The main purpose of a home security system is to keep your property and the people inside it safer. Harm may come in the form of a burglary, home invasion, fire, flood, or other environmental disaster. Most home security systems can monitor for all of these. These systems use a combination of sensors that communicate over radio frequencies or wires to a central hub, which then communicates with the outside world using a cellular connection or occasionally a landline. The hub is generally a touch screen mounted to your wall or a small box placed on a counter or in a cupboard.
The sensors are installed strategically around your home at entry points such as doors and first-floor windows, as well as in hallways and high-traffic areas. They detect when a door or window is opened or closed, when someone is moving around in your home, or both. When the system is armed, it sends an alert to the hub after a sensor is triggered. The hub then sounds an audible alarm, sends you a notification (a phone call, text, or a notification on a mobile app), and can alert a monitoring center if you have professional monitoring.
With professional monitoring, trained security company employees track the signals from your system and attempt to contact you and the relevant authorities if a potential threat is detected. All professionally installed security systems require professional monitoring contracts for up to three years. Most DIY systems give you the choice of using professional monitoring with no long-term commitment.
Today, most home security systems are wireless and don't require a landline or electrical work to install. Here is a rundown of the common security alarm features and what each one does:
Control panel or hub
This is the heart of a security system. It uses radio signals to communicate with your security sensors, you, and the monitoring center. Most feature a built-in keypad or another way to manually arm and disarm the system.
Key fob and/or keypad
These are additional ways to arm or disarm the system. Often a keypad is built into the system's hub, but you can buy additional keypads, which can be helpful if you have more than one exterior door. With a wireless smart system, you can also use an app on your smartphone to manage the alarm.
Contact sensors
These are small, plastic, battery-powered devices consisting of a sensor and a magnet. You place the sensor on one part of a door or window and the magnet on the other. When the door or window opens, the contact between them breaks and a signal is sent to the hub.
Motion sensors
These slightly larger plastic, battery-powered devices are generally placed up high to cover areas people have to move through when they're in your home. These mainly use a technology called passive infrared that detects movement by sensing body heat.
Glass-break sensors
A glass-break sensor listens for the sound of broken glass and generally has a range of about 25 feet. They're a good option in homes with large pets who may trigger motion sensors. Because a contact sensor can be bypassed if a burglar shatters a window and then climbs through to gain access into your home, a glass-break sensor is a good secondary measure for windows and sliding glass doors.
High-decibel sirens
While today's wireless technologies provide many sophisticated ways to scare off burglars, there's nothing better than a good old-fashioned piercing alarm to alert you and your neighbors to potential danger. All home security systems offer an interior siren. Most are built into the hub, and many have the option of adding an external siren. Generally, these emit a noise somewhere between 80 and 115 decibels.
Yard sign and stickers
Brightly colored signs advertising your home security system are standard equipment and are your first line of defense. Many burglars won't even attempt to break in when they see them. Professor Joe Kuhns of the Department of Criminal Justice and Criminology at UNC Charlotte conducted a study among incarcerated burglars to find out what motivates and deters them. "The burglars themselves suggested to us that if they saw indications of an alarm system, whether that's a sign or a visible camera, they would simply go elsewhere," Kuhns says.
Cameras
Many home security systems don't come with surveillance cameras, but they are the most popular add-on, say security company representatives we spoke with. Video doorbell cameras are the most common type. These can connect to your home security system with your existing doorbell wiring or wirelessly over Wi-Fi and alert you when they detect motion at your front door. Some doorbell cameras can even detect when a package is dropped off. Weatherproof outdoor cameras are also popular. These either plug into an outdoor socket or are routed to an indoor socket, which usually requires drilling a hole through a wall. Some outdoor cameras are battery-powered, and some even have solar panels so they don't need to be charged. Indoor cameras are found in many home security systems as well, although they're somewhat less popular due to privacy concerns.
Regardless of where they're placed, most security cameras can detect motion and send alerts. Some cameras can detect people specifically, and a few even have facial recognition. Cameras either record video continuously, or only when they detect motion to save storage space. Video is stored locally on a hard drive or in the cloud for a monthly fee.
Environmental sensors
Sensors that detect smoke, heat, carbon monoxide, water, and temperature can protect you and your home from fire, frozen pipes, and gas poisoning. These sensors don't come standard with most security systems, however. Some DIY systems don't offer professional monitoring of environmental sensors, so be sure to check if this is something you want.
[ SEE: Best Home Security Systems ]
Do Home Security Systems Work?
Installing a home security system has been proven to reduce the likelihood of your property being burglarized. A study by Rutgers University School of Criminal Justice that analyzed crime data from the Newark Police Department over a four-year period showed that burglaries in Newark decreased as more security systems were installed. "The study credits the alarms with the decrease in burglaries and the city's overall crime rate," study author Dr. Seungmug Lee said in a press release. The study also said that technical improvements in home security systems, such as modern sensors and better signaling technology, have made them more dependable.
"It can't hurt to have a security system installed, whether it's DIY or not," Kuhns says. "It's one measure of prevention that our research shows has some impact on some offenders."
"It can't hurt to have a security system installed, whether it's DIY or not," Kuhns says. "It's one measure of prevention that our research shows has some impact on some offenders. It doesn't mean you're not going to get burglarized ever, but if given a choice and if you're concerned about safety it can't hurt to have a burglar alarm system." His study concluded that 60% of burglars were deterred by the presence of an alarm, and that most burglars would look and see if an alarm was present before trying to break in. Moreover, half of those would give up if they found an alarm during their attempt to break in. Reaching similar conclusions, the National Council for Home Safety and Security, a trade association, says that homes without a security system are 300% more likely to be burglarized. Despite these statistics, according to data from Parks Associates, relatively few U.S. households with broadband internet have a professionally monitored home security system.
What Are the Pros and Cons of DIY and Pro-Installed Home Security Systems?
Once you've decided to take the plunge, how do you choose between a professionally installed system and a DIY system? Price is a primary reason people choose DIY over professionally installed. But what do you lose by not paying for an installer? According to Paul Rothman, editor-in-chief of Security Business, a magazine covering the professional security industry in partnership with SecurityInfoWatch.com, you are giving up important expertise. "There is a right way and a wrong way to hang a camera or position a motion sensor inside a home," he says. "Professional installers understand how to do this, but it is not so easy for many consumers." Additionally, he points out that a professional can make sure everything in the home actually works together "instead of a bunch of equipment with different apps and control functions." The advantage of a DIY system, however, is that you can choose to self-monitor �C something no pro-install company offers �C and not be tied into paying monthly fees.
