Should you invest in a smart smoke detector?

Part of the connected home we don't often think about, "smart" smoke detectors provide a mix of extra safety and convenience features, but they come at a higher cost. This leaves a lot of us unsure if a smoke detector like a Nest Protect is worth buying. Let's take a look at what they offer so we can make the decision that's right for us.

See the Nest Protect at Amazon (opens in new tab)

There are a handful of highly rated smart smoke detectors from companies with names we might recognize like Kiddie and First Alert, but most people are familiar with the Nest Protect. All brands tend to offer the same core features and cost about the same, somewhere around $100 for either the wired or battery-powered option. That's quite the jump in price compared to the $15 option available at your local big box store, but you get a smoke detector that's safer — most smart detectors detect fires three different ways — and because they're smart they work with other connected things in your home.

The first thing a smoke detector needs to do well is warn us when there may be a fire. Smart detectors use three different methods here.

The most important feature is alerting you and everyone in your home that there is a fire. A smart detector usually has three different methods that each excel at detecting a certain thing.

Smoke is detected by both a photoelectric sensor and an ionization sensor. A photoelectric sensor is designed to detect when something is smoldering. Plenty of things in your home are fire retardant and will smolder and smoke long before they catch a flame. But if they are next to something that not as fire retardant, a fire can quickly become dangerous. Your furniture, your carpet, much of the clothing you wear and more are things that will smolder long enough to cause an alarm before they can start spreading a fire.

An ionization sensor is designed to detect a flaming fire. They have a small ionization chamber where drawn air can interact with a very small amount of radioactive material (Americium-241). The chamber is designed to transfer a micro-current between two conductive plates, and even the smallest amount of smoke (or any solid airborne particles) will disrupt the current and trip the alarm. You'll find ionization sensors in commercial smoke detectors wherever flammable materials are stored.

According to the CDC, every year 20,000 people visit the hospital and 400 deaths are caused by Carbon Monoxide poisoning.

The third type of sensor is for Carbon Monoxide. CO gas is odorless, tasteless and a by-product of almost every type of fire. Inside your home, it's one of the leading causes of death due to fire because it can reach toxic levels quickly when it is unable to dissipate. Having a CO detector is not only a good idea but mandatory for many insurance policies.

You can find plenty of dual-sensor smoke detectors and stand-alone CO alarms are reasonably cheap. But smart smoke detectors tend to have far fewer false alarms, and if your smoke detectors are hard-wired having all three types in a single unit is a necessity. We want a smoke detector to do only one thing — alert us when there is a fire. When your detector gives you too many false alarms it's not very useful — the original Nest Protect was halted and revamped because of this. Personally, I think this feature alone makes them worth the cost.

Nest Protect

But we can't play down the connectivity. Using the Nest Protect as an example I'm familiar with, I know that the Nest application will alert me on my phone when the alarm is triggered no matter where I am. While I've never had the misfortune of putting things to the ultimate test, I know that even when I'm not home and out of harm's way, I still want to know if there were to be a fire at my house.

Connectivity with other smart devices means visual cues can accompany alarm sounds to warn people with a hearing impairment as well as draw more attention from everyone.

Besides remote monitoring — you can get all sorts of data like Carbon Monoxide levels in ppm, for example — being connected means a smart alarm can talk to other smart devices. You can connect a Nest to a Philips Hue bridge and flash the lights when an alarm is triggered as a visual alert. A connection with a Ring doorbell can add the door chime and a blinking red indicator at the doorbell button so someone who is unable to receive a remote alert would know not to enter. These ideas are extendable. It would be great to see a company that makes smart door locks talk to a smart detector to make sure the doors are unlocked in the case of a fire so a child could get out without trying to unlock a deadbolt or the fire department could quickly enter. Smart homes built around Google Home or the Amazon Echo can easily bridge any number of different smart devices.

Ultimately, spending $100 on something we hope to never use is going to be a decision we each need to make for ourselves. I think it's well worth it, even though I hope I'm being too cautious and never need one.

Jerry Hildenbrand
Senior Editor — Google Ecosystem

Jerry is an amateur woodworker and struggling shade tree mechanic. There's nothing he can't take apart, but many things he can't reassemble. You'll find him writing and speaking his loud opinion on Android Central and occasionally on Twitter.

