Ultimate Guide to Home Security Equipment

Brianne Sandorf
Jan 06, 2021
Icon Time To Read16 min read

At a glance

If you just moved, you want to feel safe and settled in your new home—which is why having the best security system is so important. Even before you decide what the best security system is for you, though, it’s helpful to understand the many different pieces of equipment and what they actually do to ensure everyone’s safety.

To help you better understand your security system equipment in your new home, here is a list of all the essential pieces along with their definitions.

Top home security systems

Here's a table with the top home security company picks from the best home security systems reviews and which pieces each company offers.

Top 5 home security systems

Best for
Security System
Star Rating
Learn More
Best valueFrontpontFrontpoint
4.5 out of 5 stars
Starting at:
Most flexibleSimpliSafeSimpliSafe
4.3 out of 5 stars
Starting at:
Best DIYRingRing
4.2 out of 5 stars
Starting at:
Best self monitored optionAbodeAbode
3.7 out of 5 stars
Starting at:
Best customer serviceCoveCove
3.3 out of 5 stars
Starting at:

Data effective 12/13/2019. Offers and availability subject to change.

Home security equipment

Carbon monoxide detector

Carbon monoxide (CO) detectors alert you when there is a higher than safe presence of carbon monoxide in the air. According to First Alert, current UL Standard 2034 limits for CO alarms to sound are as follows:

  • 30ppm for 30 days
  • 150ppm for 10–50 minutes
  • 70ppm for 60–240 minutes
  • 400ppm for 4–15 minutes
Carbon monoxide

How carbon monoxide detectors work

A CO detector sounds an alarm if it detects a dangerous level of carbon monoxide. If you have a professionally monitored home security system connected to your COdetector, a monitoring center agent will be notified if your detector is ever triggered. This means you'll still be taken care of if you don’t hear the beeping from the detector because you’re not in the room or you’re asleep.

Types of carbon monoxide detectors

Different detectors are triggered by different sensors:

  • Biomimetic sensor: Gel changes color when CO is absorbed, triggering the alarm.
  • Electrochemical sensor: A chemical solution covers electrodes that sense electrical current changes when they come into contact with CO, which triggers the alarm.
  • Metal oxide semiconductor: The silica chip’s circuitry detects CO and the electrical resistance is lowered, which triggers the alarm.

Do I need a carbon monoxide detector?

You should have at least one CO detector in your home whether or not you have a security system. To be safe, you should have at least one on each floor.

What to do if your CO detector goes off?

If your CO detector sounds an alarm, you should evacuate your family immediately. Check each person for any flu-like symptoms. (This suggests poisoning.) If you notice these symptoms, call 911 immediately. Open as many doors and windows as possible as you and your family head outside. Do not reenter your home until the detector alarm stops, indicating that levels carbon monoxide have decreased to a safe range. Have your home evaluated by a professional so they can check all your fuel-burning appliances and other items that may emit CO. To get the best CO alarm, check out this best carbon monoxide comparison article.

Control panel 

What are control panels?

The control panel is the main component of your alarm system and is typically one of the first (if not the first) devices you set up for your security system. The control panel communicates with each sensor, camera, detector, etc., and sounds an alarm when a device is triggered. It then communicates with the monitoring station to alert the security company.

How control panels work

The control panel works in different ways depending on the type of monitoring you have (landline, broadband, or cellular), so the control panel needs to be connected to a phone jack, internet router, or cellular communication device.

Control panel

Different types of control panels

As we mentioned, the control panel can be a singular device or it can take the role of the keypad as well. If it is a single-use device, you’ll most likely place it hidden away from an entry point. If it is connected to the keypad you’ll probably still want it hidden but perhaps closer to an entry point so you can arm and disarm the system more easily.

Do I need a keypad for my control panel?

All security companies have a control panel but not all have a keypad. Most allow you to control the system from an app or key fob. So depending on the system you have, you may or may not need one.

For some systems, the keypad may be included with the panel. This is where you can enter your passcode to arm and disarm your system. You will most likely use the keypad on a daily basis since you’ll need to arm and disarm your system when you leave.

If your system has a landline connection and someone cuts your wires, you’ll lose connection to your system. In the case of a power outage, you could lose connection for your system if you have broadband. However, with a cellular panel, you are almost always covered, even if the power goes out or someone cuts your wires.

