Special Purpose Door Closers

Harsh or hazardous environments, unusual doors, makeshift additions or historical building renovations can add up to difficult installation challenges. Although today’s closers offer a wide range of install options, something special is often needed – especially in retrofit applications. This article explores closer options designed to solve unusual problems.

Other challenges arise from compliance with NFPA 80 fire codes, and LEED (Leadership in Energy and Environmental Design) goals, or special design elements that may require unusual or creative solutions. Opening force and safe passage of handicapped are important issues for Americans With Disability Act (ADA) compliance. Additional challenges can come from arched openings, various gate applications, sliding doors, walk-in freezers or other heavy applications.

History

The LCN Door Control Catalogue has an excellent saga of how Mr. L.C. Norton worked to solve wind problems for large doors at the Boston Trinity Church in the late 1800s. He soon found that spring closers resulted in loud slamming noises. Pneumatic dampers also proved ineffective.

By 1900 Norton developed the liquid door check and the era of hydraulic dampers was born. The new closer controlled back check, swing, and latching speeds, spurring intense growth and competition in the new industry.

A normal series of business moves and developments led to the current LCN closer division of Allegion. Another branch developed into the Norton company, currently held by ASSA ABLOY.

Following are some (certainly not all) of the unusual problems and solutions.

Closer Design

Closer designs include the concealed floor and top frame mounted closers that have of course been storefront staples for the last half-century. The popular surface mounted designs with parallel arm, regular arm, top jamb, corner bracket and the esthetically pleasing track arm options are also common.

Early track arm closers produced a non-lineal closing force as the leverage decreased. A roller cam assembly was developed to replace the rack and pinion drive, producing the desired consistent closing force for the track arm installation.

Corrosive Environments

Corrosive atmospheres like swimming pools, chemical plants, or environments with a salt-spray atmosphere lead to rapid failure if the closer is not really engineered for that application. For example; in one industrial application, the hardware failed after about three months. The owner later explained that the hardware was used on a plastic door in an extremely corrosive chemical plant environment.

Closer manufacturers currently address the corrosion issue in several ways. ASSA ABLOY’s Norton uses brass adjustment valves, 440 stainless steel pinion shaft, aluminum body, bronze bushings and SS arms, fasteners and parts. ASSA ABLOY’s Corbin Russwin, Sargent, and Yale use special rust inhibitors for exterior or corrosive environments. Allegion’s LCN Division provides a special rust inhibitor (SRI option) prior to the application of the LCN powder coat finish.

dormakaba provides the STA closer series for exposure to severe climate and corrosive environments. The corrosion resistant aluminum body uses stainless steel pinion, spring adjustment, fasteners, arm assemblies, and brackets. Stainless steel or plastic covers are available options.

Weather Conditions

Outdoor applications and extreme weather conditions demand weatherized products to defend against heat, cold, and wet conditions. Most manufacturers now provide stable temperature hydraulics (typically down to -40 F) that also lubricate. No seasonal adjustment is needed for the makeshift clamp-on auxiliary heater shown at right. [1]

One should note that there are some budget products available that may not perform as well exposed to inclement weather or extreme conditions. From time to time we see photos of exploded closers.[2] Possible causes are undersized products, wind, or contaminated casting processes. ASSA ABLOY companies, dormakaba, LCN, Norton and some better import products offer pressure relief valves to prevent damage to closer, door and frame.

Arched Openings

Arched doors are one of the difficult mounting situations you may face. Allegion’s Lori Greene publishes a really interesting blog called “idighardware.com.” One of her posts covers “Closers for Arched Doors.” Also, under the “Closer” section you’ll find quite a number of reader-submitted photos of challenging, weird and failed closer installations. This is a very instructive and entertaining website.

Power Assist

Power assisted door operators are installed in commercial and institutional facilities with increasing frequency. High energy operators are used for fast-opening swing or sliding entrances with high traffic, while low energy doors are more commonly used for handicapped access with gentle operation. Search: The Distinction Between Low and High Energy Door Operators for a good discussion of the issues. Delayed action or motion sensors like in Norton’s SafeZone^® keep the door open while walkers or wheelchairs negotiate the opening.

Regenerative Power

Regenerative Power can be used where wiring cost is prohibitive or maximum energy savings are paramount. The Norton 5800 ADAEZ^®low energy operator captures closer energy to charge the on-board high efficiency battery for doors up to 250 lbs. Radio frequency push buttons are standard, and a hand-held remote is available. Dry contacts provide an output for lock or strike activation. Long life batteries allow about 2,000 operations before recharge. The battery-only operation is self-sustaining with about 80 cycles per day, of which 25% are battery powered. A plug-in 24VDC power pack can keep the battery pack charged when power is available.

Special Applications

Other special applications can include hospital, detention or vandal-prone areas. Antimicrobial finishes are designed to inhibit the growth of bacteria in the healthcare environment. ASSA ABLOY companies and dormakaba closers offer this option.

Corridor applications frequently use LCN’s SENTRONIC^® closer that is normally held open, but electronically released by a fire alarm signal. Another version remains closed, but after being opened 80 degrees, is held open by a built-in motion sensor during continuous traffic.

Heavy duty anti-vandal and detention closers like the LCN 2210 track closer conceal the body in the top jamb and the track in the top of the door. TORX center-pin fasteners reduce susceptibility to attack. Historical renovations are often done with Norton’s 78 series or Yale’s 1900 series traditional pot belly style closer.

Weight Issues

Heavy doors for walk-in refrigerator or freezers pose some special issues. Kason Industries in Newnan, GA specializes in hardware for walk-in cold storage. A spring-action closer engages as the heavy walk-in door nears the frame, helping overcome resistance of air pressure and sealing gaskets.

Spring hinges have long been popular for self-closing fire rated doors to residential garage areas. Bommer has built a solid reputation in the industry for their single and double-acting spring hinges and pivots. Taiwan based Waterson has developed an adjustable dampened spring hinge for doors up to 440 lb. These hinges are available with either a mechanical or hydraulic damping process. This offers an interesting option for residential and light commercial applications.

Exterior Gates

Exterior Gates present some interesting challenges at times, but there have been some notable recent developments. Locinox, a Belgian company with Chicago based distribution builds a series of hydraulic gate closers in several sizes, accommodating a wide range of applications.

“Michigan based LockeyUSA gate products are distributed through normal lock supply channels. Nine basic gate closer styles are available. The TB100 hydraulic dampened closer is similar in design to the Kant-Slam product. A series of adjustable tubular style closers are controlled with nitrogen gas. The TB950 Magnum concealed hinge-closer is designed for high-use gates up to 250 lb. Closing and latching speeds are adjustable and that product is rated for -40 F to +122 F temperature ranges.”

The venerable Kant-Slam hinge-side gate closer is currently produced by the Hi-Lift Jack company in Bloomfield, IN. We’ve personally observed the product function in weather conditions of minus 35 F to +122 F (Minnesota and Arizona). The hydraulic damping performed as advertised.

Sliding Doors

One other product we recently observed was developed to smoothly and safely close sliding doors. A series of closer ranges handle doors from 10 to 500 lb. A spring loaded reel provides easy opening and a gentle return motive force. The interesting part is a rack and pinion deceleration zone that allows gentle and positive sliding door closure. The Tokyo based Nitto Kohki USA company has offices in the Chicago area, and products are sold direct from their call center and offered on Amazon.

And finally, some pictures of unusual applications. Left to right: Cal-Royal doubled closer, LCN closers offset to fit communicating doors, and a corner bracket pot belly application.[3]