Opening Up About Door Closers
Apr 1, 2008 12:00 PM, By Ryan Rouse
A humble, unsung component delivers in many uses
The term “door closer” barely begins to explain the many purposes of these widely used devices. Perhaps “door controller” would be a better term considering the various functions they perform. Their role in protecting the people and assets on the “other side” include these benefits:
Protection for the components of the entire opening.
Safe and easy passage through the door.
Reliable security for people and assets.
Adherence to fire and life safety codes.
Protecting the opening is one of a closer's main functions, especially in high-use high-abuse situations. These may include high-cycle doors, such as those at a mall entrance, in a hospital, stadium or auditorium, and doors at a school or university that encounter abuse from more forceful opening and back-checking. Door openings are one of the most highly used and abused components within any facility, yet they must enable smooth traffic flow while maintaining safety, security and the overall facility experience.
The presence of high winds or pressure differentials may require greater closer force to protect exterior doors from severe damage. Heavy-duty concealed or surface-mounted closers offer an extra measure of protection in these applications, but their use must be balanced with the need to avoid making doors too difficult for people to open. Proper closer adjustment plays an important role in achieving the balance needed in these situations. A back-check selector valve, delay function and/or other adjustments make it possible to tailor the different stages of closer operation more closely to the needs of a specific opening.
Some closers incorporate a pressure relief valve to prevent damage to the closer under overload conditions, which may be severe enough to cause cracks in the closer cylinder. Closers with cast-iron cylinders generally will not require pressure relief valves, because the material's innate strength resists cracking, which ensures that the closer opens and closes smoothly.
Adding an overhead stop will help protect the closer and the rest of the opening against excessive forces. Also important is proper installation and adjustment of the closer itself.
Making it accessible
Protecting people from the door can include preventing accident or injury from a door that closes too quickly, minimizing difficulties that children or frail adults may have in opening the door if the closer force is adjusted too high, and meeting accessibility guidelines for those with disabilities.
Closers that are adjusted too strong to meet Americans with Disabilities Act (ADA) guidelines will also be difficult for other people to open. If conditions permit, it may be possible to accommodate ADA compliance by adjusting the closer force to Size 1. But in most cases, power door operators are the best available option to meet these needs. Typically one door in a bank of doors may be all that is required. In addition to serving people with disabilities, it can add convenience for parents with strollers or people with armloads of packages as well. Properly adjusted conventional closers on all other doors will ensure that they close and latch properly.
In the past, seasonal adjustments were a common attempt to meet these problems, as well as those encountered on exterior doors exposed to temperature extremes. Today, the availability of closers with all-weather fluid has made this ritual unnecessary.
Ensuring security is a critical closer function. No matter how sophisticated or expensive the locks, latches, exit devices, card readers and electronic security systems are, if the door doesn't close properly, latching will be inconsistent, and security will be compromised. This can put both people and assets within the building at risk. One facility director spent thousands of dollars on electronic access control, magnetic locking and proprietary keying systems, only to find that these measures were wasted because the doors would not close all the way to latch and lock.
Security problems like this may arise from improper installation, either in closer mounting and adjustment or with related hardware. For example, if latch bolt guards are not aligned properly, it may create enough friction to prevent the door from latching. To prevent closer adjustment tampering and enhance security, closers can be equipped with metal covers mounted with Torx machine screws.
Manufacturers are constantly working to improve performance and enhance closer functions to provide greater security. New designs now being developed will self-adjust as their environments or operating conditions change.
Environmental control is provided by door closers because they keep doors closed to maintain the environments inside and exclude those outside. It makes little sense to waste money and compromise comfort levels because heated or conditioned air is leaking outside when a door doesn't close securely. Likewise, temperature or weather extremes that can enter a building through a partially open door can cause damage as well as discomfort. Strong winds can cause damage to uncontrolled doors as well. Inside a building, closers maintain pressure differentials in such areas as stairwells and vestibules.
Leaking closers are both an environmental problem and a potential hazard to those entering and exiting a doorway. The oil inside the closer drips down and can make floors extremely slick, not to mention staining clothing and personal belongings of those passing beneath the closer. More importantly, when the oil drains from the cylinder, the closer's ability to control the door is lost. If this were to occur, the door swings freely and could lead to personal injuries as well as costly damage to the door and frame.
Leaks typically are caused by either an o-ring malfunction or cylinder cracks. An o-ring malfunction often results from excessive use or abuse of the opening that can cause the o-ring seal to wear and create a leak point. A second way the pinion seal can malfunction is most commonly found in aluminum closers with steel pistons. The rigid steel piston can wear on the softer aluminum body creating tiny metal contaminants. These abrasive fragments can quickly wear an o-ring to create a potential leak point. Another potential malfunction is cracking in the closer cylinder body. Abusive operation can create excessive internal pressure in the closer, causing the cylinder body to crack.
If leaks occur, several options exist to solve the problem. One is to move to a more durable material structure such as cast iron. Another option may include moving to the next model size in durability. One manufacturer offers a heavy-duty cast iron closer with a 10-year “no leak” guarantee that can help ensure the problem will not recur.
Fire or smoke barrier
Fire/life safety is a classic conflict between two important factors. For door closers, one of the most common problems is with fire barrier doors, particularly for stairwells. As with security, if the door doesn't latch properly, the opening isn't protected. The problem can be especially acute when air conditioning is operating, which creates a large pressure differential between a stairwell and hallway. This has a similar effect as a strong wind and calls for careful closer selection, installation and adjustment to ensure compliance to both the fire codes and ADA.
Fire or smoke barrier doors must remain closed to be effective. However, to allow traffic to flow, they may be held open by electromagnetic holders that are wired into the building's fire alarm system or have internal detection capability. There are a variety of options available that allows one to hold a fire door open and meet fire codes. Options include magnets wired to the central fire panel or integrated closer/detector. A unique option accomplishes the same goal of holding open a fire door without the need to pull wires and provide a power supply.
An appealing opening
Visual appeal doesn't have to be sacrificed as door closers are selected to provide all of the above functions and also comply with building codes. It doesn't have to be difficult or expensive to achieve an appealing opening. One approach is to use a concealed closer, which is mounted out of sight in the door or frame. These are available in heavy-duty models for high use high abuse applications as well as for fire-rated doors with openings up to 180 degrees. Manufacturers offer a choice of cover designs, including slim-line covers, full covers, designer-series covers and as many as 150 or more different powder-coated finishes. Metal covers add security as well as improving appearance, especially when plated. One manufacturer offers a Bright Metal Metallic finish, which is an economic alternative to plating yet offers similar aesthetics. When appearance is a concern, it is advisable to work with a manufacturer that offers full suites of hardware that are coordinated in style and finish.
One way to achieve a consistent appearance where applications vary throughout a facility is to use similar covers but different closer bodies. For example, a building may use heavy-duty closers on doors that are used frequently, but less expensive models on janitorial closers. To unify their appearance, it may be possible to use the same cover design on all units. Whenever a standard design doesn't seem to answer the need, it is advisable to check with the manufacturer and see whether there are any alternative solutions.
Ryan Rouse is product manager of LCN Door Controls for Ingersoll Rand Security Technologies, Carmel, Ind.
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