Door locks 

How door locks work

Door locks work by the use of a latch or bolt crossing the opening between the doorframe and door. There are two different types of bolts: spring bolt and deadbolt.

  • Spring bolt: These locks are held in place by springs and allows the doors to close (not reopen) when locked.
  • Deadbolt: This type of lock is more secure and stays in place until it is manually unlocked.

With both a spring bolt and a deadbolt, you lock and unlock the door by rotating the knob or key in a lock cylinder, which then moves the latch or bolt.

Types of door locks

There are various types of door locks, including electronic locks, smart locks, and traditional locks. Electronic door locks include a part called an actuator. The actuator connects the bolt or cylinder to a small motor, which allows the bolt to lock and unlock. A smart door lock is a great way to automate your home. Instead of using a key, you can use a card, keypad, or your phone as a remote to lock or unlock your door.

Door lock

For some door locks, you can be time zones away from your home, while others require you to be within a certain range. These are handy for when you have a housekeeper or dog sitter who needs access to your home. You can let them in from afar or grant them access through an app on their smartphone.

You can also schedule times for when your home is locked or unlocked (in case you forget), which can be handy for when you’ve left for work and can’t remember if you locked the house.

Many electronic locks still allow the use of a physical key as well, but these devices vary so be sure to research carefully if that is something you’d like.

Traditional locks are locked by hand. This is done by entering a key and turning it or turning a lock button.

Door/window sensors

What door/window sensors do

door window sensor

If an intruder enters your home by opening a window or door and your system is alarmed, the door/window sensor will send a signal to the control panel that it has been triggered, alerting you and the central monitoring station.

How door/window sensors work

Door and window sensors come in two pieces: one piece that sticks to the door/window frame and one that sticks to the door or window. These two pieces are installed adjacent to one another and when the door or window is closed, the sensor pieces are joined together. The two pieces have a magnetic connection that, if broken, causes the sensor to communicate with the control panel to notify it that a sensor has been triggered.

Types of door/window sensors

For the most part, door and window sensors are pretty much the same from company to company. The only difference is sometimes companies offer door sensors and window sensors individually, or contact sensors which can be used for both doors and windows. If they are sold individually as door and window sensors, then the door sensors are most likely a little larger than the window sensors, but they work the same way.

Do I need a door/window sensor?

These are typically best used on doors than windows since windows are commonly smashed. If your windows are normally locked, we suggest getting door sensors and glass break sensors.

Doorbell camera

Types of doorbell cameras

A doorbell that is connected to your home security system can notify you when someone is at your front step. Some doorbells have built-in cameras and with others, you can install a camera above to see who’s at your door.

Some have motion detection to notify you when someone is within range. When someone presses your doorbell (or is detected within range) you will receive an alert on your phone. If there’s a camera, you’ll be able to see who is there. And if your doorbell has two-way voice, you can even talk to them. So if the delivery person has a package for you, you can tell them to leave the package on your doorstep.

Doorbell camera

Do I need a doorbell camera?

A smart doorbell is an optional component to your home security system. If you prefer having this smart feature, we say go for it. Currently, Vivint is the only company in our top 10 with a smart doorbell, and Link Interactive has a smart doorbell, but it does not have a camera built in.

Other companies offer outdoor security cameras that can be placed by your front door, but no others offer an actual doorbell. You can also take a look at our list of the best doorbell cameras currently on the market.

Fire/heat/smoke detector

What fire/heat/smoke detectors do

Fire alarms typically include smoke and heat detectors in them. So for the sake of this article, we are going to include them into one. However, please note that this is not always the case and it’s important to check your equipment to see what it detects and senses. As the name suggests, these detectors sense fire, heat and smoke.

How fire/heat/smoke detectors work

Security companies are now including fire detectors as a way to automate your home. These are connected to your system to notify you and the monitoring station when heat, smoke, or fire is sensed.

FIre detector

Types of fire/heat/smoke detectors

There are three types of fire alarms: ionization, photoelectric, and dual sensor. We cover all of these in this best smoke detector article.

  • Ionization fire alarms create an electric current between two metal plates. When smoke enters the chamber, an alarm sounds.
  • Photoelectric fire sensors have a light source in an electric sensor positioned at 90-degree angles. When light enters, it normally misses the sensor. However, when smoke enters the chamber, the light scatters and triggers the alarm.
  • Dual sensor fire detectors include elements from both ionization and photoelectric sensors.

