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Best Smoke Alarms 2018 – [Buyer’s Guide]Last Updated February 1, 2018
Best Smoke Alarms of 2018
However, after giving you the TOP list, I will also give you some of the benefits you stand to gains for using it. There’s a product for every kind of user on the list of affordable options below.
I browse the various smoke alarms available on the market and list three of the very best. You must have heard that the best smoke alarms should allow you to save money, right? Sure, but that’s not the only reason you should consider getting one.
Test Results and Ratings
Why did this smoke alarms win the first place?
The product is very strong. Its material is stable and doesn’t crack. I really enjoy the design. It is compact, comfortable and reliable. And it looks amazing! I am very happy with the purchase. It is definitely worth its money. The product is top-notch! I also liked the delivery service that was fast and quick to react. It was delivered on the third day.
Why did this smoke alarms come in second place?
This is a pretty decent product that perfectly fitted the interior of our office. I really liked it. It is amazing in every aspect. It did even exceed my expectations for a bit, considering the affordable price. I recommend you to consider buying this model, it definitely worth its money. Seems that the material is good. It has a very beautiful color but I don’t really like the texture.
Why did this smoke alarms take third place?
A very convenient model. It is affordable and made of high-quality materials. I liked the design. We’ve been using it for 2 months and it still looks like brand new. It is inconvenient to use due to the size. I am going to get something different next time. It doesn’t squeaks nor bents. Looks great in my apartment.
Smoke Alarms Buyer’s Guide
The similarities between the following smoke safety devices start and end with one main function — when your smoke alarm sounds, you’ll get a push notification to your phone, whether you’re home or away. How they do this, what else they do, how much they cost and how many smoke alarms you can cover with a single device vary widely from category to category, and even within the categories themselves.
Here are the different types of devices you can use to alert you from afar when your smoke detector sounds.
1) Smart smoke detectors: The most obvious way to add smarts to your smoke detectors is to replace the device itself with an internet-connected version. Led in popularity by the
Nest Protect, your choices include models from First Alert, Halo Smart Labs and Roost. More options are on the way from Birdi and Netatmo.
Since none of these devices talk directly to your smoke detectors, you won’t get any help mitigating annoyances like false alarms or low battery chirps. You’ll start to see the cost advantages of a listener if you have a big home and you want complete connected coverage, as a single device can cover upwards of a floor of your home. So instead of having to replace the smoke detector in every bedroom, you can put one listener in the hallway and be done with it.
The Roost seems like a less permanent solution than the other two categories, but most smoke detectors are only rated to last for years. You’ll have to put a Roost into every smoke detector for complete coverage, so it’s not as efficient at comprehensive smarts as a listener, but it’s a more cost-effective route than wholesale replacement and neutralizes more inconveniences than listeners.
Every year the fire and rescue service is called to over 600,000 fires which result in over 800 deaths and over 17,000 injuries. About 50,000 (140 a day) of these are in the home and kill nearly 500 and injure over 11,000, many which could have been prevented if people had an early warning and were able to get out in time. In fact you are twice as likely to die in a house fire that has no smoke alarm than a house that does.
Buying a smoke alarm could help save your home and the lives of you and your family.
Who this is for
Among all the smart-home devices available today, a smart smoke alarm is probably the most important and the one that even smart-home skeptics should consider. The primary task of any smoke alarm, smart or not, is alerting you to potential danger. A smart alarm will do so even when you’re not home, and for most people, that should make such an alarm worth the price. Whether you’re across the street or across the country, a smart alarm will let you know (via your smartphone) when it detects smoke in your home.
Among all the smart-home devices available today, a smart smoke alarm is probably the most important and the one that even smart-home skeptics should consider.
Another benefit of smart smoke alarms over standard ones is that you can more easily tell when they’re not working. Manufacturers and fire-safety experts say you should manually test your alarms once a month and replace the batteries twice a year (at the same time you change your clocks). Smoke alarms are either battery-powered or hardwired (meaning you can install that kind only where the house has wiring to support it), but even hardwired alarms have batteries in them in case the power goes out. Smart alarms can periodically test themselves or allow you to test them remotely through their companion app, and some have batteries that last five to years, helping to make sure you have working alarms in your home.
