How many carbon monoxide detectors do you need in a house

Carbon monoxide is a deadly gas that can build up quickly in closed spaces. It’s important to have detectors installed in your house so that you can be warned if there is any danger of carbon monoxide poisoning. So, how many carbon monoxide detector do I need in my house?

Table of Contents Show

What the type of detector should I need to install
Where to install the detector
How many detectors should I need in the house
Privacy & Transparency
The General Requirements
State Specific Requirements
Recommendations and Useful Links
Where in the home should carbon monoxide detectors be placed?
Where should a carbon monoxide detector be placed high or low?
Is it better to have separate smoke and carbon monoxide detectors?

The number of carbon monoxide detectors you need in your house depends on the size of your house and how many rooms there are. The recommended number of detectors is one per floor, but you may also want to install them in specific rooms where people spend a lot of time, like the living room or bedroom. Carbon monoxide detectors should be installed in a location where they will get good air flow, like near the ceiling or in a hallway. Below, I’ll detail where to install carbon monoxide detectors in your house, what type of detectors you need, and the optimal number of detectors in your home.

What the type of detector should I need to install

When installing detectors in your home, it’s important to know which type of detector you need in each room. For example, bedrooms need carbon monoxide detectors, and kitchens need smoke alarms and carbon monoxide detectors.

So, which type of detector should you install in every room of your home? Here are suggestions:

– In the kitchen: install smoke alarms and carbon monoxide detectors. It is easy to accumulate carbon monoxide and start a fire when using kitchen utensils. For safety reasons, it is best to install two kinds of detectors.

– In bedrooms: install carbon monoxide detectors. In many cases people have died from carbon monoxide inhalation in deep sleep, so carbon monoxide detectors must be installed in bedrooms.

– In the living room: install a smoke alarm. