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Smart Home Security Sensors: A Beginner’s Guide

Home Security | Security Products

Home security and detection, detection and home security — these things go hand in hand! The ability to be aware and ready to react when something is wrong is the cornerstone of security alarm systems for your home.

That’s why security sensors are such a big deal; detecting and reacting is what they do. If you’re shopping for home security, you will immediately hear about a variety of sensors and detectors that do different things. But with all the options available — and the different ways they work to help protect us — it’s easy to get overwhelmed and confused.

Here’s a quick beginner’s guide to the world of security sensors!

What is a security sensor?

A security sensor is a device used to detect events, movements, or changes in its environment. In a standard security system, detection devices are synced with alarm panels and may operate on RF, Z-Wave, Zigbee, or WiFi. They can be used indoors or outdoors, and help create fully-integrated, multi-layered protection.

How do security sensors work?

Security devices for your home use a variety of sensor technologies, depending on what that sensor is searching for.

Guardian Protection infographic showing a check list of items that Security Sensors can detect

Here are all the sensors and detectors that serve a critical role in the safety and control of a smart home, and how they work.

1. Door and window contacts/sensors

Use: Receive an alert any time a monitored door or window is opened or closed.

A doorway with a door sensor placed in the corner

How do door and window contacts work?

Door and window security sensors are made up of two pieces: a magnet and a sensor. When the door or window is opened and the magnet and sensor separate, the sensor will alert your security system. In some cases, systems can also send a notification to your smartphone or computer. These notifications can be customized, so you can get a quick idea of what happened and where.

People also ask: What if a door or window is left open too long?

When integrated with a smart home security system, you can create a rule that anytime a window or door is still open at a certain time, you receive an alert!

Learn more about smart home integration.

2. Motion detectors

Use: Alerts you to movement within an environment. Great for rooms that don’t get a ton of activity, and for covering rooms with multiple doors and windows when no one’s home.

How do motion sensors work?

Motion sensors are usually considered “active,” “passive,” or dual tech/hybrid.

Passive infrared (PIR) sensors are called passive because they don’t send out any energy to detect movement. Passive sensors detect changes in temperature, making them ideal for sensing body heat from people and animals.

Active sensors — also known as radar-based motion sensors — emit radio waves or pulses that can reflect off objects and report back to the device. Active sensors contain an optical, microwave, or acoustic sensor, as well as a transmitter.

A dual tech sensor uses multiple methods, often combining PIR tech and radar.

People also ask: Can I use a motion detector if I have pets?

A dog running through a doorway with a toy in its mouth

Yes. Look for a pet-friendly motion detector that can ignore pets up to 85 lbs.  

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3. Glass break sensors/detectors

Use: Detect the sound of breaking glass, such as a smashed window. Great for monitoring rooms with one or many windows, like a sunroom.

How do glass breaks work?

If a burglar doesn’t open the window and just breaks the glass, these sensors are designed to not only listen for the sound of breaking glass, but also the percussion of the impact.

People also ask: Where should I put my glass break detector?

While this depends on the layout of your home, generally, focus on rooms with ground-level, easy-to-reach windows.

4. Smart sensors

Use: Place on household objects that you would like to monitor.

How do smart sensors work?

Multi-purpose wireless smart sensors can go pretty much anywhere within range of your security panel. They are just like door and window contacts, using a magnet and a sensor that alerts when separated.

Hand holding a smart phone showing a Guardian Protection app notification

They’re often used on things that are restricted or off-limits, like gun safes, medicine cabinets, or even a video game console that the kids are a little too obsessed with.

People also ask: Are smart sensors helpful with elderly parents?

Man reaching for a medicine bottle in medicine cabinet

Yes, because they can alert you to important or even routine activities. For example, sensors on a medicine cabinet can indicate that a person is regularly taking their medication.

5. Room temperature sensors

Use: Create a more balanced temperature throughout your home, and see the temperature in different parts of your home. Requires pairing with a smart thermostat.

How do room temperature sensors work?

Temperature sensors work together with smart thermostats to reduce temperature variations from room to room. After you set your smart thermostat to your ideal temperature, the temperature sensor will help ensure that the temperature stays consistent.

People also ask: What if temperatures get too high or too low?

Simply set up alerts! Room temperature sensors let you decide what temperatures are too high and too low, and can send you alerts when something is wrong.

6. Garage door sensors

Son and father in car with Guardian Protection notification, "Garage door was left open"

Use: Always know the open/close status of your garage door.

How do garage door sensors work?

Garage door sensors work with motorized garage door openers to monitor the opening and closing of a garage door. The device is referred to as a tilt sensor, which is designed to detect angular changes and inclinations.

A major benefit of garage door sensors is remote access via mobile app. You won’t need to get out of bed in the middle of the night, or turn your car around halfway to work, to double-check if you left the garage door open. You can just check your smartphone app!

