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As we inch closer to March 20 tomorrow, the first official day of spring in the U.S., there’s a hint of spring in the air after a dreary winter season. We can see new growth starting in our backyards. There’s a freshness and a stillness to the outside world, one that’s been allowing a few 60°F days to shine through in parts of the northeastern United States. Even in parts of the country where weather isn’t as intense, we’re all ready for a change of seasons, and with it, a change in perspective.
Because we’re all ready to spring forward to the new season, we thought it would be great timing to cover one of the most asked-about topics in rolling doors: you guessed it…springs! (We won’t apologize for the pun.)
Rolling security doors come in two options in regards to springs: with springs and without (also called springless). Let’s review the basics.
How do rolling doors with springs work?
Rolling security doors have springs to help lift them, especially since large doors can be really heavy, exceeding 800 pounds or more. The springs are located inside the barrel in the headroom. They work by using a counterbalance spring system, where the spring is wound from one side to tighten it inside the barrel. As the door is lifted by a person or operator, the spring unwinds to provide the counterbalance necessary to open the door. As the door is closed, the spring is rewound and ready for the next door cycle.
As for the springs themselves, there are a few parts you should be familiar with:
For particularly heavy doors, a duplex spring may be required to lift them. This means there will be two springs within the barrel, one inside the other. Duplex springs may also be used when the springs needed to lift the door are too long for the headroom area above the door.
How are springs for rolling doors chosen?
No worries here – your door manufacturer will do all the heavy lifting, just like an antihistamine takes care of that reaction to pesky pollen. Springs are calculated for inch pounds per turn (IPPT) and the door cycle life by the manufacturer.
Depending on the door’s lifecycle, the diameter of the spring’s wire, the diameter of the spring’s coil, and the spring’s length will be adjusted. The higher the number of cycles, the larger the wire and longer the length. Note here that the size of the spring can affect the door’s headroom.
The springs are matched to the rolling door you choose for your application, including the number of cycles it will see in its lifetime. Cookson’s rolling doors come with a standard 50,000 cycles. Higher cycle options such as 100,000, 300,000, 500,000, and more are available for applications such as parking garages, where a door or grille could see upwards of 20 cycles or more a day.
While some applications are ideal for rolling doors with springs, there are limitations. If the spring(s) required to lift the door are too large for the headroom, or the door’s cycles exceed the recommended cycle for spring doors, it’s time to move to a springless rolling door faster than you bring your plants inside for overnight frost.
How do I know if my springs are broken?
Just as it’s difficult to know when spring has begun for real instead of just a tease of a few days of good weather, it can be hard to tell if your springs are broken. In rolling security doors, the springs are located inside the barrel and obscured from view. A telltale sign to schedule an appointment with your door technician can be an overheating motor operator. Since the operator is working twice as hard to cycle the door without the assistance of springs in a spring door, it may overheat or wear out faster than usual.
Another way to determine if your springs may be broken is difficulty with manual operation. If the door can’t be opened or closed with the hand chain and you don’t feel resistance or tension, this can also be a sign of broken spring(s).
There are other times where signs of a broken spring are nowhere to be found. To confirm any security rolling door issue, including broken springs, contact your door technician or manufacturer.
How do rolling doors without springs (springless rolling doors) work?
Springless rolling doors function the same way as rolling doors with springs: they’re able to cycle open and closed through manual or motor operation. However, instead of springs providing counterbalance to lift and lower the door, the motor takes on the challenge itself.
Because it would prove difficult to get a large enough spring in the barrel to handle a heavy door and a significant amount of cycles, it’s easier to eliminate the need for them and transfer duties to a motor operator. Understandably, this means the horsepower of the motor operator will be higher, allowing it to lift the door.
So, what’s better? A rolling door with springs or a rolling door without springs?
Great question! It truly depends on the application. In a warehouse where deliveries are scheduled for once in the morning and once in the evening, a rolling door with springs would work well. In fact, the majority of closures have spring doors because the use case isn’t higher than 50,000 cycles.
On the other hand, once you get above our standard offerings, such as a parking garage for an apartment building with over 150 tenants, door cycles skyrocket, as does the need for a springless rolling door. The key is to know what kind of door you need, and then manufacturers like us can help you take care of the rest.
Are you ready to spring forward to the next season of rolling doors in your spec or your facility? Contact us here and we’ll walk you through the options.