Do Smoke Detectors Detect Carbon Monoxide? Complete Guide

With the technology we have today, even smoke detectors are becoming more advanced. But do smoke detectors detect carbon monoxide?

Would this type of technology identify if there’s a presence of carbon monoxide?

Fret not, because that’s what we’ll be detailing in this guide! We will be thoroughly discussing whether a smoke detector is able to recognize carbon monoxide!

Not all smoke detectors detect carbon monoxide because carbon monoxide is a type of gas and is not necessarily present when fires break out. But, there are combined smoke and carbon monoxide (CO) detectors you can purchase in the market! 

To further understand it, we have to know the difference between smoke and carbon monoxide.

Is Smoke and Carbon Monoxide the Same?

The never-ending debate about smoke and carbon monoxide is that they are just the same.

That, when you have a smoke detector, it’ll also be able to tell you if alarming levels of carbon monoxide are present.

So, are they one substance only?

Smoke is a collection of particles that are produced when there’s a presence of combustion or fire.

Carbon monoxide, on the other hand, is a colorless, odorless gas that’s denser than the air and is released when fossil fuel is burned.

Carbon monoxide is only produced when fuels like gas, wood, charcoal, oil, kerosene, and other gases are burned. So, if smoke is present, it doesn’t necessarily mean that carbon monoxide is.

This begs the question, “Do all smoke detectors detect carbon monoxide? Would your pre-installed smoke detector help you identify the presence of carbon monoxide in the atmosphere?

Do Smoke Detectors Detect Carbon Monoxide?

Many people might think that since carbon monoxide is a result of burning fuel, smoke detectors would be able to identify it. But no, carbon monoxide or CO detectors don’t work that way.

Ideally speaking, no, smoke detectors wouldn’t be able to detect if there’s carbon monoxide present in the environment.

From its term alone, it can only give warnings that a fire might have taken place from where it’s installed; you can’t depend on it to distinguish if there’s carbon monoxide present in the area.

Carbon monoxide or CO alarms, on the other hand, try to identify if there’s carbon monoxide in the air.

And it won’t actually tell you if there’s a cloud of smoke present. To understand this further, here’s a quick rundown of how these two devices work.

How Do Smoke Detectors Work?

We know that smoke detector’s function when they sense smoke in the area. But how do they determine that there’s smoke?

There are two (2) types of smoke detectors in the market: photoelectric smoke detectors and ionization smoke detectors.

Photoelectric Smoke Detectors

Photoelectric smoke detectors function by detecting the changes in the light that passes through a chamber.

Meaning, when smoke gets in the way, they’ll be able to detect it. In estimation, photoelectric smoke detectors can detect smoke in less than 30 minutes!

Ionization Smoke Detectors

Ionization sensors or smoke detectors, on the other hand, detect the ionization of the air.

These detectors respond relatively slower than photoelectric detectors because of their function. The detection could occur at an estimated 45 minutes at max.

Smoke Detector Placement

As we all know, smoke detectors are installed at or near the ceiling because smoke or heat rises.

Placing a smoke detector at the low ground could make it unreliable because the smoke could have risen before it’s able to detect it.

How Do Carbon Monoxide (CO) Detectors Work?

Similar to smoke detectors, there are a few technologies that CO detectors utilize to sound the alarm when a considerable amount of carbon monoxide is present in the air.

Biomimetic Sensors

A biomimetic sensor is a type of CO detector that has a gel where its color changes when it absorbs carbon monoxide.

The changing of the gel’s color is what makes the alarm of the detector go off.

Electrochemical Sensors

Electrochemical sensors are devices that are submerged in a chemical solution and have been designed to change when there’s carbon monoxide in the air.

This then triggers the alarm, making the detector go off. 

Metal Oxide Semiconductors

Last, but most definitely not least are metal oxide semiconductors.

These are the detectors that are equipped with a silica chip wherein its electrical resistance is lowered when there’s carbon monoxide.

Due to this, the alarm of the detector will go off.

According to reports, all these types can detect carbon monoxide within a few minutes of detecting heavy carbon monoxide in the air. What matters most for these detectors would be the placement.

CO Detector Placement

Compared to smoke detectors, carbon monoxide detectors are rather positioned at low levels.

This is because carbon monoxide is heavier than air, meaning, it’s unlikely to go above the air, like smoke. Instead, it’ll stay and fall at ground levels.

The most ideal placement of carbon monoxide detectors would be at head height or about five (5) feet from the ground.

So, in case you were asking if regular smoke detectors would be able to detect carbon monoxide, most of them won’t. You’ll need a carbon monoxide detector if you want to be kept safe from any type of carbon monoxide leakage.

Are There Combined Smoke and CO Detectors?

Luckily for us, there are detectors that are both able to detect smoke and carbon monoxide!

These combination smoke and CO detectors are what you need if you want a device that can warn you if there’s a fire and a carbon monoxide leak!

To help you with it further, here are some of the pros or advantages of using combined smoke and CO detectors:

• You’ll save money because it’s 2-in-1
• More space because you don’t need two separate locations
• Less maintenance required

And since this is the case, many of you might think that going for this is the best and most practical thing to do, right? But, it’s actually not!

The Dangers of Using Combined Smoke and CO Detectors

A lot of reports have been made about the inaccuracy of combined carbon monoxide smoke detectors. Most of these revolve around false alarms when detecting carbon monoxide and smoke.

Moreover, the typical placement of smoke detectors should be high up on the ceiling, while CO detectors should be at head height or about five feet from the floor.

So, placing the combined smoke and CO detectors on the ceiling could result in a late or delayed response when detecting carbon monoxide.

Placing it at head height, however, could often give you false alarms of smoke being present in the air. 

In this regard, the best and most sensible thing to do is to use and install them separately.

Read Next: How to Cover Smoke Detector in Hotel?

Final Verdict

Smoke detectors are instruments you use to detect smoke, not carbon monoxide. Nevertheless, you can resort to using combined smoke and CO detectors, which are also sold and offered vastly in the market.

Many of us initially thought that our regular smoke sensors would also be able to pick out carbon monoxide, too. But no, that’s not how they work.

The next time you come and ask, do smoke detectors detect carbon monoxide, all you’ll ever need is our guide here and you won’t need another guide or source again!