Understanding Garage Door Openers

Posted: Sep 19, 2012
Author: Doors by Nalley of Lake Norman, Inc.

Garage door openers are the small motor positioned (ideally) in the center-rear ceiling behind where the garage door sits while in the open position. Garage door openers typically use one of three systems: chain, belt or screw.

As heavy as garage doors are, it may be surprising that such a tiny machine should be expected to open and close it. The truth is garage door openers provide very little of the actual energy needed to open and close the garage door, and instead mainly control how far your garage door moves.

The most common type of garage door opener is the chain, in which a chain is attached to a motor and pulled along a sprocket. The belt system works similarly, except that a belt is used in place of a chain. The screw system is the least commonly used, tending to both be less efficient and to overheat due to increased friction.

Garage doors are mainly moved not by the garage door opener, but rather by springs attached either vertically (through the less common extension system) to the sides of the door or horizontally (through the more common torsion system) above the opening.

These springs provide the primary force which opens and closes the door. The garage door opener simply provides the initial push which allows the springs to take over and push the door, and, in fact, its main job is actually to control how far the garage door moves between the open and closed positions.

Garage door openers are operated by transmitters, either portable or located on the wall. The wall-mounted transmitters operate directly through electrical currents which flip a switch, telling the garage door opener to engage. Remote transmitters operate through radio signals, which must be programmed to a certain frequency.