Flood sensor

How flood sensors work

If excess water is detected, an alert is sent to the monitoring station (or you) that there may be a flood.

Types of flood sensors

For the most part, flood sensors are all the same. They alert you in the case of excess water in your home where that sensor is located.

Flood sensor

Do I need a flood sensor?

While a flood sensor isn’t a must, it’s definitely suggested. Flood sensors are typically placed near water heaters since this is the most common place for a flood to occur. These sensors are also placed inside or next to basement sump pumps. That way, you are alerted about the issue before the water reaches your basement and floods it. They are also sometimes placed behind washing machines in case a hose breaks.

Freeze sensor

What freeze sensors do

A freeze sensor, or low temperature sensor, detects when temperatures approach freezing. This can help keep your pipes or other parts of your home from freezing and can alert you to an improperly functioning furnace.

How freeze sensors work 

Many freeze sensors use negative temperature coefficient (NTC) thermistors. Thermistor is a combination of the words thermal and resistor. The NTC thermistor helps determine the temperature reading. This is an important part of the freeze sensor. The trigger temperature can vary, but typically it’s around 41 degrees Fahrenheit.

Types of freeze sensors

Some freeze sensors are made for indoor use only, while others can be used outdoors. Be sure to check the flood sensor before you purchase it so you know where to place it.

Freeze sensor

Do I need a freeze sensor?

Freeze sensors are great for vacation homes and can save you thousands of dollars in damages. They can also be used in climate-controlled rooms that have important objects in them. So if you have a home you are away from frequently or a room with valuables that need to be temperature controlled, you should get a freeze sensor.

Smart garage controller

Garage controller

A garage controller is like a door/window sensor but it’s for your garage. You receive an alert when your garage door is triggered. This is great for those days you’re in a hurry to get out the door and you panic that you forgot to close the garage door. Typically you’ll get an alert that you left your garage door open and you can close it with the push of a button.

What smart garage controllers do

A garage controller allows you to open and close your garage door from your security company’s app.

How smart garage controllers work

All you have to do is log in to your app and press the open or close button. It works similarly to a smart door lock because they both use a phone to lock or unlock, or in this case, open or close the garage door.

Types of smart garage controllers

The equipment is similar to a normal garage controller where you have the remote clipped onto your visor. Install a device onto your garage door and that’s it.

Do I need a smart garage controller?

These aren’t absolutely necessary, but they can be very handy.

Glass break sensor

What glass break sensors do

Glass break sensors detect when glass is broken, specifically from your windows.

How glass break sensors work

A glass break sensor detects the vibration and specific sound frequency generated when glass breaks. These sensors are armed even when your system is set to Home mode. So keep in mind that if you ever drop a glass you may trigger an alarm. The typical range for these sensors is 20 feet, so one sensor can cover a lot of ground. However, doors and walls can decrease the sensitivity of these sensors.

Glass break sensor

Types of glass break sensors

Glass break sensors are typically installed on the opposite/adjacent wall from windows or on the ceiling. Be sure to check the range for your sensor so you install it close enough to the windows.

Do I need a glass break sensor?

Glass break sensors are an important component of your security system because if a burglar breaks through a window the window sensor most likely won’t trigger it since the sensor wasn’t pulled apart. However, a glass break sensor would sense this and immediately alert you and the monitoring station. So if you’re trying to choose between a window sensor or a glass break sensor, consider a glass break sensor.

Image sensor

What image sensors do

When an image sensor senses motion it takes a snapshot of the view and alerts the monitoring center or sets off the alarm.

How image sensors work

An image sensor is a motion sensor with a camera built into it. If a subject passes the image sensor within range, the image sensor takes a photo of the view.

Image sensor

Types of image sensors

Some image sensors are pet-friendly so they won’t snap photos of your dog roaming throughout the house. However, this can depend on the weight of your dog. So if you have a bigger dog, it may trigger the image sensor.

Do I need an image sensor?

Image sensors can reduce the number of door/window sensors you need, which are common components to a home security system. So if you have a space with four windows, it may be more cost effective to purchase one image sensor instead of four window sensors.

Indoor camera

What indoor cameras do

Indoor cameras are meant to be used inside to record any activity in your home. They typically are not weatherproof, so if you place it outside, the camera may get damaged.

