How Do Automatic Doors Know The Correct Time to Open?

October 19, 2022

Automatic doors are a great choice for your home or business and provide numerous convenience and accessibility advantages. In this guide, we outline the different types of automatic door technology, how they work, and the advantages of each.

How Do Automatic Doors Know The Correct Time to Open?

There are numerous types of automatic doors, but they all operate according to the same principle. Essentially, the door has a mechanism – an automatic door opener – that allows it to “detect” that someone is standing near the front of the door. Once that detection has been made, the door triggers itself to open automatically. A properly functioning automatic door will stay open for the appropriate amount of time for a person to pass through and will shut automatically once the person is through.

Although all automatic doors operate according to this method, they may have different ways of achieving this result. In the next section, we break down the different types of automatic door sensors, how they work, and their advantages/disadvantages.

How do automatic door sensors work? How do automatic doors detect people?

Here we take a look at how some of the most popular types of automatic doors work:

Motion/Infrared Sensors

swing door operator example from Texas Access Controls

The most common types of automatic doors utilize motion-sensing technology. As the name implies, the automatic door sensor detects when something in its range is moving, triggering the mechanism to open the door.

However, not all motion-sensing automatic doors use the same type of motion-sensing technology. The two most popular types of motion sensors are microwave and infrared:
  • Microwave sensors are useful for detecting motion, and the sensor is most commonly installed above the automatic door. A microwave beam is transmitted from the device and is able to cover a large area in front of the door. The sensors are effective at detecting motion in front of the door, which means they are less adept at detecting stationary objects or very slow-moving objects.
  • Infrared sensors can detect changes in temperature. When they sense a temperature change in the area (for example, someone approaching the door), the doors are triggered to open. Infrared sensors emit infrared and detect “reflected” infrared from objects in the area. This allows them to detect any change.
  • Both: High-quality automatic doors often use a combination of different types of sensors. This allows one sensor to compensate for the other should there be a defect or oversight. For example, if both microwave and infrared sensors are installed, then an infrared sensor might detect an object that is moving too slowly or standing still.

 Pressure Sensor

Some doors operate via pressure sensors, located on the ground in front of the door. These sensors trigger the door to open. Pressure sensors were the first type of automatic doors introduced and sometimes can actually be considered somewhat dated. This being said, this option can be more affordable, so you will often still see them at many locations

These doors still hold functional advantages. The pressure sensor can be installed to pass through the automatic door. In other words, it can be laid out to cover both sides of the door and the area through the doorway. This ensures that pressure remains on the door as the person walks through and that the door will not unexpectedly shut.

Other Access Control

elegant glass sliding door at the front of a restaurant

Some automatic doors utilize sensors that are meant to control access to the door itself. For example, instead of detecting people, the door can detect key cards, fobs, or other electronic components that trigger the doors to open. This is useful for residential, business, education and many other types of facilities. Depending on the strength of the signal detector, these doors might require the person to touch their access credentials near the sensor or will automatically trigger the doors when the person is nearby (holding their credentials).

How long does it take for an automatic door to open?

Automatic doors should, as the name implies, automatically open as soon as they detect someone in front of the door. A quality automatic door should open within seconds. Typically, they should remain open for a minimum of five seconds before shutting to allow the person time to pass through.

What are the advantages of automatic doors?

Here we examine the various advantages of automatic doors. Consider these factors to decide whether your business can benefit from an automatic door:
  • Convenience: The obvious advantage is convenience. Because customers don’t have to physically open the door, they can more easily enter the store or business. This small distinction might be the difference between a customer entering and not.
  • Accessibility: Automatic doors make your business more accessible for the mobility impaired. Not only is this a courteous way to accommodate everyone, but it might actually be required by law in your area. In the USA, ADA regulations might legally mandate that you install a handicap door.
  • Promotes Foot Traffic: Although it may not seem so, automatic doors can go a long way to promoting foot traffic into your business. Because the doors open automatically, the customer may perceive a more “welcoming” environment and be more interested in entering your store. Many businesses with automatic doors have seen their foot traffic increase.
  • The American Association of Automatic Door Manufacturers (AAADM) did a research study that surveyed 447 consumers. The study found that 98.9% of consumers prefer automatic doors.

Texas Access Controls revolving door


As you can see, there are several popular varieties of automatic doors, each with its own advantages and disadvantages. Use our commercial door service guide to find all of the resources you need to help decide the type of automatic door that is most appropriate for your facility and the ‘know how’ to keep your doors working 24/7.

How Do Automatic Doors Know The Correct Time to Open?

Previous Back to list Next


Automatic Doors