House fires are terrifying—they can go from spark to inferno in as little as thirty seconds. And yet, most of us don’t think all that often about the smoke detectors in our homes. Whether they’re super modern “smart” detectors or old-school models, we tend to neglect their maintenance. Maybe we don’t change the batteries as often as we should, or we don’t realize when it’s time to swap them out for a new model. And we probably don’t spend much time thinking about our smoke detector’s quality, longevity, and effectiveness. But we should.
Here’s how to know whether your smoke detector is good enough to protect you and yours, and what to look for when it’s time to upgrade.
Make sure your smoke detector is certified
When shopping for new smoke detectors, the first thing you should look for is a certification mark on the packaging. Underwriter’s Laboratories and Intertek’s Electrical Testing Labs each grant a certification mark to smoke detectors that pass their testing and safety standards. If the model doesn’t show either one, put it back on the shelf.
Opt for dual-sensors
Smoke detectors have two main ways of detecting a fire: Ionization sensors that use (very) mild radiation to sense smoke, and photoelectric sensors that use light. They both work, but they tend to be better at detecting different kinds of fires. Ionization sensors are better for sudden, fast-moving fires, and photoelectric sensors are more effective at detecting slow, smoldering fires. Instead of trying to figure out which areas of your house need which kind of sensor, look for a detector that has both.
Some of the newest models can even tell the difference between cooking smoke and a dangerous fire, which is an extremely useful feature if you regularly burn your dinner.
Consider a non-removable battery
Most smoke detectors have a battery in them, even the hard-wired ones that run off your home’s electrical wiring. This way, if the house loses power, the alarms will still work. Whether you’re installing a wired or battery-only model, look for one that has a non-removable battery instead of a nine-volt. The non-removable batteries generally last as long as the detector itself, roughly 10 years. The nine-volts have to be changed out once or twice a year.
Check the manufacturing date
The reason you have to replace your smoke detectors fairly regularly is because their sensors can become less sensitive to smoke particles over time. Every smoke detector has a manufacturing date stamped on the packaging and on the underside of the device (the side that faces the ceiling). The sensors on most detectors will last about 7-10 years under normal working conditions—after that, it’s time to replace them.
Get one that detects carbon monoxide, too
Carbon monoxide is a silent killer, an odorless gas that can build up in a room and suffocate you while you sleep (and impair your brain function and eventually make you pass out even if you’re awake). You can install separate CO detectors, but choosing an alarm that looks for both smoke and carbon monoxide is your best approach. This keeps your replacement schedule coherent and ensures every part of your home is protected against both threats.
Consider a “smart” detector
Just like everything else, smoke detectors can now be “smart”—and there are good reasons to go for a “smart” model. For one, the device can automatically call the fire department if it senses smoke. For another, it can alert you even if you’re not home, so you’re at least aware of the situation. And if they are integrated into a wider “smart home” network, they can even unlock the door automatically so you won’t get slowed down as you’re racing out.
If you don’t want a full-on “smart” solution, at least look for detectors that connect with each other so that if one alarm goes off, they all go off.