A well-functioning door rarely draws attention. A door that is difficult to open, noisy or unreliable can create an accessibility barrier, frustrate users, increase safety risks and require repeated maintenance. Where the closer contributes to these problems, its specification and adjustment can improve how the door performs in everyday use.
Although door closers are often specified to meet compliance requirements, the choice can also affect day-to-day use and building management. ASSA ABLOY’s Cam-Motion door closers, for example, use a cam mechanism to reduce the effort required as the door opens. The manufacturer compares the movement to that of the human elbow: the opening torque falls as the door swings further, which can make even a heavy door easier to open*. An optional closing delay gives users more time to pass through. These features can be useful at busy doors, where ease of use and durability both matter. In such settings the closer has to support comfortable operation over repeated opening and closing cycles.
ASSA ABLOY’s Free-Motion range uses a different approach. In free-swing mode, the door can move without the resistance of the closer and remain open at any angle. According to the manufacturer, the free-swing function operates from the first degree of opening. When the function is active, automatic closing is suspended, so staff and visitors can pass through an open doorway. This can be useful in care settings, where residents may otherwise need help with heavy doors. The range includes options for heavy fire and smoke doors and double-leaf doors. When the free-swing function is released in an emergency, the closer resumes operation and returns the door to its closed position. The arrangement therefore retains the closing function while allowing the door to move freely in normal use.
Improving the building environment: noise and energy use
Door noise can be a source of disturbance in workplaces and shared living environments. ASSA ABLOY’s Close-Motion technology is designed to reduce noise during the final stage of closing. The closer moves the door towards the frame, then slows it over the final part of its travel before pulling it shut. The resulting sound may be limited to the latch engaging. The damped closing action is intended to reduce slamming even where wind pressure, draughts or differences in air pressure affect the door. The aim is to soften the final movement while still allowing the door to close fully.
Reliable closing can also influence indoor conditions and the load on heating or cooling systems. A field study in a Japanese shop measured air infiltration, room temperature and electricity use with the entrance door open and closed while the air-conditioning was set to 24°C**. With the door open, the measured infiltration rate was more than 21 times higher and the room was about 5°C warmer. The researchers found no difference in the air conditioner’s measured electricity use in this test. Buildings account for a substantial share of electricity use, but any energy or cost savings from keeping doors closed depend on the building and how its heating or cooling system operates.
“Of course, the security and fire safety requirements of a door closer should never be overlooked,” says Andreas Gmelin, Director and Head of Product and Innovation, Door Closer product unit EMEIA at ASSA ABLOY Opening Solutions***. He notes that a door left ajar because of wind, human error or wear can undermine access control and affect fire safety. Door closers can work with digital locks and access control systems to help ensure that a door closes after authorised passage.
Gmelin also points to quieter closing and easier access as considerations when specifying door closers for hospitals, stadiums, schools and railway stations. The choice can affect how easily people move through a building and whether the door remains easy to use over time. ASSA ABLOY’s range includes different closing functions and designs, allowing specifiers to consider ease of operation and the appearance of the hardware alongside the requirements of the door.
Further product information from ASSA ABLOY is available at www.assaabloy.com/group/emeia/solutions/topics/door-closers
*: www.assaabloy.com/group/emeia/stories/access-stories/cam-motion-ensures-everyone-can-open-the-door
***: www.assaabloy.com/group/emeia/stories/access-stories/standards-for-door-closers