How indoor cameras work

Most indoor cameras need to be plugged in to a power outlet to work. This can limit where you are able to locate the camera. Fortunately, most indoor cameras don’t have to be wired back to the control panel so you don’t have to worry about that.

But if you want to have the camera positioned on a wall, perhaps in the corner of a room, you may need to place a couple screws in the wall. Keep in mind the length of your power cord when you do this.

Indoor camera

Types of indoor cameras

Some features you’ll want to take into consideration are night vision, field of view, audio capabilities, pan/zoom/tilt, and video resolution. If your camera doesn’t have night vision it will be useless in the dark, so night vision is a must.

If you have a large room but the field of view is only 45 degrees and there are no pan/zoom/tilt capabilities, you’ll probably need another camera or two to monitor the entire room.

Common places for indoor cameras include living rooms, offices, and garages. They typically don’t record footage 24/7, only when motion is detected.

Many companies have the ability to let you view your camera’s footage through their app so you can check on your home while you're away.

Do I need an indoor camera?

Indoor cameras give you valuable insight into your home. If someone breaks in, a camera can capture footage that you can turn over to the authorities to help catch the culprit. They can also let you check on loved ones at home while you're away, or to just see if everything's fine while you're on vacation. An indoor camera is certainly useful, but it's not necessarily an integral part of the home security system.

Key fob

What key fobs do

A key fob (also called a keychain remote) is like the remote control you use to lock and unlock your car except it’s used to alarm and disarm your system.

How key fobs work

The key fob for your security system also has a panic button that sounds a loud siren to alert the monitoring company that there’s an emergency. There is also a home button which sets your alarm to Home mode, meaning the system is armed but only for entry sensors (door/window sensors). So if a door or window is opened, you are alerted. The range on these devices can be up to 500 feet.

Different types of key fobs

Most key fobs are the same and have four buttons: arm, disarm, home, and panic.

Keychain remote

Do I need a key fob?

We recommend having a key fob because it helps you alarm and disarm your system. Many home security systems come with two key fobs and oftentimes you can add another key fob to your system so multiple family members can each have one.

Lights & small appliance controller

What lights & small appliance controllers do

These are commonly called smart switches, which allow you to turn small appliances or lights on and off remotely through an app.

How lights & small appliance controllers work

light control

If you connect a controller to a light you can turn the light on and off from afar. If it’s connected to a slow cooker, you can turn it on a couple hours into your work day so your dinner is ready when you get home. Be sure to have your actual appliance turned on because if the appliance is set to off and you turn the switch on, it won’t flip the appliance switch to on for you.

Types of lights & small appliance controllers

Most smart switches are the same. You plug the smart switch into a power outlet and then plug your light or small appliance into the smart switch. Then from your app you can turn the switch on and off.

Types of lights & small appliance controllers

A smart switch is not a necessity, but if you travel often, we recommend them. The controller will allow you to connect a light to the switch and turn it on and off remotely so it looks like someone is inside your house.

Motion detector/sensor

What motion detectors/sensors do

A motion detector does exactly that—it detects motion. It’s one of the basic components to a home security system so most security systems have motion sensors in their equipment lists.

How motion detectors/sensors work 

Motion detectors/sensors protect an area of your home by creating a space that cannot be entered without an alarm being triggered. So if someone (or sometimes even a pet) enters the zone, the motion sensor will alert the control panel. Motion sensors are often used in rooms that contain lots of valuables (e.g., living rooms, offices, etc.).

If someone entered your home through a door or window that didn’t have a sensor on it, the motion detector could still pick up the activity (if the intruder walked through the monitored area).

motion detector

Types of motion detectors/sensors

The degree angle and distance can vary with each motion detector/sensor, so it’s important that you check yours specifically so you know what area your sensor can monitor. Most companies that have motion sensors allow them to be placed on a flat surface or mounted on the wall (either by screws or a heavy-duty sticker). The sensors are typically wireless.

Do I need a motion sensor?

You should have at least one motion sensor in your home. When you’re placing your motion sensor you’ll want to be careful. Some pets trigger motion detectors so check with your company to see if there is a size limit.

Try to avoid placing motion sensors by windows. Light from the sun’s movement throughout the day could trigger your sensor causing a false alarm (this has happened to me before!).

Outdoor camera

What outdoor cameras do

An outdoor security camera helps surveil your property and alerts you when someone has trespassed.

