability, risk of vandalism/ligature and aesthetics, but they may also be used around the home where circumstances make their use desirable.

There are different strengths of overhead door closer. They are manufactured with either different or adjustable strengths to cater for the size and weight variation of different doors. The bigger and heavier the door, the greater the force required to close it. This force is usually designated by assigning the closer with a number value between 1 and 7 where the higher the number indicates a larger capacity of closer.

If a door closer is being fitted to a fire door, then it is usually recommended that a minimum of a size 3 is fitted. Air pressure on the door from wind is also a consideration which could lead to a higher size number than the actual door weight being needed. Restrictions in the design of certain buildings may lead to arrangements where special brackets are needed to mount the door closer. The use of these brackets can often weaken the strength of a closer and require that a size higher than that needed for the weight of the door is necessary. Some types of door closers can vary their strength number by altering the position of the closer on the door by means of moving it along a bracket. This is convenient where the size required is uncertain and facilitates a greater range of adjustment at the time of fitting. Typically these closers can be designated 2-4 size or even 2-6 size in certain circumstances.

Not all overhead door closers are fitted to the door in the same way. It is generally dictated by the door arrangement the closer is to be fitted to. Three most popular applications are called ‘figure 1′, ‘figure 66′, ‘figure 61′ respectively. ‘Figure 1′ is where the closer is fitted to the opening face of the door on the hinge side, while ‘figure 66′ is where the closer is fitted to the closing face of the door opposite the hinge side, and ‘figure 61′ is used where the closer body is inverted and fitted to the head frame rather than the door itself. ‘Figure 61’ is a further application which can also be used on outward opening external doors, particularly those where the door only has a narrow top rail, not wide enough to house the body of the closer.

Someone may don’t want the door closer to be seen. There are door closers available that can be concealed into the top of the door. Although this is a great way of ‘hiding’ the closer, a large part of the door must be cut away to house the body and this will reduce the fire integrity of the door. It is always a good idea to check with the fire prevention officer that this type of door control is suitable. There is also a type of closer that will fit in the side of the door with the mechanism contained inside the door. You may find one on market.