One of the biggest problems with regular smoke alarms is that too often they stop working, either because a sensor died or because the device lost a fight with a broom handle when you couldn’t reach the silence button. Some smart alarms also let you silence “nuisance” alarms through the app on your phone (rather than pulling the battery out), meaning you’re a lot less likely to end up with a nonworking alarm in your home. It bears repeating: According to a 201report, almost a quarter of all home-fire-related deaths in the United States from 200through 201occurred in homes with nonfunctioning smoke alarms
If you already need to replace your smoke alarms anyway—fire-safety experts recommend doing so every years because sensors wear out—we think the price premium for going smart, while not insignificant, is a small one to pay for added peace of mind. This is especially true if you already have other smart-home equipment such as cameras, which allow you to confirm whether something has actually gone awry in your home when an alarm goes off.
How we picked
We looked at both battery-powered and hardwired alarms, and we evaluated their wireless interconnectivity features. Photo: Jennifer Pattison Tuohy
A smart smoke alarm should alert you on your smartphone when it senses smoke, as well as tell you which room is in danger; it should also include intelligent low-battery alerts and remain easy to silence safely from the app. Some other features worth having include voice alerts, self-testing and reporting, and the ability to reach an emergency-contact person automatically if you don’t respond.
Most important, an alarm should connect wirelessly with other alarms in the home, or come in a hardwired version that you can wire to other alarms, so that when one alarm senses danger all alarms in the house will sound. This is a crucial safety feature that can save you precious seconds in evacuating your home. Also, many states now require interconnected alarms for new construction, so if you do a significant remodel in your home, you don’t want to end up having to buy a different brand of alarm for the new area (most brands don’t play well with one another when it comes to interconnected alerts).
Although this review primarily focuses on the smart-home features of smoke alarms, it’s of course important that they do their primary job well, and that is to detect potentially life-threatening situations in your home. Because your safety is at stake, for us to even consider a smoke alarm for testing, it had to meet UL standards for smoke and carbon monoxide (CO) detection. UL (formerly Underwriters Laboratories) is a safety consulting and certification company that has been keeping Americans safe for more than 100 years by drafting standards for the electrical devices and components people use every day. UL tests all smoke alarms, smart or not, by the same standard, simulating both fast-burning and smoldering fires, so you can feel confident that certified technology will keep you safe, whether the alarm uses photoelectric sensors, ionization sensors, or a proprietary method involving a combination of sensors. All the alarms we tested are UL Listed, apart from the First Alert brands, which are tested to UL standards by ETL (which is also a Nationally Recognized Testing Laboratory).
Smoke alarms available today use either ionization or photoelectric sensing. In the fire-safety industry, there is an ongoing debate as to the best use of such sensors to protect people’s homes. Ionization sensors respond slightly quicker to fast-burning fires, while photoelectric sensors are faster at detecting smoldering fires (the more common type in homes). In a properly tested alarm, either sensor should respond to each type of fire within the recommended time.
Ionization alarms, however, are prone to nuisance alarms, making them more likely to be disabled by the home’s residents and leaving that house at greater risk. Ionization alarms have even been banned in some places because of this problem, and they are not recommended for use in kitchens or near bathrooms due to a higher likelihood of false alarms in these areas. Consequently, some authorities advocate for the installation of both types of alarms, others for dual-sensor units that detect both kinds of fires, and others for photoelectric alarms only. The policies vary from state to state. No one recommends ionization alarms only. “While the National Fire Protection Association suggests having both ionization and photoelectric alarms in your home is the optimum situation, our present requirements cover both and will give you adequate warning to get out,” John P. Drengenberg, consumer safety director of UL, told us. “The standard is based on tests that we do to smoke alarms—irrespective of ionization or photoelectric, they both have to pass all of those tests.”
In the end, we wound up testing seven smart fire alarms and similar devices that included options that met our requirements.
How we tested
To test these devices, we put them in a two-story, detached home. We installed both battery-operated and hardwired versions (where available) and used their self-testing features to evaluate the effectiveness of their smart alerts and wireless interconnectivity capabilities. Additionally, we simulated smoke with each device to determine how well the alert features worked in a “real-life” scenario.
We evaluated each device’s companion app, looking at how well and how quickly it sent the notification of danger (if your smoke alarm is doing its job, you really won’t need to spend much time in the app beyond setup). We also connected the devices to any smart-home systems they were compatible with and evaluated the effectiveness and usefulness of any added features.
All the devices we tested responded appropriately to the presence of smoke, and none gave any false alerts during the month they were installed in our test house. Because our test home is not a certified laboratory, we focused our reviews on the ease of installation and use, as well as on the “smarts” each device offered.