How outdoor cameras work

Most outdoor cameras for homes record footage only when motion is detected. However, some record footage 24/7.

Types of outdoor cameras

Outdoor cameras are most often wired but sometimes are wireless. Some features you’ll want to take into consideration when choosing an outdoor camera are night vision, field of view, weather resistance, color vs. black and white, audio capabilities, pan/zoom features, and video resolution.

One of the benefits of using an outdoor camera is that many times you can access the footage remotely on an internet-enabled device (depending on the camera). They’re great for when you’re out of town and want to check in on things or when you’re at work and want to watch for a delivery or a service person.

Outdoor cameras are often used near garages, entrances to a home, and backyards.

Panic pendant

What panic pendants do

To use it, push the button on the pendant, which will then send a signal to the monitoring station. A professional will be in touch with you to see what type of assistance you need. The proper authorities will be notified and you will have help shortly after.

Types of panic pendants

It is a small, battery-operated device similar to a key fob. Ideally, the pendant is waterproof so it can be worn in the shower since many falls occur in the bathroom.

Panic pendant

Do I need a panic pendant?

These are commonly recommended for people who are at risk of falling. If you think this would make you feel more comfortable, a panic pendent is definitely or you.

Recessed door sensor

What recessed door sensors do

A recessed door sensor is like a regular door sensor, but it’s less noticeable.

How recessed door sensors work

door window sensor

Recessed door sensors consist of two pieces: one placed directly inside your door or window and the other placed inside the frame. When these two pieces separate you are notified, or the central monitoring station is notified.

Types of recessed door sensors

Most companies require that your door or window, as well as the frame, be made out of wood so you can drill easily. Since the equipment is hidden in the frame it is less noticeable to a criminal. Door and window sensors are bulkier and can easily be seen; recessed door sensors fit inside the door/window so they blend in easily.

Do I need a recessed door sensor?

Recessed door sensors are inconspicuous and typically have good battery lives. Although this does require some drilling, they still tend to be better than regular door sensors.

Smart thermostat

Smart thermostats help you cut your electric bill and help you be more energy efficient. Depending on the thermostat you purchase, it can learn your routine and automatically change the temperature to your preference. Most allow you to change the thermostat from a smartphone app so you can adjust the temperature before you leave work or when you’re on your way back from vacation.

What smart thermostats do

Thermostats allow you to regulate the temperature in your home.

How smart thermostats work

Thermostats turn your heating or air conditioning on and off to keep your home warm or cool.

Types of smart thermostats

Some allow you to set schedules while others require you to adjust as needed manually. The Nest thermostat is a smart thermostat that can learn your schedule and automatically adjusts to your preferences after learning your behaviors.

Many security companies offer thermostats as a home automation feature. You can control the thermostat from your app and adjust the temperature as needed.

Do I need a smart thermostat?

You most likely already have a thermostat, but if you want to save on your energy bill, purchasing a smart thermostat is a good decision.

Tilt sensor

What tilt sensors do

The tilt sensor monitors an object and makes sure it is kept stationary.

How tilt sensors work

Tilt sensors are commonly used on overhead garage doors. They can also be used on windows that tilt, hatches, sheds, or other objects that shouldn’t be moved. When the object is moved the sensor moves as well, which then sends a distress signal to you or the monitoring station.

Types of tilt sensors

Most tilt sensors are the same. When an object with a tilt sensor is moved, that movement alarms the sensor.

Do I need a tilt sensor?

Tilt sensors are important to put on garages and sheds. These are two areas that people often forget to secure. If a burglar breaks in through your garage door they’ll get into your home in no time. However, if you have a tilt sensor you’ll be notified immediately and will be able to send authorities to your home for help.

Recommended resources

A home security system is one of the smartest investments you make for your new home. A lot that goes into picking the one that gives you and your loved ones the most peace of mind. Still need help deciding the best security system for your home? Take a look at some of the highest rated and most affordable systems out there:

Brianne Sandorf
Written by
Brianne Sandorf
Brianne has a degree in English and creative writing from Westminster College and has spent 5+ years writing professional, research-based content. Before joining Reviews.org, she wrote for ASecureLife.com. Her pieces and quotes are published across the web, including on Stanford's student blog and Parents.com. Hobbies include wearing a seatbelt, wearing a life jacket, and keeping her arms and legs inside the ride at all times. Contact her at brianne@reviews.org.