Should You Use Glassbreak Alarm Sensors?

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Brian Rhodes
Sep 02, 2016
IPVMU Certified

It would be helpful to understand if/how/when you employ glassbreak alarm sensors in intrusion alarm designs.

A related topic is Glass Break Sensor Recommendation, where the OP asked for specific units, but the difference here is whether or not to use these sensors at all; and if so, how.

Below is general feedback we hear on this topic, feel free to add to or debate these:

Pros:

  • Glass breaks trigger alarms before an intruder has entered, offering advanced notification
  • Glass breaks can cover multiple window units, which makes them cheaper to deploy than window foil or accelerometer sensors.

Cons:

  • They aren't reliable. The variation in window types, sizes, and construction all lead to a poor expectations.
  • Most intrusion events don't happen when somebody breaks a window and climbs in, but through a kicked-in or jimmied door.

So: Do You Use Glassbreaks? Vote below:

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UM
Undisclosed Manufacturer #1
Sep 02, 2016

We don't manufacture GB sensors and I strongly disagree with those who voted that they never use them. I've seen first hand where a GB has provided early detection of a possible entry through a window. When properly installed for the correct window type and installation environment they DO work and provide excellent detection results.

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Brian Rhodes
Sep 02, 2016
IPVMU Certified

When properly installed for the correct window type and installation environment they DO work and provide excellent detection results.

Thanks. The crux of this question is 'how does someone do that'?

JE
Jim Elder
Sep 02, 2016
IPVMU Certified

I agree with Brian. "Properly Installed" is the key. I would add planning to that as well. Unfortunately the only way you can really test the sensor is to break THE window the GB is installed to protect. What happens to the sensitivity when window film is applied to the glass; curtains placed over the window, etc. Agreed you can set by acoustic tester, but, unlike motion detectors with walk test lights, how can you be assured the GB will work when needed?

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Brian Rhodes
Jan 13, 2017
IPVMU Certified

Bumping this.  For those that use/install Glassbreaks, how do you confirm they are working or spec'd properly for the task?

U
Undisclosed #2
Jan 16, 2017

Google Glassbreak tester

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Avatar
Brian Rhodes
Jan 16, 2017
IPVMU Certified

This is not a good answer.  Acoustic testers simulate noise, but how do you ensure your windows/ panes sound the same way when broken?

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U
Undisclosed #2
Jan 16, 2017

Brian,

Have u ever use/try them yourself?

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Brian Rhodes
Jan 16, 2017
IPVMU Certified

Yes, but not in most systems and generally by customer request only. I've never soothed my own skepticism enough to make common use of them.

To that point, my topic question: How does one know a particular glassbreak is spec'd properly or will perform as expected?

Using any glassbreak for every job doesn't seem prudent; so how do you select the right one?

JE
Jim Elder
Jan 16, 2017
IPVMU Certified

Brian. You forgot to mention that glass break detectors provide perimeter protection while the space is occupied (a reason why they are used often in homes). This protects people as well as stuff. Frankly, there are not many alternatives (recall foil tape?).  If it's the right application AND the right installation practice GBs  should work. I would note that the manufacture's instructions should be followed to the letter. As to window film and new curtains, place stickers on the window and behind the curtains warning that any changes could impact detection. Yearly inspections may also be considered. 

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Brian Rhodes
Jan 16, 2017
IPVMU Certified

As to window film and new curtains, place stickers on the window and behind the curtains warning that any changes could impact detection.

That's interesting.  The value in this 'disclaimer sticker' is to warrant building owner/user pause before they make changes to the windows?

U
Undisclosed #3
Jan 16, 2017

I would like to ask if anyone knows of any insurance policies or insurance requirements for a tenant to occupy certain types of real estate? If not insurance then perhaps policy or requirement from the property owner(s). Thanks IPVM.

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Brian Rhodes
Jan 16, 2017
IPVMU Certified

Hello Und3:

I'll make this its own discussion topic, but first:

Do you mean insurance requirements for intrusion alarm systems?

U
Undisclosed #3
Jan 16, 2017

I should have said the inclusion or adding of glass break sensors to a new or existing intrusion system to meet a specification, policy or requirement driven by a insurance companies or property owner.

JE
Jim Elder
Jan 17, 2017
IPVMU Certified

There are exceptional riders that will required the installation of a system. In most cases this will be a fully UL listed install monitored by a UL Listed Central station. So if you have a Vanan gogh in your basement, and wanted it insured for loss, my guess it would require at least a burglar alarm with some kind of perimeter sensors.   

AS
Ashley Schofield
Jan 17, 2017

In a retail / commercial environment I would always recommend them.
In the event of a smash n grab, the alarm would trip instantly as soon as the glass door/window is broken. If you only have motion sensors and the front door reed switch, and the car breaks the reed first, then the alarm will could go into entry countdown giving up to a minute of free time before the alarm actually trips.

I know of an ATM that got stolen in a shop (ATM was directly below the PIR) after the window smashed, and they crawled slowly on the floor for about 20 minutes to get to the ATM. Lesson learned , use glass breaks or window beams and that any alarm system must have different layers of detection...

For a home, I wouldn't bother.

UI
Undisclosed Integrator #4
Jan 17, 2017

I have a residential account with over 80 window sensors and zero motion sensors. I explained the importance of having at least one but they refused because they usually only set the alarm while they were in house. Which is a fair argument but to me is very risky for when they go away and someone breaks through a window. 

I talked them into a few glass breaks in the back of the house where a break in would most likely occur. 

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JE
Jim Elder
Jan 17, 2017
IPVMU Certified
What about the home and away feature?
UI
Undisclosed Integrator #5
Jan 17, 2017

I use glassbreaks occasionally, not routinely, and always with motion detectors. Acoustics and shock waves may not always reach the threshhold of the GB's alarm trigger, so I don't trust them to act alone without motion detectors as a backup. I've taken over accounts in which GB detectors were improperly adjusted or placed. They confuse a lot of installers. Installing GB's require careful placement and setup using the manufacturer's recommended GB tester.  GB's may not detect a small pane of glass being broken, allowing an intruder the ability to crawl through, but the motion detector would then be the next obstacle for the burglar.

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