The second-generation Nest Protect smoke and carbon monoxide alarm is the best smart smoke alarm for everyone because it reliably and calmly alerts you to potential danger whether you’re home or away, before the actually loud and grating alarm kicks in. It also informs you of problems such as a device malfunction or low batteries without waking you up at a.m. It lets you silence nuisance alarms through its app—so you’re less likely to disable it in a fit of annoyance. On top of that, it interconnects with other Protects to sound the alarm throughout your home, and it integrates with your smart-home system to further mitigate the dangers of a fire or carbon monoxide event.
The Protect’s sensors can detect carbon monoxide, heat, humidity, room occupancy, and ambient light. It also has the Split-Spectrum Sensor, a sensor unique to Nest that, while photoelectric, promises to detect fast-burning fires more quickly than traditional photoelectric sensors do. It accomplishes this with a second LED that may be able to pick up the finer particles of fast-burning fires. This means that while it offers performance similar to that of an ionization alarm, it is less likely to suffer from nuisance alarms.
Perhaps most important, the Protect self-tests its functions every 200 seconds, in addition to performing a sound check once a month to test its speaker and horn. Colored status lights (green for good, yellow for problems) let you know the Protect is working properly. While a couple of the other smart alarms we tested conduct self-checks, none of them do so in a way that’s so visible to the user. For example, the First Alert Onelink battery-powered alarm is completely dark at all times unless there’s an emergency, a design that often led us to wonder whether it was working at all. In contrast, if your Nest Protect is glowing yellow, it will announce what’s wrong, or you can look at the app to see what the issue is. That type of peace of mind is worth a lot in our opinion.
When the Protect is triggered, the alert takes you to the app, where you can silence the alarm. If smoke or CO levels are too high, it will tell you that it can’t silence the alarm and will give you guidance on what to do next.
The Protect’s home-automation capabilities are what make this model truly smart, and the winner among smart smoke alarms. Chief among those features is compatibility with the Nest Cam, which will start recording video if an alarm sounds (you need a Nest Aware subscription), and the Nest Learning Thermostat, which will shut down the HVAC system to mitigate the spread of the fire. An HVAC unit can be the cause of smoke or fire events in a home, and shutting it off is often one of the first things a fire crew does when arriving at your house. Additionally, if you have a Nest thermostat, your Protect alarms can act as motion or occupancy detectors to feed data to your thermostat about whether you are home or not.
The Protect integrates with other connected devices through the Works with Nest program. In our testing we linked it to Philips Hue colored light bulbs, and they flashed red when the alarm activated. Among other integrations, the SkyBell HD video doorbell will turn red if the Protect senses smoke or carbon monoxide inside, the Rachio smart sprinkler controller will cycle your sprinklers if the Protect senses an emergency, and Lutron smart shades will open in the event a fire is detected so that emergency responders can see inside the home.
Nest also offers an extensive IFTTT channel, so you can set up additional alerts and other smart-home customizations. But a lot of the functionality that the IFTTT recipes offer is already available in the native app or through the app of a Works with Nest partner. Due to the lag time you may experience while using a third-party, cloud-based option like IFTTT—which also won’t work if the Wi-Fi is down in your home—we recommend enabling features via the native app or a Works with Nest partner app first and using IFTTT only if you can’t find a suitable option for what you want to do.
Flaws but not dealbreakers
When the Protect debuted in 2013, it saw a slew of owner complaints about false alarms that couldn’t be silenced (UL standards require that certain types of alarms prevent silencing to discourage people from ignoring a dangerous situation). These were false alarms—that is, instances when the alarm went off for no obvious reason—as opposed to nuisance alarms, the kind that sound when burnt toast sets them off. Nest recalled the first-generation Protect in 2014, primarily due to an issue with a wave-to-silence feature that the company has since disabled. After the launch of this redesigned second-gen model, complaints about false alarms subsided but did not completely disappear.
Nest told us that its research into such complaints revealed that the majority of people encountering this issue were using first-generation Protect models. Second-generation models that produce false alarms are most likely affected by a buildup of dust, the company’s representative said, which can clog the sensors. If you experience this problem, Nest’s recommendation is to wipe the device regularly with a clean, dry cloth.
Nest offers only a two-year limited warranty for the Protect, in contrast to seven to years for all the other smart alarms we tested.
The battery-powered Protect uses six AA lithium batteries, and how long those will last depends on how much use the device gets. Some owners have complained about their alarms chewing through batteries in a matter of weeks. Nest’s response is that “75% of low battery reports we’ve investigated occurred when people replaced them with standard AA batteries, rather than purchasing the lithium ones recommended.” The battery-powered Protect uses its batteries regularly for the Pathlight feature, and if your device is in a little-used room, the batteries will probably last the suggested five years. But if you have it in a hallway, the frequent activation will drain the batteries more quickly. Nest recommends disabling Pathlight or setting it to the lowest brightness level if battery drain is a problem.
