Carbon Monoxide Detector Placement – Do’s and Don’ts
Now that winter is here, the widows are closed for the duration and the furnace is set on high its time to make sure our carbon monoxide detectors are working and placed correctly to save us in the event of an emergency.
Every fuel-burning appliance in your home, including a gas furnace, produces some levels of carbon monoxide. Normally those gasses are carried out of your home, but if something goes wrong a CO leak can be life-threatening to your family. That’s why it’s so important to have carbon monoxide detectors to help warn you of excess CO in your air.
So where should carbon monoxide detectors be placed in order to best detect CO leaks in your home?
Carbon monoxide detectors placement: Do’s
In order to maximize the protection of your home from excess levels of carbon monoxide, place your detectors in all of the following places:
- On every level of your home. In order to ensure that your home has maximum protection, it’s important to have a CO detector on every floor.
- Five feet from the ground. Carbon monoxide detectors can get the best reading of your home’s air when they are placed five feet from the ground.
- Near every sleeping area. If your CO levels get too high during the nighttime, it’s important that detectors can be heard by everyone sleeping in your home. Place your detectors close enough to every sleeping area so that they can awaken everyone in the case of an emergency.
- Near attached garages. Cars produce carbon monoxide any time they are running. If you have an attached garage, those gasses can quickly spread to the rest of your house. A CO detector near your attached garage will warn you if that becomes a problem.
- Where the manufacturer recommends. Every model of carbon monoxide detector is tested according to manufacturer specifications. It’s important to take those specifications into account when you’re deciding where to place your detectors.
Carbon monoxide detectors placement: Don’ts
The following locations can either create a false alarm or avoid your detector from properly identifying the CO levels in your home:
- In close proximity to any fuel-burning appliance.
- In excessively humid areas such as your bathroom.
- In direct sunlight.
- Near any sources of blowing air such as a fan, vent or open window.
How Carbon Monoxide Is Measured
Before we get into what to look for when purchasing carbon monoxide detectors, it will help if you understand how carbon monoxide is measured.
CO is measured in a ratio called ppm (parts per million). Just as 5% means 5 out of a 100, 5 ppm means 5 out of 1 million. So, if your home has 10 ppm of carbon monoxide, there is 10 carbon monoxide molecules for every million molecules in the air.
How Much CO is Too Much?
Even in homes without gas appliances, there could be CO. So how do you know how much is too much? It depends on your age, size and health. Here are some common thresholds of carbon monoxide.
- 0.5-5 ppm – According to the Environmental Protection Agency (EPA), this is the usual range for homes without gas stoves or other gas appliances.
- Under 70 ppm – Most people have no ill effects when exposed to ranges below 70 ppm for short periods of time. Prolonged exposure (6-8) hours can cause dizziness and headaches. Also, those with heart problems may experience chest pain, according to the Consumer Product Safety Commission (CPSC).
- 100 ppm – Slight headache when exposed for 2 hours or longer.
- 150-200 ppm – Prolonged exposure at these levels often leads to disorientation and unconsciousness and can also lead to death.
Types of Carbon Monoxide Detectors
Now that you understand how carbon monoxide is measured, you’re better prepared to understand the two basic types of carbon monoxide detection devices: alarms and monitors.
Carbon monoxide alarms or detectors
These are the most common type of carbon monoxide devices. They work like your smoke or fire alarms, simply alerting you when it deems that there is a dangerous amount of carbon monoxide in your home.
However, long exposure to low levels of CO can be as dangerous as short amount of exposure to high levels. And most alarms and detectors only tell you about the high levels. That’s where the carbon monoxide monitor enters.
Carbon monoxide monitor
A carbon monoxide monitor is different because it actively monitors the amount of carbon monoxide in your air and gives you a digital readout. This lets you know when there are higher than usual amounts of CO in your home, even if they aren’t at what other alarms deem a “dangerous” level.
Which is Better?
I encourage homeowners to purchase a carbon monoxide monitor, especially if you live with young children or elderly parents, as they can be more susceptible to carbon monoxide poisoning. However, carbon monoxide monitors with digital displays can be more expensive and having an alarm or detector is better than no device at all.
Can you put a carbon monoxide detector by a thermostat¿
There is no reason that you can not place one by a thermostat.
Is it better to have one carbon monoxide detector located just outside the bedrooms or one inside each bedroom?
Have an all electric home 3 Bedroom where is. the best places to locate my carbon monoxide alarms
I have a wood burning fire place, do i need to put a carbon detector near that? If not how far away from the fire place should it be? We have them by our bedroom and garage as well.
We have electrical base heating in condo. Also have gas fireplace used a lot in winter.
How far away from fireplace should co2 unit be placed
There is no hard and fast rule, but I would place it outside the bedroom area so it can be clearly heard at night.
