Automatic doors are a fairly recent technology that have become a standard part of commercial building layouts. But how do they work, and why are they even important, aside from the convenience of a hands-free entry?
The system starts with a sensor or intercom that triggers an electric motor to open the door at the right time to let a person through, and then close behind them. Automatic doors create a smooth transition from the outdoors to the indoors, but the other benefits they offer include increased security, reduction of germs on surfaces, increased energy savings, and compliance with accessibility regulations.
Let’s talk a bit more about the types of automatic doors, how their sensors work, and why they are important in a commercial setting.
Types of automatic door sensors
There are three different types of automatic door sensors: pressure, motion detection, and audio/visual intercoms combined with access control.
Pressure sensors are the original automatic door sensors and originated with the first models in the 1960s. The pressure sensor is a large mat that is placed beneath the floor surface on both sides of the door. It detects a change in pressure when a person or people step on–and the automatic door opens–and when they step off–and it closes.
Motion detectors come in two types: passive infrared (PIR) and microwave. PIR sensors detect the heat signature of a human body. Microwave beam detectors send out a carpet of microwave pulses and measure how they reflect off moving objects. Microwave motion detectors can cover a larger area than PIR sensors, but they are more liable to electrical interference and also more expensive.
Audio and/or visual intercom locking systems are a form of security access control for automatic doors. In this case, access is limited to a small list of authorized people, such as employees or tenants, and not to the general public.
Authorized agents on the outside can use a key, key card, or fob to unlock the door, which then opens hands-free. And with an intercom system, residents or employees inside the building can use the audio-visual functions to manually allow approved visitors to enter by remotely opening the door.
Access control and automatic doors
Access control systems for automatic doors offer locking mechanisms along with useful surveillance features such as audio and visual recording.
These systems have also become highly integrated. A decade ago, the intercom, camera, and electronic lock would all have to be essentially separate features hardwired together with a limited-functionality interface, probably on a two-tone calculator-like LCD screen.
But in today’s security technologies, automatic door access control units combine all those features and more:
- Wide angle cameras
- High-def video and audio recording
- A/V storage on an in-house server and/or the cloud
- Remote viewing from a desktop app
- Sync with a mobile app
- Touchscreen interface (e.g. Butterfly MX or Aiphone)
Many of these access control systems can also be tied into a larger security system, incorporating CCTV and interior sensors. This full suite of devices can then be accessed and monitored from a desktop app control center.
Types of automatic doors
The different styles of automatic doors are appropriate for different settings.
Sliding automatic doors are typically made of transparent glass and work well in places where there is two-way traffic. The electric motor that opens them is housed in a unit above the doorway, and the doors slide on fixed tracks.
They are very common in retail buildings and many office buildings as well. Their large size makes them ideal for settings with a high volume of traffic.
Revolving automatic doors use a central electric motor to keep the door in rotation, and allow simultaneous entry and exit–as well as adding a sense of style to a commercial building.
They cannot admit too many people at a time, so they are better for lower-traffic situations.
Swinging automatic doors can be solid wood or metal, or transparent glass. They are controlled by an electric motor connected to a hydraulic “arm” that pulls and pushes the door open or closed. Because of their heavier weight and solid construction, these doors offer more security than the others on this list.
You’ll find these in apartment buildings, in office buildings as interior doors, and in commercial warehouse space.
Other benefits of automatic doors
Aside from ease of use and increased security, automatic doors have some additional benefits.
They make it easier for those with mobility issues to enter and exit a space. Wheelchair users as well as those with crutches or canes cannot easily open a normal door, so having an automatic door open to provide them access is often a basic stipulation in accessibility regulations.
Automatic doors save energy by optimizing the length of time that the door is open. This decreases the amount of heated or cooled air from inside the building that can escape to the outside.
Touchless entry through an automatic door also prevents the spread of germs, which is a particularly helpful benefit in these post-COVID times.
Final thoughts
An automatic door might seem like an exceptionally simple piece of today’s built environment, but look a little deeper and you’ll find a cleverly designed and implemented device that makes it more convenient and safer to enter and exit a commercial facility, warehouse, multifamily housing or office.