Who else likes our pick
Roost’s smart functions come as a battery that you install in any smoke alarm, or as a complete alarm with the battery already installed. Photo: Jennifer Pattison Tuohy
If notifications when you are away from home are your main priority, a Roost Smart Battery is an excellent, inexpensive choice. This 9-volt smart battery is not a smoke alarm itself, but thanks to its built-in microphone and Wi-Fi chip, it can turn any smoke alarm powered by a 9-volt battery or hardwired with a 9-volt backup into a smart one. Roost’s smart functions are also available in two hardwired alarm models, one for smoke only and another for smoke and CO, both with the Roost battery included.
Once connected with the Roost app, the battery will send you alerts when the alarm goes off. Since you tell the battery upon installation where it’s located, it can tell you where the danger is, and it will send you an alert when the alarm stops, so you know whether the danger has passed (the Nest Protect also does this). You can silence any battery-only alarm from your phone (though you can’t do the same with hardwired alarms), and you have no need to worry about a.m. battery chirps—you’ll get a notification long before the battery runs out.
Once you sync the Roost battery with the app and install it in an alarm, you’ll receive alerts when an alarm goes off, as well as another alert when it stops. The Nest Protect and the Roost are the only two alarms we tested that also follow up to let you know if the danger has passed.
The Roost battery doesn’t offer any other smart features, apart from some basic IFTTT recipes, and it doesn’t integrate with other connected devices in your home, but we think Roost’s lack of extensive smart-home features is actually a plus for people who are confused or concerned about having too many IoT devices in their homes. This simplicity makes Roost a good choice for any homeowner who isn’t interested in the home-automation aspect of smart-home technology and doesn’t want to pay for such features.
The Roost 9-volt battery has a Wi-Fi radio built in. Photo: Jennifer Pattison Tuohy
In October 2016, Roost introduced its own line of smoke alarms, developed in partnership with Universal Security Instruments, the number three fire-safety manufacturer in the US. The Roost alarms are actually just standard alarms, but each comes with a Roost battery to add the smarts. This addition to Roost’s offerings gives you two more budget-friendly options for outfitting your home with smart smoke alarms. So, on top of retrofitting old alarms, you can buy a Roost Smart Smoke Alarm that can detect CO, all types of smoke (Roost uses a modified ionization sensor, called IoPhic, made by Universal Security Instruments), and natural gas, or you can get a cheaper smoke-only alarm. Note, however, that we don’t recommend IoPhic-based alarms due to their poor customer reviews.
The new Roost alarms are hardwired only, but with Roost batteries in them for backup (all hardwired smoke alarms have battery backups so that they will continue to work if the power goes out). The downside, as mentioned above, is that you can install hardwired alarms only where your house has wiring to support them. But if you already have a hardwired, interconnected system in your house, just one Roost battery in one wired smoke alarm will work to alert you when any of the interconnected alarms go off, making that the least expensive complete-home-retrofit option. (Battery-powered Roost-branded alarms that you can install anywhere in your home are coming soon, according to the company.)
The Roost-branded alarms are slightly more stylish than the standard Kidde and First Alert devices you might be used to, although not as attractive as the Nest Protect. They are designed to last approximately seven years (the Protect promises to last 10), while the included battery should last five years.
During our testing, the option to silence certain types of alarms through the app did not work well. For example, when we were cooking in the kitchen and the smoke activated the alarm, a full 4seconds passed before the alert came up on our phone to let us silence it. By that point we had already grabbed a kitchen stool and pressed the silence button on the alarm itself.
The First Alert Onelink looks similar to the Nest Protect and has many of the same features, but in our tests it was slower to send out alerts than any other alarm. Photo: Jennifer Pattison Tuohy
Seemingly cut from the same cloth as Nest’s Protect, the First Alert Onelink has the same ring of LED lamps to alert you to danger (red) or malfunctions (yellow), offers both voice and location alerts, and lets you silence alarms through its dedicated app. However, many of the Onelink’s features are just pale imitations of the Protect’s offerings, and we were particularly unimpressed with the full two minutes it took to push alerts to our phone and allow us to silence the alarm. The Protect took well under 30 seconds.
