Best Carbon Monoxide Detector [Top 11 Reviews]
What is the Best Carbon Monoxide Detector?
Carbon monoxide detectors are as important to your home safety as smoke detectors are. Carbon monoxide (CO), frequently called “the silent killer” is one of the most prevalent causes of death due to poisoning in the United States.
The reason behind this is because it doesn’t have any odor, taste, or color and it is practically impossible to detect it by smell or visual cues. Any time you burn something, such as charcoal, gasoline, propane, wood, or natural gas, CO is released into the air. Usually, this isn’t a health hazard in outdoor spaces since there is plenty of space for the gas to dissipate.
However, when CO is released in enclosed spaces such as your apartment or garage, the gas poses a serious hazard.
Carbon monoxide detectors are very similar to smoke detectors. The only difference is that, instead of looking for signs of smoke detection and fire, they detect high levels of carbon monoxide. And, a carbon monoxide detector doesn’t necessarily have to be placed near the ceiling level.
These devices are relatively inexpensive, widely available, and powered by battery or AC. Usually, it is recommended to install the detector around heaters, stoves, and similar appliances. If it detects a high level of carbon monoxide, the device will sound an alarm and warn everyone to ventilate and evacuate the place.
If you are interested in buying a carbon monoxide detector, take a look at some of our favorite picks!
If you’re in a hurry, take a look at these Amazon Best Sellers. Otherwise, keep reading!
As an Amazon Associate I earn from qualifying purchases. Last update on 2022-01-10 from Amazon / Images from Amazon Product Advertising API
The Best Carbon Monoxide Detectors for January 2022
Here are the top 11 Best Carbon Monoxide Detectors for January 2022.
1. Top Pick – First Alert Onelink Safe & Sound Carbon Monoxide Detector and Smoke Alarm
- About safe and sound: First Alert introduces Onelink Safe and Sound, an Alexa enabled, Apple HomeKit compatible hardwired photoelectric smoke and electrochemical carbon monoxide alarm, featuring a...
- Easy mobile controls: Get remote notifications of an emergency in your home for 24/7 safety, plus track carbon monoxide levels, customize nightlights, and more, using First Alert's Onelink Home app
- No more confusing beeps: Track battery levels in the app and optimize safety by knowing when it’s time to replace them. AirPlay 2 enables a wireless multi room audio system, creating an easy way to...
As an Amazon Associate I earn from qualifying purchases. Last update on 2022-01-10 from Amazon / Images from Amazon Product Advertising API
There are so many reasons why Onelink Safe & Sound is our top pick, and the first one is its manufacturer. First Alert has been keeping homes safe with its smoke and CO detectors for more than forty years. And now, they’ve released their most innovative alarm yet.
Onelink is one of the smart carbon monoxide alarms that connect to your home network and sends notifications directly to your smartphone. In addition, the unit works with Alexa and this means that it can do everything an Amazon Echo can – tell you the latest news, give you sports scores, and also lets you control your other smart devices.
This carbon monoxide detector can also transform into a powerful speaker whenever you are in the mood to play some music from your Amazon library or your smartphone. Onelink Safe & Sound is also compatible with Apple’s HomeKit. However, the unit lacks AirPlay, so you won’t be able to use it to stream music.
One great thing about Onelink is that it’s not just a carbon monoxide alarm but it is also a smoke detection and fire alarm. The fact that the unit can do double-duty makes up for the fact that it is a bit larger than your average smoke detector. But, since the unit is ceiling-mounted, you’ll quickly forget that the unit is there.
In addition, this CO detector uses its placement to its advantage to deliver a pretty impressive bass, but it won’t get as obnoxiously loud as, for example, Google Home sometimes gets.
With Onelink Safe & Sound you’ll never have to worry that power outages or lost internet connection will affect its function. Created as a combination unit featuring a photoelectric smoke alarm and electrochemical carbon monoxide detector, the components will work as intended even when the power goes out.
In case a fire occurs, the unit will sound a piercing alarm paired with a pleasant voice that will let you know the source of the fire. In addition, you will receive a notification on your smartphone and, if your home is wired to support interconnected alarms, all of them will be triggered.
As we already mentioned, the Onelink Safe & Sound is one substantial carbon monoxide and smoke detector. But, an important thing is that it features a modern design and that the unit is quite likely to blend into the ceiling.
