|Power Assisted Door Closers|
|Written by Harold Fink, Locksmith, CRL CPS|
|Thursday, 21 January 2010 11:04|
Power Assisted Door Closers
The advent of the Americans with Disabilities Act (ADA) of 1990 created many changes in the door and hardware industry. Power assisted door closers are one of the commercial door hardware products that evolved as a result of this legislation. The Americans with Disabilities Act placed broad emphasis on accessibility. The most sweeping change in door hardware came in the form of a lever handle, which provides increased access over the knob. The replacement of knobs with lever handles only partially complied with accessibility requirements. Greater accessibility for Americans with disabilities has been achieved through the use of commercial door locking hardware that is easier to operate, required to be installed at accessible heights, and installed on doors that are easier to open.
ADA compliance also increased the market demand for automatic doors and power assisted doors. The ADA element 10, section 4.13.12, establishes the guidelines for the compliance. The door and hardware industry primarily specifies the low-powered slow opening type of power-assisted door closer. The fast-opening supermarket type of doors are not on the realm of builder's hardware discussed in this article.
There are many sizes, types and shapes of power-assisted door closers on the market and they must comply with two ANSI standards. ANSI A117.1 requires door assemblies to conform to this standard "for buildings and facilities" to provide accessibilty and usability for the disabled. ANSI/BHMA A156.19 states the conformance specification "for power assist and low energy power operated doors". Some power door operators even comply with NFPA 101, the Life Safety Code. All power assisted door closers must be UL labeled and meet the UL requirements.
Some manufacturers can provide two or three grades or types of power assisted door closers. Some are air operated, some are electrically operated.
The next time you enter a drug store or a grocery store, look at the entry system. If the doors are power-operated, you may notice floor mats and/or motion sensors. You step on these, or your movement is sensed, to open the door, but if someone is standing on the other side, the door may not open. You may also notice guard rails and one door will open in, the other will open out to control traffic and reduce the chances of someone being knocked down. All these safety features are necessary because the doors open fast and hard. Some manufacturers will furnish a reflective beam-type sensor to open the door and also prevent the door from being opened if someone is in the path of the doors.
This is not necessary with the low energy power-assisted door closer. The door or doors must open slowly, stop when it strikes someone and reverse direction if the power fails. The door operator will act as a standard door closer, with added benefits to those with disabilities. The door will open slowly, usually no faster than three seconds from open to back check. The operator shall not require more than 15 foot pounds. If there is any type of locking device on the door, the latchbolt must disengage before the door opens.
The most common application for a power-assisted door closer is the public building entrance designated as the handicapped entrance. Power assisted door closers can also be found in restroom entry doors, computer room entry doors, office entry doors or even entry into a specific department of a building. They can also be used on the entry to exam rooms of an emergency room area of a hospital.
These closers can be used on any types of doors - wood doors, hollow metal doors or aluminum storefront doors. They can be used on labeled fire doors if they are wired into the fire alarm panel. This will de-energize the automatic feature of the power assist door operator and allow the power assisted door operator to operate as a standard hydraulic door closer. The door must be self-latching and self-closing to comply with NFPA XO.
Any type of power-assist door closers must be electrically wired in some manner. This would require the services of a licensed electrician, for either low voltage, high voltage or both. Even though some systems plug into the wall, the accessories must be wired. Check with the local code authorities before you attempt the wiring installation of a power assisted door closer.
Lets look at the handicapped entrance to a church to see what products can be used to comply with ADA (Americans with Disabilities Act) requirements. The door is a narrow style aluminum storefront door with a glass transom and sidelights. The door has an Adams-Rite style dead latch lock installed with a lever handle on the inside.
First, select an operator than can be surface mounted to the transom bar. You would need a 115V AC, 15 amp receptacle close by (Within 2 feet) of the operator. This is where the licensed electrician may be necessary. A key switch would be needed to de-energize the system on the entry side after hours. You would need an electric strike for the latch lock along with a lock guard. The electric strike would have to be energized before the door operator can open the door. The electric strike would have to be fail-safe (power off, door locked). You can not rely on someone activating the latch bolt hold-back feature on the Adams-Rite style of dead-latch lock.
To activate the power-assist door operator, you could either use a wired wall switch, a wireless wall switch or a beam type sensor. Your choice would have to be installed on each side of the door. You may have to install a call button to be used in case someone forgets to activate the system on the entry side with the key switch. Exiting will always be allowed to comply with NFPA 101 Life Safety Code. For security reasons, mount the key switch on the interior (exiting side) of the door. Leave the key cylinder installation on the latch lock exterior for a key override feature in case of power failure or entry after hours. The key switch should be on a restricted keyway, single-keyed (SKD-1), with a limited number of keys issued.
The same basic system would apply even if the door had an exit device installed instead of the latch lock. The exit device must be electrified and wired into the power assisted door operator. Here again, don't rely on someone to dog the exit device at the end of the day. The electric strike option would only work if the exit device was a rim type with a latchbolt. If the exit device was a vertical rod, you could use an electric strike, but the bottom rod would have to be omitted.
If the door had a locking system, either an electric strike or an electric exit device, you would have to use a time delay relay in a power-assisted door closer system.
If the power-assisted door closer, or operator, is used on a restroom door, you would not normally be concerned with a locking or latching system. Most restrooms have a push/pull plate for opening and closing. If the door has a lever latch and the door is not a fire door, remove the lever latch and install a push/pull plate. Some restroom entry doors from a corridor may be fire doors to comply with code requirements. If this is the case, you need to use a fail-safe (power-off, door latched) electric strike. Depending on the wall condition, this could be a problem. Just remember that all fire doors must self-closing and self-latching. Never consider disregarding this for the sake of saving a few dollars.
If the system is to be installed in a pair of cross-corridor fire doors that exit from a secured area to a lobby, you must use electrified labeled fire exit hardware. The system must then be wired into a smoke detector system or the fire alarm system. This would definitely require the services of a licensed electrician familiar with fire alarm systems. If he or she is not, you need the services of a commercial fire alarm installer. It would be best to contact the original fire alarm installer to be sure the integrity of the system is maintained. All the materials used on this type of opening must meet the UL requirements for use in fire doors.
Power-assisted door operators are not an easy system to provide and install. You may have to provide or refer the services of other trades. You must comply with all codes and standards where applicable. Installation of a power assisted door closer is likely to include installation of an electronic access control system that works with it, to control access through the door and allow for proper egress and entrance for those with disabilities. You should have the ability to install and service these access control systems to be of full value to your customer. If you have the electrical knowledge and the ability to put the system together and service it, by all means offer these products to your customers.
|Last Updated on Saturday, 30 January 2010 23:49|