Like the Protect, the Onelink has a wireless interconnectivity feature. Unlike the Protect, however, it also offers the option of a wired interconnect system and will work with some existing wired systems, so depending on what you have installed you may be able to buy a single Onelink and give all your existing hardwired alarms some smarts. This feature could be crucial if your home is already equipped with wired First Alert detectors. We weren’t able to test this feature, but CNET notes in its review that while the alerts from a single Onelink alarm transmitted to the “dumb” ones dependably, signals going the other way were very slow, with alerts sometimes taking up to two minutes.
The Onelink is the only Apple HomeKit–certified smart smoke alarm available now, but due to a firmware issue it doesn’t currently work with HomeKit under iOS The alarm is still fully functional, it just doesn’t support control via HomeKit, so we couldn’t test those features. (See What to look forward to for more on this topic).
The other two currently available smart smoke alarms, the First Alert Z-Wave Smoke/CO Alarm and the Kidde Wireless Interconnected Combination Smoke and Carbon Monoxide Alarm, are “smart” only when you use them with a smart-home hub such as Wink or SmartThings. If you already have one of those two systems in your home (or plan to put together a system using one of them), these alarms could be a good option.
The First Alert Z-Wave Smoke/CO Alarm (ZCOMBO) was our favorite of the two alarms that work with a smart-home hub. We tested it with SmartThings, but it’s compatible with other Z-Wave systems apart from Wink. The SmartThings app interface is a lot more intuitive than the Wink/Kidde version, offering a useful alert screen when the alarm goes off, where you can interact with all your connected smart devices activated by the alarm (as opposed to just getting a notification from Wink). You can also silence the alarm from there, which you can’t do with Wink.
On the positive side, if you have compatible cameras, lights, locks, and a sound system, you can set up automatic routines to record footage, turn your lights red, unlock your doors (so that the fire department doesn’t break them down), and have your compatible sound system say “Fire alarm” if triggered. Without any of those devices in your home, however, you will merely receive a push notification that an alarm has gone off.
Because it’s often offered at a discount in multi-packs, the Kidde Wireless Interconnected Combination Smoke and Carbon Monoxide Alarm is the least expensive smart smoke alarm, albeit with the least flexibility and features. It is nicer looking than the First Alert Z-Wave model, with smooth corners and an elegant rounded shape, but it doesn’t come in a wired version, it has only an ionization sensor, and it operates on three standard AA batteries, meaning low-battery chirps are still a possibility. It also works as a smart alarm only if you connect it to the Wink smart-home hub.
Once you connect it to Wink, you can set up Robots to trigger other smart-home devices to act if an alarm is activated, but the Wink app integration is limited—you can set up low-battery alerts and receive notifications if your alarms are activated, but that’s pretty much it. You can’t silence the alarm from the app, and many customer reviews complain that Wink didn’t always trigger their Robots when an alarm went off, rendering the smart-home integration useless.
What to look forward to
In its guide to smoke and CO alarms, Consumer Reports issues a challenge to all smoke alarm manufacturers to create “a single device that senses both kinds of fire and CO.” The Nest Protect’s Split-Spectrum Sensor purports to cut down nuisance alarms by including a type of ionization sensor, but it isn’t a dual detector. However, two smart smoke alarms coming soon promise to offer true dual-sensing smoke detection, with both photoelectric and ionization sensors.
Halo Smart Labs’s Halo incorporates sensors that detect all types of fires, as well as CO. It also offers voice alerts and a glowing red ring to indicate danger, plus a 10-year battery. A second unit, the Halo +, incorporates weather and disaster alerts, covering tornadoes, floods, and hurricanes. Halo Smart Labs told us that the devices will be shipping in December.
Birdi distinguishes itself by offering air-quality and weather monitoring in addition to providing dual smoke sensing and CO detection. According to its website, Birdi tracks dust, VOCs, temperature, and humidity, as well as how stale the air is inside your home. Outside, it tracks pollution, pollen, and particulates, and provides weather tips. According to the Birdi blog, it will be shipping in late November, and it is an Apple HomeKit partner.
Speaking of HomeKit, as we mention above, First Alert’s Onelink is technically HomeKit compatible, meaning you should be able to set up automations to trigger when your alarm detects smoke or CO. However, due to a firmware issue this functionality isn’t currently available with iOS and the Home app. A fix is coming soon, according to the makers of the Onelink, and once it arrives we’ll update our review. In the meantime, you can still use Siri to ask questions such as “Is there smoke upstairs?” or “How is the carbon monoxide alarm?” But we imagine the usefulness of this function is pretty limited.
Kimberly Alt, Smoke Detector Reviews: BRK vs Kidde vs First Alert vs Nest, A Secure Life, August 5, 2016
Dann Albright, Smart Detectors That Protect Your Family and Property From Harm, MakeUseOf, June 5, 2015
Roberto Baldwin, Nest Protect review (2015), Engadget, September 16, 2015
UL 217: Standard for Smoke Alarms
Know the Basics of Smoke Detector and Fire Alarms
Some fires flare, while others smolder. Be sure to choose a smoke detector that can sense both types of fires. Here are the most common types of smoke alarms. • Ionization Alarms – These are excellent at detecting small particles characterized by fast, flaming fires. They are best installed in stairwells and upstairs landings to reduce the incidences of false alarm from steam and burnt food. • Photoelectric Alarms – These are ideal for detecting large particles in smoky, smoldering fires. You can install these in places such as kitchen or bathroom. • Dual-sensor Alarms – These combine both the ionization and photoelectric technology. They are the best choice if you don’t want to go through the trouble of buying multiple detectors.
Hardwired vs. Battery vs. Plug-in Alarms
Most hardwired smoke detectors and fire alarms are designed to tie in seamlessly with your home’s wiring but will need professional installation. Most run on household current and come with a battery backup for fire detection when there’s no electricity.
Battery powered alarms, on the other hand, are easy to install and don’t required electrical power to function. Nonetheless, they need a battery replacement now and then. Units running on lithium battery may last for up to years without a replacement.
You may choose to buy a plug-in alarm, but you also need to be wary of the fact that electric outlets are located low on the wall, while the best place to install an alarm is on or close to the ceiling.
The sound of a fire alarm can create a nuisance, so you need a unit that comes with a hush button to silence it. The button allows you to stop the alarm without necessarily disabling it, which eliminates the likelihood of forgetting to switch it on.
Special Alarms That You May Consider Buying Depending on Your Needs
Some smoke detectors and fire alarms are specially designed to cater for particular needs. They include: • Strobe Light Alarms – These come with a built-in strobe light and can provide the best warning for individuals with a hearing problem. • Voice Alarms – These use a voice command and can be ideal for waking up children who may not respond to a beeping sound. Even though it is not proven that is the best way to wake children, research shows that children who sleep past their alarms wake up to the sound of their mother’s pre-recorded voice. • Safety Lights – These are designed to give an illumination path which could come in handy in the dark.
Important Installation Tips • Outdoors or in direct sunlight • Humid areas • Within twenty feet of appliances such as water heaters or sources of heat such as furnaces • Close to ceiling fans, open windows, air conditioners and heat vents
Ionization Smoke Alarms
An ionization smoke alarm works by sending a small amount of radioactive material that conducts electricity through the air between two electrodes. When the current of electricity is triggered by smoke particles released by a fire, the alarm sounds.
Ionization smoke alarms respond more quickly to fast flaming fires e.g. a fire started with a flammable liquid, like gasoline.
Another benefit to ionization smoke alarms is that as the battery fails, so does the electrical current which causes the alarm to sound (usually a chirping sound) – this feature can help you stay on top of maintenance.
Photoelectric Smoke Alarms
A photoelectric smoke alarm uses a beam of light and a light sensor. As smoke comes into contact with the light beam, the beam will redirect towards the light sensor, and when it reaches a set level, will sound the alarm.
Photoelectric smoke alarms respond more quickly to smoky fires. Most household fires start as smoky fires, such as a smoldering couch that catches fire from a cigarette or lighter.
A negative to photoelectric smoke alarms is that dust or household insects that come into contact with the light beam can set off the alarm. Make sure the smoke alarm comes with an insect screen.
In order to ensure that all fires are detected efficiently, both types of alarms should be installed in your home or a dual ionization/photoelectric alarm should be considered.
While most smoke alarms are either ionization or photoelectric there are now combination units that include both types of sensors. You can also find combination units that include a smoke alarm and a carbon monoxide detector. Typically these combination units use ionization sensors, which as discussed are not as good for detecting smoky fires, so if you install one of these combination units, you probably want to install a photoelectric smoke alarm as well.
SMOKE DETECTOR FEATURES
It’s important to understand that no matter what type of smoke alarm you install, they have a life of roughly years. Many consumers don’t realize that a smoke alarm is continually working. It does not just work at the first sign of smoke; it is consistently monitoring the air throughout your home. It doesn’t matter if its battery operated or hard-wired, the smoke alarms still have the same shelf life. Unfortunately, these simple and potentially life saving alarms are often not maintained properly. The features listed below will help you maintain your smoke alarms and maximize their benefits.
