Fire Alarms vs. Smoke Detectors vs. Smart Smoke and Heat Sensors

For many families, smoke alarms are all that stand between their home and escaping a fire. But while unmonitored smoke detectors can effectively alert homeowners to fires if they’re home to hear them go off, they become just noisemakers if the house is empty when the fire breaks out—or worse, someone is home but unable to escape or call for help.

Fortunately, smart technology is changing the fire protection game. Intelligent smoke and heat sensors allow homeowners to catch home fires early and almost immediately get help—even if no one is home to hear the alarm.

Many people assume that home fire detection devices are interchangeable with each other, but there are important distinctions between them. Let’s dig into the differences between smart smoke and heat sensors, smoke detectors, and fire alarms to help you select the right components to keep your home and loved ones safe from fire.

In 2017, a home fire occurred every 88 seconds in the U.S. Nearly 380,000 home fires caused $7.9 billion in property losses, more than 2,700 deaths, and almost 11,000 injuries.

Your chances of dying in a home fire is more than twice as high if your home lacks working smoke alarms, with three out of five home fire deaths occurring in residences without them, according to the National Fire Protection Association (NFPA). As synthetic modern furnishings cause fires to spread more rapidly than ever before, NFPA warns that having enough smoke alarms is essential to maximizing the amount of time you and your loved ones have to escape a blaze.

At a minimum, NFPA recommends smoke alarms installed inside every sleeping room, outside every sleeping area, and on every level of a home. Additional alarms are required for large residences.

But what, exactly, is a “smoke alarm?” There are actually several options for detecting smoke and fire in a home:

Home smoke detectors are smoke-sensing devices that trigger a loud, piercing alarm when an abundance of smoke particles are in the air. A small minority of smoke detectors also activate fire alarms linked to a monitoring service or the fire department, and many come with flashing lights to alert the hearing impaired to the danger. The vast majority, however, just make noise.

Generally, home smoke detectors work in one of three ways:

• Ionization detectors respond best to fast, raging fires and flames. They use a small amount of radioactive material passing between two electrically charged plates to create an ionization chamber. This ionizes the air and creates a current that flows between the plates. Smoke particles disrupt the flow of ions, reducing the current and triggering the alarm.
• Photoelectric detectors respond best to smoky fires that start with a long period of smoldering. They rely on a photoelectric sensor and a light source to detect smoke. When smoke seeps into a compartment in the detector, it covers the light beam and reflects light onto the light sensor, causing the alarm to sound.
• Dual sensor detectors contain both photoelectric and ionization technology, thus providing a broader spectrum of detection.

But here’s the thing: since most home smoke detectors don’t link to monitored fire alarms (as they do in many commercial buildings), they only serve as an immediate warning to people inside the house. If you’re not home to hear an unmonitored detector go off, you will remain blissfully unaware of the danger and fail to protect your property. And in very large homes, unmonitored smoke alarms may not be loud enough to alert people in other parts of the house to the fire.

Of course, unmonitored smoke detectors also won’t help loved ones who can’t move outside or call for help on their own, such as infants, the elderly, pets, or people who become overwhelmed by smoke. And smoke inhalation is the leading cause of death in house fires.

One key thing to keep in mind about smoke detectors: They should be replaced 10 years after the date they were manufactured, as they become less sensitive over time. To check how old a detector is, remove it from the ceiling and look on the back for the manufacture date. If it’s time to replace, there is an upgrade to consider …

Smart smoke and heat sensors take home fire protection to another level. They link to your home security system, enabling you or your monitoring service (in monitored systems) to quickly notify the fire department in the event of a blaze. Unlike some of the overall security system’s intrusion detection features, smart smoke and heat sensors do not need to be “armed”—they work around the clock to protect people and property.

These wireless sensors also trigger instant notifications to your smartphone if they sense something amiss, specifying the name of the device reporting a problem. If you are at work or on vacation, you can quickly check to see if there is a real emergency. Smart smoke and heat sensors that are part of a smart security system enable absent homeowners to visually check on their homes through real-time video from indoor security cameras. The system also allows homeowners to silence the alarm from their smartphones if no danger is apparent, which also informs the monitoring service that an event is a non-emergency and stops them from dispatching the fire department.

Incidentally, that remote silencing feature can come in handy if smoke and heat sensors are accidentally triggered while you’re home. This feature is appreciated by anyone who has struggled to silence a blaring smoke detector on the ceiling by jabbing its button with a broomstick.

If a system is professionally monitored instead of self-monitored, it provides even greater protection. For example, if you have a Frontpoint-monitored system, personnel will call you to verify the emergency when a smoke and heat sensor is triggered. If there is no answer or an incorrect passcode is provided, emergency services will be dispatched to your home immediately—providing 24-hour protection, seven days per week—whether you are away, sleeping, injured, or otherwise indisposed.