People also ask: Do I need a functioning motorized garage door opener to use a garage door sensor?

Yes, you need to already have a working opener installed to get the benefit of smart garage door features.

7. Flood sensors/water sensors

Use: Detect the presence of water. Helps prevent water damage and catch leaks early.

How do water detectors work?

Water sensors for home feature a probe that can be placed anywhere water could be a problem, like basements, garages, or under sinks.

When water comes into contact with the probe, the transmitter relays the trouble signal. When you have a monitored water detection device, the transmitter will send that signal to a monitoring center, which can alert you that there is water present where it shouldn’t be. Then you can take quick action to help prevent costly water damage!

People also ask: Will water sensors stop a leak or a flood?

Pipe leaking water

No, a flood sensor will not stop a leak or flood in progress. Your flood detectors will instantly alert you in the event the sensor detects water.

8. Fire alarms / Smoke detectors

Use: Help protect against fire and smoke inhalation by detecting flames and abnormal levels of smoke. Some modern home fire and smoke alarm systems also include built-in heat detectors.

How do smoke detectors work?

Smoke detectors use two main kinds of technology: Ionization and photoelectric.

Ionization smoke detectors are better at detecting quick flash fires. They use a small amount of radioactive material between two plates. When smoke enters, it disrupts the ions and causes an alarm.

Photoelectric is better at detecting slow, smoldering fires that fill your home with smoke. Photoelectric uses a light source that’s angled away from the sensor. When smoke enters, it causes the light to reflect off the sensor, causing an alarm.

People also ask: What’s the benefit of photoelectric smoke detectors?

Photoelectric smoke detectors can help identify small fires that generate a lot of smoke early before they get out of control.

Get answers to more common questions about smoke detectors.

9. Carbon monoxide detector

Use: Detect carbon monoxide (CO) in your home, and help protect against carbon monoxide poisoning.

CO is a deadly, odorless gas that can come from any combustible appliance. Carbon monoxide alarm systems are specifically designed to detect gas particles using either a gel or silica chip. When the gas comes into contact with the chip, it prompts the sensor to send an alert.

People also ask: Why do I need a CO detector?

Because CO has no taste or smell, a detector is the only way to know if the poisonous gas is present in your home. Monitored carbon monoxide detectors can alert you to a gas leak and help you get assistance, even if you’re not home.

10. Lighting sensors

Use: Tell lights to turn off when a room is still and turn on when someone enters.

Smart home light control modules plug right into your existing outlets, letting you control the lighting in your home remotely. Using Z-Wave technology, these devices can work with your smart security system and other home automation devices for even more options and security measures.

Light control modules can also work in tandem with motion sensors to trigger lights to turn on when someone enters a room.

A row of townhomes with porch light sensors turned on

People also ask: Can I use smart lighting to save energy?

Yes! You can create custom lighting schedules for your personal routine, and even program lights to turn off when a room isn’t being used.

Bonus: Smart video cameras + Video doorbells

Use: Start recording and get alerts when important activity is detected.

Video security has come a long way in a short amount of time. For a while, home security video cameras just recorded raw footage nonstop, regardless of what is happening. If something did go wrong, a) no one would know about it and b) you would have to sift through hours of footage to find something amiss.

Today, most modern indoor and outdoor security cameras have a built-in sensor that tells them when to start recording. They may react to motion, noise, or even heat. Some even have object detection features that allow them to distinguish between a person, a vehicle, and an animal!

Learn more about smart video cameras.

Similar tech is available on home security doorbells as well, but you get to be even more selective about what you see. For example, the Video Doorbell Pro is focused on person detection. It can see the difference between a car passing by and the mail carrier dropping off a package — meaning less unwanted interruptions, and more moments that matter.

Wired versus wireless motion sensors?

Plain and simple, a wireless device functions without needing to be connected by wires into the walls of your home. More and more modern security devices are trending towards wireless, so this is where you’ll see the latest and greatest tech — that plays nicely with popular smart devices — coming on the scene.

Still, think about your home security system as one big integrated solution, rather than a collection of independent devices. If you already have a pre-wired security system, your devices may also be hardwired, and that’s totally fine! It’s also important to note that some devices labeled “wireless” still require a power source.

Always consult with your security provider before making any changes to your system or adding new devices.

What security sensors does my home need?

As you’ve probably guessed by now, this is a big question that is highly personal to your home, and your needs. Determining factors will include (but are not limited to):

  • How many doors and windows do you have?
  • Do you have kids?
  • Do you have pets?
  • Do you have a garage?
  • How many floors is your home?
  • Do you have a strong WiFi signal?

And so on.

Luckily, you’re not on your own. A reputable security expert can walk you through the decision-making process step by step and make highly informed recommendations. This is how you design the smart security solution of your dreams.

At Guardian Protection, we offer these consultations for free. Simply give us a call at 1.800.PROTECT (1.800.776.8328) to schedule an appointment!

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