Many alarms are battery operated, but as today’s home construction becomes more advanced, alarms are being hard-wired into the home. Most alarms that are hard-wired are also equipped with a battery backup in case the electricity goes out. Batteries are either 9V or the 10-year lithium.
A smoke alarm should be put on routine maintenance checks, just like other large household appliances like furnaces and water heaters. Smoke alarms should be tested once a month. Read the manufacturer’s directions for testing instructions.
How smoke alarms work
Optical smoke alarms: Also known as photo-electric smoke alarms, this type applies the light scatter principle. They comprise of a pulsed infra-red LED that checks for smoke particles by pulsing a ray of light into the sensor chamber after every seconds. In the absence of smoke, this beam keeps passing in front of the sensor. Once a fire breaks out, smoke enters the optical chamber through vents. As the smoke crosses over the ray of light, its particles scatter some of the infra-red light onto the photodiode light receptor, which triggers the alarm by sending a signal to the integrated circuit.
Ionization smoke alarms: This type ionizes the air between two oppositely charged electrodes as the alpha particles pass through the chamber, creating a small constant electric current. When there is a fire, the smoke particles that enter the chamber absorb the alpha particles, charging the balance of current. This change in current will only occur if enough smoke enters the chamber. The uninterrupted electric current sends a signal to the integrated circuit, causing the alarm to sound.
High-quality smoke alarms feature insect screens to keep bugs from entering the chamber, reducing the likelihood of false alarms.
Photoelectric smoke alarms
This type is a nephelometer or scattered light sensor that consists of a light source, a lens for focusing light into a projected beam, and a sensor angled to the beam. Thanks to the optical technology, photoelectric smoke alarms are not as prone to false alarms as their counterpart.
Combination smoke alarms
This type includes the features of both the ionization and photoelectric alarm systems. While the photoelectric technology responds to smoldering, low-energy fires, the ionization technology responds to rapid, high-energy fires.
Smoke detectors are also classified in two categories, namely:
Hard-wired smoke alarms: This type is wired to your household’s main electrical circuit.
Battery operated smoke alarms: This type is generally powered by a 9V detachable or non-removable battery. Lithium batteries are long-lasting and can last as much as years.
What to look for
When it comes to choosing a smoke alarm, compliance with Australian Standard 378is the most important feature. Make sure the Australian Standard’s logo is clearly displayed on the package. Here are some of the other features to look for:
Tips from the Pro
When choosing a smoke alarm system, there are other factors to consider besides the type of sensor. These variables include:
Location: Smoke can set off ionization alarms, so photoelectric alarms are the best choice for the kitchen. You need to place a smoke alarm near the kitchen because cooking is the leading cause of residential fires.
The size of your property: Most houses need to have a smoke alarm installed in every room, attics and basements included. You may need to place smoke detectors in both ends of the stairways and hallways near bedrooms.
The main part of the legislation, aside from ensuring the correct number and types of detectors are fitted, is to ensure that they are working on the day that the tenancy starts. Once this has been done it can then be the tenant’s responsibility to test at regular intervals during the tenancy and to notify you if any detector is not working. If they are battery operated then it will be the tenant’s responsibility to replace, but if mains-wired it would be the landlord’s responsibility to fix.
Smoke Alarm Accessory
There’s nothing more critical than having a working smoke detector in your home. Its loud, piercing alarm should wake you if there’s smoke or fire, so you and your loved ones can safely escape, or put out the fire.
Another benefit of a smart smoke detector is that you can temporarily silence the alarm from your smartphone — so there’s no more trying to jab the Silence button with a broomstick after you set it off while cooking a steak.
The way to future proof your smart home is to use a hybrid technology solution and to employ technology abstraction. The use of wires and cabling should ensure that you can connect and upgrade sensors when needed. The underlying principle of providing power and getting a signal back is likely to remain valid for a very long time. Wires are also extremely reliable technology and my preferred approach to any home automation.
For this reason we have used standard alarm cable for basic (digital) sensors and Cat5e cable for anything that might require data networking. 1Gpbs data transfer should support all the sensors we can envisage for many years and even then we have installed cables in ducting so that even they can be upgraded later if need be.
If smoke sensors are simple and dumb, they can be easily and cheaply swapped out and the interface to them is unlikely to change much over long periods of time. They can be treated as simple, powered switches. The internal technology can be improved and upgrade over time but the interface remains unchanged and integration of this and any other sensors into our smart home is a simple process, using common infrastructure and components (e.g. USB or Ethernet IO board).