Square-shaped with rounded corners, the unit features a smaller rounded square in the middle that’s ringed by LEDs which turn blue when Alexa is listening. The LEDs also serve as a nightlight and you can use the Onelink app to change their color and brightness. Of course, you can also have the light turn on and off at set times.
Reliable Mobile App
All smart carbon monoxide alarms come with a mobile app, and so do Onelink Safe & Sound. The app is available for Android and iOS devices and also quite easy to use.
Once you open the app, you will find your Home name at the top of the screen. Right below it is a status bar that displays if everything is OK in your home. You can also use the app to adjust the nightlight, disable the microphone, and put Alexa voice service to sleep.
Smart Carbon Monoxide Detector with Alexa Integration
With the help of the Onelink app, you can connect this CO detector to Alexa, but also Spotify, TuneIn, Pandora, SiriusXM, and iHeartRadio.
But, since we’re talking about a smoke and carbon monoxide alarm, this unit doesn’t have all of Alexa’s features. For example, you can’t group it with other Alexa speakers or use the Drop In feature.
A Bluetooth Speaker
If you’re an audiophile, you probably are not going to want to use this unit as your primary speaker. But, if you’re fine with an average speaker that has a clear sound, then you’re good to go. Onelink Safe & Sound can play music, Alexa’s voice is easy to understand, and the alarm is loud and clear (85-decibel). What more can you ask for?
First Alert Onelink Safe & Sound Pros
- A multi-purpose device that comes with a nightlight and Bluetooth speaker.
- Compatible with Alexa, Google Assistant, and Apple HomeKit.
- Easy to install.
First Alert Onelink Safe & Sound Cons
- The unit is pricey.
- Requires hardwiring.
- Does not support IFTTT.
- Limited Alexa functions – can’t connect to another Alexa or Google Assistant device to play music or communicate.
- The unit can’t play music if another Alexa device is currently playing music.
2. Runner Up – Samsung SmartThings ADT Carbon Monoxide Alarm
Are you looking for a way to turn your home into a smart home? Well, the Samsung SmartThings ADT carbon monoxide alarm is then a must-have for you. What is great about this CO detector is that you get a smart device for an incredibly affordable price.
You can program it to send you alerts or turn other connected devices on and off if carbon monoxide is detected in your home. Also, the unit can help you ensure your home’s safety by sending you reminders about your door locks, for example, or setting lights.
In addition, you can add other SmartThings devices such as cameras, doorbells, thermostats and connect them to your CO detector.
So, if this detector is smart and affordable, why is it in the second place? There is one simple explanation; in order for this unit to work, you need to have SmartThings ADT Security Starter Kit which is sold separately.
The unit will not pair with any other ADT panels or SmartThings Hub. But, the good news is that you can also get ADT professional monitoring services for a low fee as well!
Installing carbon monoxide detectors is not always easy, but with this one, it really is a piece of cake. The manufacturer thought of almost everything. You can choose to install the unit on the ceiling or a wall. And, for those difficult-to-wire locations, you can always go for a wireless option.
ADT’s Customer Monitoring Centers
Usually, a carbon monoxide detector will simply trigger the alarm and send you alerts if high levels of CO are detected. However, this unit will not only alert you but also the ADT’s Customer Monitoring Center. As soon as this happens, you will receive a phone call and, if necessary, the center will notify first responders.
A Smart Device
Similar to other carbon monoxide detectors, the ADT Carbon Monoxide Alarm will send alerts to your smartphone if CO is detected in your home so you can act accordingly.
Thanks to the accompanying app, you can take action even if you’re not at home. For example, you can turn off the air vents to slow the circulation of deadly gases or unlock all doors so first responders could come in.
It doesn’t matter whether you’re at home or out of town, the ADT CO detector will provide protection for your home. You can relax knowing that as soon as the unit detects something out of the ordinary; it will trigger an alarm, alert you, and also contact the customer monitoring center.
- An affordable unit.
- Sends alerts directly to your smartphone or email.
- Connected to the customer monitoring centers.
- Supports automation with Samsung SmartThings.
- Professional monitoring is available on an as-needed basis.
- Only works with SmartThings ADT Security Starter Kit.
- Additional hardware and devices might be expensive.
3. Best Smoke Alarm and Carbon Monoxide Combo – Google Nest Protect Smoke and Carbon Monoxide Alarm
- Smoke detector and carbon monoxide detector that speaks up in a friendly voice to give you an early warning when there's smoke or CO in your home
- Split Spectrum Sensor looks for both fast burning and smoldering, and tells you where the danger is
- Get phone alerts so you know something's wrong even when you're away from home
As an Amazon Associate I earn from qualifying purchases. Last update on 2022-01-10 from Amazon / Images from Amazon Product Advertising API
If you’re looking for the best smoke alarm and carbon monoxide detector combination, then look no more. The Nest Protector is a dual-sensor unit that detects smoke much faster than other standard detectors. It is a “split-spectrum” sensor, meaning that it can detect both smoldering and fast-burning fires quickly and accurately.
In addition, the Google Nest Protect is also a smart device. This means that you can control it remotely, personalize to your preferences, and, keep an eye on your home all the time.
The only downside of this detector? Well, it might be a bit pricier than other standard CO detectors. But, considering all the features that come with it, you definitely get a lot of bang for your buck.
Google Nest Protect Integrations
One great thing about this Nest carbon monoxide detector is that you can connect it to your other Nest products. With the Nest app, you can monitor all your devices including the smart thermostat and indoor/outdoor security cameras.
In addition, you can also incorporate this product into your home automation system. The detector can connect to many other smart devices including Amazon Alexa, Whirlpool smart washer and dryer, Philips Hue bulbs, and WeMo Switch.
Nest Protect smoke and CO alarm proved to be very reliable. It won’t go off when you burn your toast, but when it detects the danger it will sound a very loud alarm. Once the smoke or CO starts to fade, the Nest detector will let you know through the speaker that the smoke is clearing.
What impresses many users is how fast you can silence the alarm. All you need to do is use the app or press a button on the front of the detector.
The Nest App
You can use the accompanying Nest app to monitor the status of your detector and any other Nest products you have. The app gives you detailed information about the devices, such as when the last check was and whether there are any issues.
- The device can detect smoke and carbon monoxide.
- Both hard-wired and battery-operated options are available.
- The device frequently checks itself.
- Integration with other smart devices is possible.
- The unit is expensive.
- Sometimes the detector has trouble connecting to Wi-Fi.
4. Best Portable Carbon Monoxide Detector– Sensorcon Carbon Monoxide Tester & Meter
- This monitor ONLY Detects (CO) Carbon Monoxide. Nothing else. Designed for industrial and commercial applications. Watch the short video for more information
- Even with a presumed presence of CO, (Carbon Monoxide), a measurement of 0 ppm is not uncommon
- Sounds low level alert at 35 ppm and high level alert at 200 ppm
The danger of carbon monoxide doesn’t exist only in your home, but wherever you go. Sometimes, the equipment in hotels and motels is not properly maintained. And, some hotels might not even CO detectors because they are not required safety devices.
So, if you want to sleep soundly, then you should consider getting a portable carbon monoxide detector. This one made by Sesorcon is durable and reliable enough to be used by first responders but also easily used and affordable for all concerned homeowners.
Sturdy and Durable
Sensorcon CO Inspector is an excellent choice for those who don’t care much about the design but only about the performance. The device is very sturdy and also waterproof, made to withstand wear and tear. In addition, it has a sturdy locking clip which can be removed if necessary.
Very Accurate Unit
This carbon monoxide detector is one of the few units available on the market that can detect CO gas concentrations from 0 to 2000ppm. Yes, you’ve read that right. The majority of other detectors can measure levels as low as 30ppm but this one performs even better than that.
The majority of CO detectors need to have their sensors replaced on a yearly basis. However, Sensorcon has developed a CO monitor which can last longer than that.
Unfortunately, the sensor still has to be replaced but it should last you for at least two years. Just keep in mind that the unit should be calibrated yearly, and the manufacturer offers free recalibration.
- Reliable and accurate (up to 200ppm).
- Very durable.
- Highly portable.
- Free recalibration offered by the manufacturer.
- The detector is pricey.
- Cannot be mounted to a wall.
5. Best Plug-in Carbon Monoxide Detector – First Alert Dual-Power
- Keep your family safe with this digital display, plug in carbon monoxide alarm; It works with any standard outlet and also has a battery backup for continuous monitoring of Carbon Monoxide levels,...
- Features an advanced electrochemical carbon monoxide sensor; Peak level feature displays the highest concentration of carbon monoxide measured
- A loud 85 decibel alarm sounds when Carbon Monoxide levels reach dangerous levels
What makes the First Alert dual-power CO detector different from other detectors? First, it comes with a ton of great features at a low price. Then, it has a neat plug-in option which makes the unit incredibly versatile. You can place it in any room as long as there is an outlet.
Last but not least, the detector has a digital display which makes it easy to read the level of carbon monoxide inside your home.
A Plug-in CO Detector
What many users love about this First Alert detector is that you can measure CO levels in your entire home. Since the detector comes with a cable that is six feet long, you can place it in any room and monitor CO levels. In addition, the device has a battery backup.
This means that you can get your CO readings even in the event of a power outage or if there is no power outlet nearby.
This carbon monoxide detector has a digital display that allows you to easily see whether the levels of CO are within the acceptable range. And, unlike many other CO detectors, this one shows clearly whether the levels are low, high, or even dangerous.
The most important feature of any CO detector is its accuracy. First Alert dual-power CO detector uses electrochemical sensors which actually make the unit extremely accurate.
- The detector is affordable.
- It is versatile and can be placed in every room.
- The unit features advanced electrochemical sensors.
- It comes with a digital display that makes it easy to see the exact CO levels.
- The detector doesn’t display readings below 30ppm.
- It might be difficult to close the battery compartment.
6. Best Cheap Carbon Monoxide Detector – First Alert CO400
- Keep your family safe with this easy to use, battery operated carbon monoxide alarm; Battery powered alarms provide continuous monitoring of CO levels, even if there's a power failure
- Features an advanced electrochemical carbon monoxide sensor that accurately detects carbon monoxide levels, no matter where the detector is placed in the room.The alarm sequence should last 5-6...
- A loud 85 decibel alarm sounds when CO levels reach dangerous levels
If you are searching for an inexpensive and easy carbon monoxide alarm, First Alert CO400 is the best choice for you. It utilizes an electrochemical carbon monoxide sensor, which is the most accurate technology nowadays. Its permanent sensor can last up to 5 years. This is powered by a 9V replaceable battery, providing you peace of mind even if there’s a power outage.
The silence or test button both silences the alarm and enables you to test its functionality. The unit re-alarms and monitors if the levels of carbon monoxide persist sounding loud 85db horn. There is no need for installation. Unlike others, it has a stylish design, which enables the unit to be placed anywhere.
This includes an optional wall mount without an outlet needed. Visual and audible low battery signal alerts when you need to replace the battery.
If you still don’t know how to operate this when an alarm sounds, you only have to pull down the action chart. There is also an included five-year limited warranty.
Just mount this on the wall with Velcro tape or a small nail. An alarm will chirp once the batteries are low, sound if carbon monoxide is detected, and it beeps when you press the button for the test.
- It is easy to install.
- No wires to deal with during setup.
- Cheap but high-quality CO alarm.
- Easy to operate.
- No complicated instructions.
- Simple carbon monoxide alarm, but useful.
- No modern technology included.
- Batteries run off easily.
- It is not digital.
7. Kidde Battery-Operated Carbon Monoxide Alarm
- Fire & CO detector in 1 unit with alert modes, LED lights, & voice alarm, that states, "Fire! Fire!", "Warning! Carbon Monoxide!", or "Low Battery!"
- Ionization sensor technology - smoke detector detects invisible fire particles, 85 decibel alarm alerts of fire
- Protects during a power failure - combo smoke and CO alarm operates on 2-AA batteries
The carbon monoxide detector Kidde helps to provide your home with extensive protection against the harmful threat posed by colorless and odorless gas.
With the increasing local and state governments passing legislation needing carbon monoxide alarms in homes, it is never been a good time to safeguard your family against exposure from carbon monoxide.
This carbon monoxide detector measures the carbon monoxide exposure over time. It’s made to sound at 85db at 10ft once this detects 70PPM of carbon monoxide for 60-240 minutes, 400PPM for 4-15 minutes, and 150PPM for 10-50 minutes.
The visible digital display indicates the carbon monoxide level that the unit senses and this updates the status every fifteen seconds for accurate and timely readings. Its free-standing design enables attachment to walls or placement on counters for comprehensive and convenient protection.
This battery-powered carbon monoxide detector also includes a slide-out battery door, which gives immediate access to the power source and battery safeguard that makes it hard to close the cover without the batteries installed.
A LED lighting system in the unit also signals power sourcing and levels. This device has a 7-year expected lifespan and equipped with 5yr limited warranty from the manufacturer.
- Clear and easy to read digital display
- Updates every fifteen seconds
- Installation is made easy
- Available at an affordable price
- One of the highly recommended carbon monoxide detectors.
- There’s no home automation capability.
- You can’t keep track of the details from your phone.
8. Carbon Monoxide Detector Kidde KN-COPP-3 Nighthawk Carbon Monoxide Alarm
- Protects during a power failure - carbon monoxide alarm contains a 9V battery backup in case of plug-in failure
- Easy installation - plug can be installed in any outlet of your home; or use the attached extension cord to place on a table or shelf
- Peace of mind - when CO detection is normal, a red dot appears in the lower right corner & blinks; includes a test button
Kidde Carbon Monoxide Detector continues the legacy of the company known for its creation of fire safety products for more than 90 years. Being the largest manufacturer of fire safety products in the world, Kidde also comes up with top-of-the-line carbon monoxide detectors.
Kidde KN-COPP-3 has a digital display to let you read the carbon monoxide levels in your home easily. This device can also refresh its data after every 15 seconds for you to detect right away if something is amiss. When your device sounds, you will definitely heart it. The carbon monoxide alarm also let out a beep of 85 dB which is as loud as your blender.
What makes this carbon monoxide detector different from others is that it’s equipped with features that are guaranteed to help you protect your loved ones from the danger of carbon monoxide poisoning. It works well and anyone can quickly install it.
Other than that, the best part of this is that it comes with battery backup, which only means that you can enjoy savings. In case your current battery loses its power, you can always use the included battery backup anytime you need this detector to work.
- Equipped with a digital display.
- Most famous carbon monoxide
- Backup battery included
- Less false alarms
- Does its job flawlessly
- Long battery life
- Packed with useful features
- Easy installation
- Only a single sensor.
- The smoke alarm is sold separately.
- No home automation.
9. Sunnec Carbon Monoxide Detector
The Sunnec carbon monoxide detector is very affordable yet also reliable. It features an electrochemical CO sensor that accurately measures CO levels in your home. The detector also features a digital display that shows the level of CO measured in your home.
The alarm is very loud (85 decibels) and it can wake up even heavy sleepers. The unit requires three AAA batteries to operate. In addition, the detector is covered by a 24-month warranty.
10. Forensics Carbon Monoxide Detector
- 🚗 USES: Exhaust leaks in vehicles (i.e. SUVs, aircraft, school buses, trucks & fleet vehicles that triggers headaches, nausea & driver fatigue.
- 🔬ACCURATE: CO low-level alarm at 9ppm & 25ppm alarms WHO, EPA, ASHRAE, OSHA, NIOSH CO recommended exposure levels.
- 🔔 FAST ALARMS: Alarms at >9ppm @ 60 secs, compared to home CO detectors that only alarm >70ppm @ 60-240 minutes. Bright RED LED and buzzer alarms.
Your home is not the only place where you are exposed to CO. FORENSICS developed a small carbon monoxide detector that can be used in cars, airplanes, and all other vehicles.
It is very useful and can be used to prevent headaches, nausea, and driver fatigue. The detector runs batteries and they can last for an entire year. In addition, the unit comes with a one-year limited warranty.
11. Kidde KN-COB-B-LPM Carbon Monoxide Alarm
- CO detector with alert modes & LED lights that pulse for power, CO detection, & low battery
- Sophisticated electronic components to protect you & your family from the dangers of carbon monoxide, 85 decibel alarm alerts of fire
- Protects during a power failure - operates on 2-AA batteries, included with pack
The Kidde KN-COB-B-LPM carbon monoxide alarm is intended for continuous monitoring of CO. The detector requires two AA batteries, which are included, to run. If high levels of CO are detected, the unit will sound a piezoelectric horn that is rated at 85 dB at 10 ft.
Which Carbon Monoxide Detector Works For You?
Things to Consider When Buying a Carbon Monoxide Detector
Statistics reveal that CO or carbon monoxide poisoning claims the lives of more than 400 people in the US alone every year. This dangerous gas is also the culprit which sends tens of thousands more to emergency rooms.
