How a Carbon Monoxide Detector Works (and Why You Can’t Do Without One)

Did you ever hear the classic Reddit tale of the paranoid guy who thought his landlord was breaking into his apartment to leave notes?

Turned out the poor fella just had a case of long-term carbon monoxide exposure. He was leaving himself notes. He just couldn't remember it because of the CO he'd been breathing.

He’s lucky that he came out of it with nothing worse than a creepy tale, because carbon monoxide is deadly. At Reviews.org, we recommend always having a working carbon monoxide detector in your home to protect you and yours. But … how do they even work?

Let’s do a quick FAQ about why you need a carbon monoxide detector in your home.

There are three kinds of carbon monoxide detectors: electrochemical, metal oxide semiconductor, and biomimetic.

An electrochemical carbon monoxide alarm uses electrolytes for its early warning system. When carbon monoxide touches the electrolyte, a chemical reaction sets off the alarm.

An alarm that uses a metal oxide semiconductor depends on electrical circuitry. The contact with carbon monoxide completes a circuit that sets off the alarm.

Finally, a biomimetic sensor uses gel that mimics the hemoglobin in your blood. If the gel absorbs too much CO, the alarm goes off. Cool, right? We think it sounds like something from a sci-fi novel, but it’s 100% real.²

Regardless of the tech used, all three types will sense a carbon monoxide leak long before you’re in danger.

Any functional CO detector is a good CO detector. But if you suffer from analysis paralysis, here are a few we recommend.

Not every carbon monoxide detector includes a smoke alarm and vice versa. Make sure you know what your detector includes, just in case you need to install a separate one for smoke.

Also, think hard about what types of detectors you need and where. Because CO rises, most folks opt for hardwired or battery-dependent ceiling installs. But that doesn’t mean you can’t use a plug-in model; you’ll just want to think hard about when and where to place it.

That depends on the kind of detector you buy.

If you buy a portable, battery-based detector, you just need to pop in some batteries, set the detector in your room of choice, and then run any required tests.

If you buy a plug-in detector, you only have to plug it in, then test it.

But if you’re buying a detector that goes on the ceiling, it’s a little more complicated. We’re no electricians, so we can’t take you on a step-by-step (although your alarm instructions should be able to). But here’s a general idea of steps you’ll likely take.

1. Select a location. The National Fire Protection Association recommends CO alarms in every bedroom but suggests you follow manufacturer instructions to determine exact placement.
2. If installing a hardwired alarm, install a ceiling box to house the wires.
3. Screw the mounting bracket into the ceiling.
4. Wire the alarm or install fresh batteries.
5. Attach the alarm to the mounting bracket.
6. Run the tests as instructed by the manufacturer.

Not for the faint of heart, especially when it comes to wiring. If you don’t have much electrical experience and don’t feel comfortable attempting the wires, ask someone more knowledgeable to do it for you.

So what did we learn today about carbon monoxide and carbon monoxide detectors? Well …

• Why do you need a carbon monoxide detector? To warn you about carbon monoxide poisoning.
• How does a carbon monoxide detector work? There are various ways, but in the end, they all provide early warning about the dangers of carbon monoxide gas.
• Which carbon monoxide detector should I choose? Whichever one best suits your needs.
• How do you install a carbon monoxide detector? It varies, but keep in mind that a wired installation is not for everyone.

Sources