Glass Break Sensors vs. Window Contact Sensors: Which Protects Windows Better?

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A ground-floor window can have a security system watching it and still have an important gap in protection. A standard window contact sensor detects when the window opens, but it does not respond simply because the glass has shattered.

That distinction is why homeowners comparing a wireless security system may encounter both window contact sensors and glass break sensors. They monitor different events, and in some homes, using both provides broader coverage.

Protect what matters most! If you’re unsure which sensors your home needs, ADT can provide a free quote and help assess your property’s entry points and security needs.

Do I need glass break sensors or entry sensors?

Window contact sensors and glass break sensors detect different types of intrusion. A contact sensor typically alerts when a protected window opens, while a glass break sensor detects the sound pattern associated with shattered glass. Homes with accessible ground-floor windows may benefit from using both as part of a layered security system.

How do window contact sensors work?

Window contact sensors are designed to detect when a window is opened. A typical contact sensor uses two pieces positioned together when the window is closed. When the window opens, the separation triggers an alert.

ADT’s Premium Door/Window Sensor is a wireless sensor that sends mobile alerts when a protected door or window opens. It also includes shock-sensing technology designed to detect abrupt or forcible attempts at entry.

Related: Are Home Security Systems Worth It for Townhomes and Condos With Shared Walls?

What a Contact Sensor Detects

A contact sensor is well-suited to scenarios where an intruder opens the window to enter.

For example, if someone raises an unlocked window from the outside, the sensor can detect that change and trigger the security system. But a contact sensor isn’t specifically designed to detect shattered glass while the window remains closed.

That distinction becomes significant with large panes, fixed windows or glass doors that could potentially be broken rather than opened.

How do glass break sensors work?

Glass break sensors listen for the characteristic sound associated with breaking glass. Instead of monitoring whether a window has physically opened, they monitor the surrounding room for an acoustic signal associated with shattered glass.

ADT says its Glass Break Sensor identifies the unique audio pattern of a shattered window or glass door. The sensor uses machine-learning algorithms to distinguish that sound from noises such as slamming doors, dropped objects and clinking dishes.

What a Glass Break Sensor Detects

The primary advantage is that the sensor is designed to recognize glass breakage itself.

ADT’s current Glass Break Sensor has a detection range of 2 to 25 feet and can cover multiple windows in the same room when positioned appropriately. ADT recommends mounting the sensor on a wall or ceiling within the specified range and maintaining a clear line of sight to the protected glass.

That makes a glass break sensor useful in rooms with several windows or a large sliding glass door.

Glass break sensors vs. window contact sensors: What’s the difference?

The two sensor types, therefore, shouldn’t necessarily be viewed as competing products. They monitor different events.

Which sensor is better for ground-floor windows?

For an operable ground-floor window, a contact sensor provides direct detection when the window is opened. A glass break sensor provides a different layer of detection if glass is shattered.

The right configuration depends on the window and the room rather than simply choosing one sensor for the entire house.

Use Window Contact Sensors for Accessible Openings

Contact sensors make sense on windows that can be opened from the outside. They directly monitor the opening itself.

ADT’s Premium Door/Window Sensor is also designed with shock sensing, which ADT says detects abrupt or forcible attempts at entry. That provides another form of detection beyond simply knowing that the window has opened.

Consider Glass Break Sensors for Rooms With Multiple Windows

A glass break sensor can monitor multiple glass surfaces within its coverage area. ADT specifically identifies rooms with large windows, sliding glass doors and multiple window panes as suitable applications for its Glass Break Sensor.

This can reduce the need to place an individual glass-break device at every window.

If you’re dealing with several vulnerable ground-floor windows, ADT can assess the layout and recommend sensor placement as part of a professionally configured wireless security system.

Can you use glass break and window sensors together?

Yes. Using both types creates complementary detection.

A contact sensor monitors the opening. A glass break sensor monitors for the sound of shattered glass. ADT describes its Glass Break Sensor as perimeter protection and notes that it can complement motion sensors and cameras in a layered security system.

For a home with several accessible windows, a combination can be useful because the sensors are watching for different events.

A security camera adds another function: visual information about what happened. It doesn’t replace either sensor because a camera and an alarm sensor serve different purposes.

Where should you put glass break sensors?

Placement affects the area a glass break sensor can monitor.

ADT says its current Glass Break Sensor should be mounted on a wall or ceiling within 25 feet of the windows or glass doors being monitored, with a clear line of sight. Its product information also says the sensor should be mounted at least 6.5 feet above the floor.

When planning a wireless security system, consider:

• Large windows: A room with a broad expanse of glass may benefit from glass-break detection.
• Sliding glass doors: These provide a large glass surface and are specifically listed by ADT as an application for its sensor.
• Multiple windows: One glass break sensor can cover multiple windows within its stated detection range.

Avoid assuming that one sensor will cover an entire floor. Walls, room layout and sensor placement affect coverage.

Related: 7 DIY Home Security Mistakes That Could Leave Your House Vulnerable

What should you choose for your home?

There isn’t a universal substitute for one sensor type.

• Choose window contact sensors when your priority is detecting an open window or door.
• Consider glass break sensors when your home has rooms with large or multiple glass surfaces where detecting shattered glass is important.
• Consider both when you want the security system to monitor both window openings and potential glass breakage.

ADT currently offers both wireless window/door sensors and wireless glass break sensors. Its Glass Break Sensor communicates with the ADT Base and sends notifications through the ADT+ app when glass breakage is detected.

The best configuration depends on your home’s window types, room layout and entry points.

Get a Free Quote for a Wireless Security System

If you’re unsure whether your ground-floor windows need contact sensors, glass break detection or both, ADT can evaluate your home’s entry points and available security options.

Request a free quote from ADT to discuss a wireless security system designed around your home’s windows, doors and other potential entry points.

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