But, there is really no reason for anyone to become a victim of this silent killer, especially now that these tragedies can be easily prevented by installing CO detectors in homes and commercial spaces alike.
However, just like with any other product you buy, there are several very important things you have to consider before you shop for this kind of device to ensure that you will be getting the best possible protection you need. As with anything else, carbon monoxide detectors have not been created equally.
Although it is a good thing that you can now find an extensive variety of these detectors on the market for you to choose from, the wide selection can also sometimes lead to confusion.
You might end up feeling clueless as to what is really the best option that can give you and your family the ultimate protection needed from the deadly carbon monoxide gas.
Here’s what to look for when you shop for these carbon monoxide detectors.
Type of sensor
There are several important factors you should keep in mind when buying a CO detector. Depending on the model, these detectors can operate in one of three ways: using a biomimetic sensor, metal oxide semiconductor, or electrochemical sensor.
Biomimetic detectors use certain gels that change color after absorbing CO and this triggers the sensor to sound an alarm. Metal oxide semiconductors use silica chips for detecting CO and then send electric signals that trigger the alarm. Electrochemical sensors are believed to be the most advanced and reliable option.
They use electrodes in chemical solutions which can sense changes in electrical currents when carbon monoxide is present. Once this happens, the detector sounds the alarm.
When it comes to carbon monoxide detectors, there are several power source options. You can choose from battery-operated or hardwired units, plug-in models, and those that are a combination of battery/plug-in power supply.
Battery-operated units and plug-in models usually allow for more placement options and you won’t have to worry about power outages. On the other hand, wired units are great because you won’t have to constantly think about changing batteries. In addition, most hardwired units have a battery backup in case of power outages.
But, it is very likely that you will need to call a professional to install this type of CO detector for you.
Another feature you should take into consideration is the sensitivity of carbon monoxide detectors. The concentration of CO is measured in parts per million (ppm). The majority of carbon monoxide detectors measure levels as low as 30-40 ppm and they sound the alarm when the levels reach 70 ppm or greater.
However, there are even more sensitive units that can detect levels as low as 10 ppm.
It is important to keep in mind that sensors found inside CO detectors are a sort of wear-and-tear item. They do not last forever, but, the good news is that they can last about five to ten years. So, try to find a unit that will allow you not to worry about replacing the sensors frequently.
There are CO detectors that are conveniently made portable and this is often a favorite among home inspectors and professional installers. Others may also be hardware to the existing wiring in your home. There are some which are powered by batteries and others can be plugged into a wall outlet.
The majority of today’s CO detectors boast of shelf life of 5 to 7 years although some don’t really last this long. There are models which require re-calibration and other forms of servicing every now and then.
As mentioned earlier, these detectors can either be plug-in, battery, or hard-wired models. Each will perform the same function and the specific type you choose is going to depend on your unique situation. But, the most critical feature you have to check, no matter what model you get, is its backup battery.
It is essential because, with no backup battery, your detector will prove to be useless in times of power failures. Unfortunately, it is also exactly during these times when people are most at risk since a lot of them turn their alternative heating methods particularly during blackouts in winter months.
It is best to go for a unit with a digital display. Even if this is not absolutely crucial to the overall function of your detector, it still remains to be highly recommended. You will not only get peace of mind when you see the O there at a mere glance for it will also alert you if there are existing low levels of carbon monoxide but are not enough yet to trigger the alarm.
The alarm is often triggered at 30ppm but even low levels of this gas can already be harmful to some people, such as unborn babies.
When buying a carbon monoxide detector, you can choose between a stand-alone unit or a combination model that can also function as a smoke detector.
When it comes to the combination units, they usually don’t come with digital readouts since they have to be mounted on the ceiling. However, these can help you save some money since you get two devices for the price of one.
Last but not least, you should go for a unit that meets your budget. You can find models with decent features, battery life, and sensitivity that cost about $30. But, there are also some smart models that can be a bit pricier.
Also, don’t forget that you might need more than one unit to protect your home properly, so the costs could add up quickly.
The last equally important thing to consider is who will use the detector. If someone in your home has a hearing impairment, it is best to get a unit equipped with a special light feature to alert a person who cannot hear the alarm.
Of course, the price of such a unit will be a bit higher but you will see the value for your money when you know that everyone is safe and protected.