Door closers as we know them have been around for well over 100 years. Originally invented as crude mechanisms simply to ensure that doors closed to prevent draughts and contain heat within rooms and buildings, modern engineering has turned these into highly sophisticated devices.
Doors form part of the fire integrity of a building, and both fire safety and security requirements now mean they must reliably close and be kept closed to contain and delay the spread of fire and smoke; giving individuals time to escape or for emergency services to arrive.
There are numerous types of standard closers, including overhead, floor mounted, transom mounted and concealed, either within the jamb or inside the top rail.
Some closers have fixed closing strength while others are adjustable, but the correct power size should always be selected depending on the width of the door.
According to recent disability legislation, consideration must also be given to the ease (or difficulty) for infirm, less abled ambulant or wheelchair-bound people in opening the door against the closing strength of the closer. This means that modern closers must be efficient and be easy to open, yet at the same time still be reliable in closing the door.
Aesthetics are also an important part of today’s design, and whereas door closers historically were bulky and possibly even noisy, modern closers can have minimal impact on the appearance of a door, matching in with other ironmongery, such as a lever or pull handles. The mechanisms usually have slimline covers, and also the traditional projecting angle arms in a lot of cases have been replaced by sliding arms and channels. These can all be finished in complementary colours or metallic finishes to match any particular theme or style.
If the design demands it, a closer can be hidden within the door, either in the heel of the door which is completely concealed when the door is closed, or morticed into the top rail with a slide arm and channel. Floor springs, which are mounted in the floor, can be used for particularly heavy or large doors, and also provide a method for a door to open and close in both directions.
Door closers are also available to hold a door open (e.g. for corridors) and close automatically when the fire alarm is activated. These are standard closers with an integral powered electromagnet which is deactivated by means of a relay linked into the alarm system. These closers allow unobstructed passage but at the same time maintain fire integrity.
Another variation of this is a ‘free-swing’ closer, which incorporates the same electromagnet linked into the fire alarm, but an ingenious cam arrangement within the arm allows the door to be operated as if it had no closer attached, a boon especially for the elderly in care homes.
This article is courtesy of Bruce Ching at A C Leigh.