While it is advisable to seek professional help for fixing the broken spring mechanism, one still has to choose the particular spring type to replace the broken one with. This is very important, because the right choice would have prevented the breakdown to begin with. There are two popular ones available in the market: the torsion-type spring and the extension-type spring. But which is better? To find out, we must first understand what each type is, and how they work.
In most cases, helical-shaped metal rods or wires are used to build torsion springs. They are so arranged, that external forces when applied, twist the coils tighter about the spring's axis.
One end of the spring is attached to a stationary cone, while the other one is fixed to a rotating, winding cone, using nuts and bolts. When the garage door is raised, the winding cone rotates and the spring uncoils due to the stored tension, and the force thus created rotates the shaft. This in turn rotates the cable drums, wrapping the cable and lifting the door. When the door is lowered, the cables unwrap, and the springs are wound into tension again.
2) Smoother Operation: Extension springs can vary in tension during the door's operation. For example, when opening the garage door, there may be a larger amount of tension initially which ebbs away towards the end. This causes a jerky motion while opening or closing the door. A torsion spring, on the other hand, offers a much more smoother range of motion to the door.
3) Easier Maintenance: The extension spring arrangement on a garage door requires more number of parts, including longer cables, pulley arrangement, hooks, and metal tracks. This increases maintenance requirements and also the chances of failure of the system. The torsion spring based mechanism requires significantly lesser number of parts, and thus, maintenance is easier with lesser chances of failure.
4) More Efficient: Due to the jerky behavior of the extension spring, the motorized garage opener may have to draw larger power to open the door. Conversely, the much more balanced behavior of torsion spring prevents the loading of the opener's motor, and thus saves on power, making it more energy efficient in comparison.
5) Safer: An extension spring, when stretched, is in a very dangerous position. It stores a lot of energy, and in case the hooks and holders holding the spring break, it can cause serious damage. There have been incidences where the extension spring mechanism in garage doors have broken, causing the springs to fly off and damage the windows, car windows, windshields, etc. In the worst case, the flying springs can severely injure a person, even leading to death. Thus, it becomes essential to use some kind of protective countermeasure to ensure safety while using this mechanism. Comparatively, a torsion spring is retained in the shaft in case of a breakdown, making it completely safe to use.
Thus, it is clear that torsion springs are a better choice for garage doors. They may be costlier, but are much safer and give a better pay-off in the long run. Only in rare cases, when factors such as limited head-room in the garage prevent the installation of torsion springs, should one go in for extension springs. In such cases, for safety reasons, one must carry out regular maintenance of the mechanism.