What size door closer do I need for a 36-inch commercial door?
A 36-inch (3’0”) commercial door typically requires a size 3 or size 4 closer. Size 3 is standard for interior doors at normal weight. Size 4 is appropriate for exterior doors, fire-rated doors, or doors with heavy hardware. If the closer is mounted in parallel arm configuration, size up by one to compensate for the reduced closing efficiency.
What is the difference between regular arm and parallel arm door closers?
Regular arm mounts the closer body on the pull side of the door with the arm extending to the frame head. Parallel arm mounts the closer body on the push side with the arm running parallel to the door face. Parallel arm provides a lower profile and is standard for corridor applications, but delivers approximately 20–25% less closing force than regular arm on the same closer body.
What is backcheck on a door closer?
Backcheck is a hydraulic function that resists the door being thrown open too forcefully. It engages at approximately 70 to 85 degrees of opening and cushions the remaining opening motion. Backcheck protects the door, frame, wall, and closer from impact damage. It is a standard feature on most commercial-grade closers and is especially important in high-traffic areas.
Can I use a door closer with hold-open on a fire-rated door?
A mechanical hold-open closer cannot be used on a fire-rated door. Fire-rated doors must close and latch automatically from any open position. The only way to hold a fire-rated door open is with an electromagnetic hold-open device connected to the building’s fire alarm system, which releases the door automatically upon alarm activation. This applies to all fire rating levels: 20-minute, 45-minute, 60-minute, 90-minute, and 3-hour/180-minute.
What is the maximum door opening force allowed by ADA?
For interior hinged doors on accessible routes, the maximum opening force is 5 lbf (pounds of force). Exterior doors are commonly limited to 15 lbf, though requirements vary by jurisdiction. Fire-rated doors may be permitted up to 15 lbf to ensure positive latching. Opening force is measured at the latch edge of the door with a push-pull gauge and the latch retracted.
What is the difference between Grade 1, Grade 2, and Grade 3 door closers?
ANSI/BHMA A156.4 defines three closer grades. Grade 1 closers are tested to 10,000,000 cycles and are required for high-traffic commercial openings. Grade 2 closers are tested to 2,000,000 cycles and suit medium-traffic interior applications. Grade 3 closers are tested to 500,000 cycles and are limited to light-traffic or residential use. Most commercial project specifications require Grade 1.
What door closer functions are required for a fire-rated opening?
Fire-rated openings (20-minute, 45-minute, 60-minute, 90-minute, and 3-hour/180-minute) require a self-closing device that returns the door to the fully closed and latched position from any open angle. The closer must carry a fire listing matching the assembly rating. Hold-open is prohibited unless connected to the fire alarm for automatic release. Delayed action must be specifically listed for fire-rated use. The closing cycle must comply with NFPA 80 timing requirements.
How do I know if my door closer is the right size?
Measure the opening force at the latch edge of the door with a push-pull gauge (latch retracted). For interior accessible doors, the force must not exceed 5 lbf. If the closer latches the door reliably and the opening force is within the required limit, the closer is correctly sized. If the door fails to latch, check for excessive hinge friction, weatherstripping drag, or latch/strike misalignment before increasing the closer size.