This model applies to pretty much all sensors in the home and is why we use wired magnetic contact sensors on all the doors in our home. Such technology is likely to have a useful lifetime in excess of 50 years.
The Nest Protect is a thing of beauty and very well engineered too but, my ideal smoke alarm would be invisibly integrated into the structure (ceiling or wall) of our smart home (so long as its air flow and sensitivity is not restricted). Smoke alarms are structural elements of the smart home that don’t need to be seen. Just knowing it is there and do its job is enough. I’d rather buy sensors that are white, compact and beautiful, if invisible is not an option. We also consider flashing lights a distraction.
With an off-the-shelf 12V smoke alarm such as we are using now, there are just three simple connections to the alarm sensor itself. These are ground, +12V dc and trigger output. I use standard alarm cable which is cheap and extremely reliable.
Power & Batteries
My approach has been to use a centralised and shared 12V Uninterruptible Power Supply (UPS) for all the essential features in our smart home. This shares the cost of the infrastructure across all smart home functions and provides increased reliability and control.
The Nest Protect comes in two forms
The use of a battery powered Nest Protect is not a step forward in our view and such a device with Wi-Fi and other technology will result in regular battery replacement. I have taken every opportunity to replace battery powered sensors in our home and where this is not possible we have ensured that these devices can report batteries levels back to our Home Control System (HCS), which can then inform us that they need replacing before they run flat. Nest only recommend one type of battery is used in the device, the Energizer Ultimate Lithium batteries (L91).
I have implemented a common alarm system that covers the whole house and can be clearly heard in every room, not just local to the smoke alarm. This is essential in a large house. All of the sensors in our home are effectively linked to it and have the ability to invoke its features.
Our smart home alarm system also has a much wider range of capabilities. This includes an internal alarm, external alarm, external strobe, voice announcements, SMS messaging and IP messaging. This is a common common capability of our Home Control System (HCS) and can be utilised or triggered by any sensor in our home, with the appropriate channels being used based on the sensor triggered and the house status. This also avoids each type or brand of sensors duplicating alarms and notifications.
The smoke alarm modules we use have both audible and visual alarm capabilities on-board but, we can disable these if need be (depending on where the sensor module is located).
Mobile apps can be a really useful way to interact with your smart home but, if I have to install an app for each each brand of device then life is going to get confusing and complicated. A far better approach would to be to have one common mobile app that supports your whole smart home.
Because this is beyond my current coding capabilities I have used SMS/iMessage for notifications and also have a natural language interface and web app for remote access.
If you already own a Nest Thermostat, then the Nest Protects can act as secondary occupancy sensors around your house to tell the thermostat that you are still at home, even if you haven’t passed by a thermostat for a while. This would keep your thermostat from putting itself in Away mode because it thinks you have left the house.
This is no substitute for proper smart home presence and occupancy detection as we have implemented in our smart home. Occupancy detection needs a much greater number of sensors to work well and different types of sensors to work accurately. Such a hybrid technology approach is beyond the scope of the Nest Protect.
Nest state: “We all know why smoke alarms are torn off the ceiling or missing batteries: because every time you make stir-fry, the smoke alarm cries wolf. Or just as you’re falling asleep, you hear a low-battery chirp. They’ve become annoying. And that’s a safety issue.”.
In the 1years we have spent in our current home, the smoke alarm has gone off just or times. In two cases it was due to burnt toast. In the other case, it was something left under the grill by accident and in this instance there was actually a small fire. This isn’t really much of an annoyance in my view.
This video shows the mains sales features of the Nest Protect:
Nest Wave lets you silence nuisance alarms with a wave of your hand and is slightly less of a gimmick but, it will be used very infrequently. It involves waving your arms at the smoke detector, which is kind of what most people do with their current smoke detector.
First of all thanks for reading my article to the end! I hope you find my reviews listed here useful and that it allows you to make a proper comparison of what is best to fit your needs and budget. Don’t be afraid to try more than one product if your first pick doesn’t do the trick.
Most important, have fun and choose your Smoke Alarms wisely! Good luck!
So, TOP3 of Smoke Alarms
- №1 — First Alert 9120B6CP 120-Volt Wire-In With Battery Backup Smoke Alarm
- №2 — Kidde i12040 120V AC Wire-In Smoke Alarm with Battery Backup and Smart Hush
- №3 — First Alert SA303CN3 Battery Powered Smoke Alarm with Silence Button