It says "5 feet from the ground." Do they mean 5 ft from the FLOOR? Or the ground outside?
Its five feet from the floor of the house your standing on.
Come on Heather, what kind of question is that?
LOL! SERIOUSLY?
Your kidding right? Yes, the floor would be correct!
I’ve got one above a high level gas cooker and it goes off every time I put the grill on is that right???
Yes – move the detector.
Smoke detectors are placed high in a room and CO detectors are placed 5 feet from the floor. Where does a combination smoke detector/CO2 detector get placed?
Always follow the manufacturers recommendations, they have done all of the testing for their own device and know how it operates best.
5 feet from the ground refers to minimum height, it is perfectly ok to put it on the ceiling.
Very good article. Well organized and to the point with references. I enjoyed reading it and learned from it. Thank You.
Thank You
I agree w Raymond Marek, this was a super informative article. We recently installed gas heating, I was totally against it but my husband was insistent on the pros of heating w gas. We have only had our gas furnace for a couple weeks after reading this article I feel much more comfortable in my home, so to you I say thank you Sir for giving me some peace of mind by writing your article
My plug in are not 5’ from the floor ?
That’s okay! Its more important where they are placed than the exact height. Make sure the CO detector is located in close proximity (on the same floor) as the sleeping areas so that an alarm can be heard when sleeping.
I recently purchased a house that is only a couple of years old. It already has smoke detectors in the appropriate areas. I feel I should also have a CO detector since I have a gas stove? Do I replace the regular smoke detector near the kitchen or install it in a different way? Thanks.
I was an electrical contractor for 38 years, and although as these devices first came out they were always on the combination smoke/CO2 devices, which meant they were mounted within 12″ of the ceiling or on the ceiling, at least 3 feet from an air duct. That said, on one project about 15 years ago the job required a fire marshal to approve the install of this plus the fire detection system due to the fire hazard area. He laughed when he saw my placement of the combo unit and said he would approve it, because it was a combo unit. Then he added that famous quote, “Do you know how CO2 leaks affect people when the CO2 actually reaches those detectors?” Of course not, I said. He explained the heavier than air feature and said, the CO2 detector should be a separate unit and placed near the floor, some 12-18″ above it.
That said, I always from then on, bid the job with separate units. The general contractor was in agreement, beings he was standing there when the fire marshal spoke.
But I do have a question, honest. Now retired and the electrical code keeps changing… and frankly, I am not trying to keep up on it, but I am working on my own home. I am remodeling two bedrooms and a bathroom to become one master suite with both in one area. I am putting in a CO2 detector, but after reading your blog, though it would be in the bedroom with a door between it and the bathroom; I am a widower, so I doubt I will close the bathroom door to take a shower, shave and such. Will this detector on the outside of this bathroom be affected by the steam (even if I have a humidity switch)? Should I abandon this location and put it on the wall just outside the bedroom in my living room?
I would always follow the manufacturers recommendations for their particular device, after all they are the ones who know how their device will operate best. That being said I would avoid the humid area directly adjacent to the bathroom and opt for a location in the bedroom or hallway directly outside of the bedroom depending on where you have power for the device.
The combo units are Smoke / CO units not Smoke / CO2 units.
CO2 sinks, CO rises. I’m not sure if that comment was a slip of the wrist so to speak but the Fire Chief’s comment reflects that he/she was talking about CO2. Different issues I would say.
I can’t think of a reason one would need a CO2 detector in a residential home but I’m sure they exist as do the detectors themselves.
Interesting blog you’ve made that I came across whilst googleing the correct placement of a combination CO / Smoke detector. Thought I would speak up and note the difference as these types of information platforms have far reach.
Its CO not CO2
Outstanding article Alan. I learned from it and thank you. Excellent work
Hi Alan I am Electrical inspector and your info is right on. I enjoyed reading all the questions and your comments. You are providing people with good advice. I can’t stress enough to follow these simple steps. Follow the manufacturers instructions. Placement is very important as well as effective for early warning. Always check with the local authority having jurisdiction.
Hi John:
Thank you for the kind words. You are 100% correct in saying “Follow the manufacturers instructions. Placement is very important as well as effective for early warning”. Each manufacturer tests their own equipment and sets guidelines (instructions) for the most effective and safest place to install their devices, and its not always the same as a different manufacturer. Most important of all is that we have carbon monoxide alarms installed in our homes – many homes do not!
I agree! Carbon monoxide is a colorless, odorless, tasteless gas produced by burning gasoline, wood, propane, charcoal or other fuel. Improperly ventilated appliances and engines, particularly in a tightly sealed or enclosed space, may allow carbon monoxide to accumulate to dangerous levels.
The core function of the smart smoke detector remains the same; they’ll notify you when they recognize the presence of smoke. But that’s where the similarities stop, because smart detectors can offer a whole lot more.