Homeowners can also receive push notifications when a sensor’s batteries are low through the smart security system’s app as well as if a sensor goes completely offline—ensuring continuous protection and avoiding that torturous chirping that traditional smoke detectors seem to only emit in the middle of the night. These sensors work in tandem with other smart security system features as well; for instance, the system can automatically turn on smart lights when smoke and heat sensors sound to illuminate escape routes and help homeowners identify the problem.

Smart smoke and heat sensors rely on the same smoke-detecting technologies as standard smoke detectors but can also sense when the temperature of a room gets too hot, too fast. Frontpoint Security’s Smoke and Heat Sensors rely on three fire protection technologies:

• Smoke detection that sounds an alarm if they sense an abundance of smoke particles in the air.
• Fixed temperature sensors that trigger an alarm once a certain temperature has been reached; typically, 135°
• “Rate of rise” temperature sensors that set off the alarm if they measure an unusual and dangerous increase in room temperature of more than 15°F within 60 seconds.

A related life safety feature that can be tied into smart security systems are carbon monoxide sensors, which detect dangerous levels of carbon monoxide in a room. Some sensors can also be set to give a “pre-alarm” warning for dangerous levels of the poisonous gas. Although toxic levels of carbon monoxide can be present in a home for other reasons, the invisible, odorless gas is readily generated from the combustion of wood and other cellulosic materials.

“Fire alarm” is often used as a catch-all term that people use to describe smoke detectors or basically anything that emits noise and/or notifies people of a potential fire. But more specifically, a typical “fire alarm system” is more complex and usually seen in commercial structures.

These more complex commercial fire alarm systems are typically found in businesses and multi-unit residential properties rather than single-family homes, and they have different requirements based on the structure’s occupancy type. They may be activated manually or automatically tied to various initiation devices like smoke detectors. These systems blast a bell, siren, and/or voice notification that warns people to exit the building before a fire reaches a dangerous size. Many feature strobe or flashing lights to alert the hearing impaired. Fire alarms may also automatically transmit signals to a central monitoring station or the fire department.

A commercial fire alarm is sometimes part of an active fire protection system that networks with all of the detection and protective components in a building. It can be comprised of and integrated with alarm-initiating devices like smoke detectors, internal-notification appliances like sirens, fire-suppression units like sprinkler systems, and power supplies. These systems can be wired or wireless and may feature manual pull stations that trigger the alarm.

Again, they are typically found in commercial properties because of government code requirements, their expense, and their intricacy. Commercial alarms generally require professional technicians to install and maintain them. In contrast, traditional smoke detectors or smart wireless smoke and heat sensors are simple for homeowners to install and maintain on their own. And the latter offers much of the integration possibilities and control that are seen in commercial fire alarm systems—without the expense and complexity.

Once you select fire detection equipment for your home, proper placement is key to achieving the best protection. Here are some simple tips to help you determine the most effective placement for your smoke and/or heat detection devices:

• The higher, the better. Since smoke and heat rise, the ideal place for detection equipment is on the ceiling. If that’s not possible, a high point on the wall can work as well. Equipment must be at least 4 inches away from corners where the wall and ceiling meet. It should also be kept at least a foot below the pinnacle of pitched ceilings.
• Multiple sensors are important. Once again, NFPA recommends that homeowners install smoke-detection equipment inside every bedroom, outside each sleeping area, and on every level. A single sensor won’t provide adequate protection for the average single-family home.
• Avoid places likely to trigger false alarms. Smoke detectors and smoke and heat sensors can be placed virtually anywhere, but there are some places that are better to avoid. The kitchen is a poor choice for installing smoke-sensing equipment, as cooking may set off an alarm. Bathrooms should also be avoided, as steam can be misinterpreted as smoke in some detectors. Rooms with fireplaces, however, are fair game—as long as the sensor isn’t located close enough for heat to trigger a combination smoke and heat sensor.

Alarms act as the first line of defense when a fire breaks out in a home—giving people time to remove themselves and their loved ones from danger. But unmonitored smoke detectors are useless if no one is home to heed their warning—or the people and pets inside can’t call for help or escape on their own.

And commercial fire alarm systems, while incredibly effective, are typically too complex and expensive for homes. Smart smoke and heat sensors paired with smart home security systems offer homeowners much of the functionality of more complex commercial systems—and greater peace of mind and control than traditional smoke detectors alone.

Frontpoint keeps families safer and more connected in their everyday lives. We've been revolutionizing the home security industry for over a decade. And we're just getting started. To shop DIY home security systems, check out our Security Packages. If you have questions or would like to discuss a quote, contact us at 1-877-602-5276.