31 Comments
  • It's simple... put google home into each of these, with decent speakers and we can put them around our house giving us both protection AND a whole house speaker system with google cast support. This is what should have been done the second google bought nest. Then version 2 should include motion sensors in them so we can now have a motion sensing security system. So I guess it's simple to me..... perhaps Google needs to hire me?
  • They actually have motion detectors built in because it is tied into the nest away mode or for path light at night. When it senses you walking by it lights up. I'm a firefighter so I tend to go overboard when it comes to fire safety.
  • I have 7 nest protects. They are awesome. Been running for two years with no issues. Also a gen 1 nest thermostat.
  • Just keep in mind these things expire... Aka they're only good for 3-5 years so it's actually $20-33/year. Granted the smoke detector part will always be good, but the carbon monoxide monitoring won't be.
  • Gen 1 are 7 years.
    Gen 2 are 10 years.
  • Smoke detectors are supposed to be replaced every 10 years. CO detectors every 5. Sorry, but per local code, I have to have 9 smoke alarms in my house. No way am I going to drop a thousand bucks for smoke detectors that do nothing more (they send me tweets...? Big deal) than the detectors I already have. If they go off while we are inside, we'll know. If they go off while we're away, my neighbors will let us know.
  • I say make the modular, the parts that "require replacing" are a piece you pop off and get replaced at their specified interval. The rest is like "dsstrainer" says above, make them an extension of google home. Now you have full house music/intercom/security system that is controllable from your phone. I would LOVE a setup like that. Shooting from the hip:
    Modules can include a wifi repeater, camera, motion sensor, smoke / CO2 sensor, light (Philips can get in on this and now you can have a party all over the house) & temp/humidity sensor for Nest HVAC systems. Each base has 4 ports and goes where your current smoke detectors go (my smoke detectors were replaced in a renovation and have 110v power with the 9v battery as backup. I imagine many are installed that way now) Google really needs to get moving on this.
  • No thanks. I don't need my smoke detectors reliant on an operating system.
  • It's already reliant on NEST OS... and they've already had problems: http://www.sfgate.com/business/article/Nest-smart-smoke-detectors-not-so...
  • Ya me either. The module would be powered via a pass through from the mains (add a 9v battery for backup). Then there would be a connection back to the "hub" for notifications via Nest/home/whatever. It would be able to function as a self contained "dumb" smoke/co2 detector if you were to power it manually.
  • Exactly. I need 7 I am not going to drop $700 when I can drop $105 for a unit with the same exact sensors and is only missing the connectivity part (which is now covered by my home security system and its additional units that will alert me when there is a fire on top of the 7 smoke detectors and 2 CO detectors I already have)
  • I have my Canary (canary.is) setup to alert me if the house gets over 100 degrees. That will let me know if it caught fire while I am not home, lol.
  • I've literally been looking at these this morning and trying to get the upside. I didn't think about the fact that, if I'm not home, I could get an alert about a fire, and using my automation and security packages I have, I could call the fire department with the press of a button if the need arises. Things to think about....
  • Like someone else said, get a good temperature sensor for $40 and you'll be alerted when your house reached above 90 degrees!
  • What I don't understand, is CO detectors are supposed to be mounted low (CO gas is heavier than air) while smoke detectors are recommended to be mounted on the ceiling (smoke rises). Where would a combined device need to be mounted to be effective? or do they detect CO and Smoke differently? I am in the market for Z-Wave/Smartthings-compatible detectors but assume 2 separate detectors would be preferred for reliability.
  • They give specific mounting guidelines to take care of that.
  • I have 2 of the First Alert combo smoke and CO detectors connected to my Smartthings hub. They can alert you when you are home or away through text message/push notification and can also turn on connected lights and unlock my front door when triggered. I still have my "regular" smoke detectors throughout the house too - I figured I would just add to what was already there rather than replace.
  • I have these two, all the features of the best protect for 2/5 of the price..... Save your money folks
  • YES - I got one when the beeping on a standard one kept going randomly even with fresh batteries. Has been a game changer: re-assurance when away from home, auto-tests, night light feature (although I wish the motion detector they use for this could be used in other smart home uses, ie. IFTTT / Wink), battery lasting a while, and looks good.
  • Personally, I just got one from my alarm company. Ties into my alarm system and I can still get notifications on my phone but there's actually someone else monitoring it 24/7. I can see where the Nest would be good if you didn't have an alarm system, but if you do, getting one from your alarm system is most certainly better.
  • I personally went with the First Alert talking smoke/co detectors in each room and a Leeo Smart alert monitor. I saved a lot of money vs Nest and still feel safe knowing I can tell what rooms are triggered by listening, and get notified (and hear the alarms) via phone and app thanks to Leeo.
  • Only if it detects the scent of bud, so I can jump in on the cipher
  • I got one in my kitchen. I like how it lights up in the dark so you can see a little. Other than that... I hope I never have to use it besides when my wife is cooking. Even then it doesn't really go off unless she's getting down with the cast iron. Then it's a pain in the ass to shut off.
  • If they are going to cost that much put a video camera in for security and I'll definately buy it.
  • Unless I'm missing something, the Nest protect does not offer any information on CO levels (ppm) until there is an emergency. That sucks!
  • Smoke and CO detectors need to be in different places. Smoke rises and CO sinks so smoke detectors need to be up high while CO detectors need to be down low. I'm all for having them smart and talk to each other but this is not the right package.
  • Absolutely buy a nest smoke/CO2. It's a no brainer. I own 4 including rental properties.
  • My biggest issue with the Nest Protect is that I need six smoke detectors and even the wired version of the Protect is missing the third relay wire to integrate with the existing "dumb" smoke alarms. If one goes off, they should all go off and I can't do that without $600 worth of Protects. Add the relay wire and I'm in. My kitchen location is perfect for the motion-based night light. Instead, I'll probably just make the dumb ones smart with a SmartThings hack integration.
  • No
  • Agree w/ you here Jerry. I have two Nest Protects in my house so I can be alerted easy and also know if something happens when I am not home.
  • For less than 1/2 the price I would buy ZWave compatible ones like these First Alert Combos for $40 https://www.amazon.com/First-Alert-Z-Wave-Carbon-Monoxide/dp/B00KMHXFAI/...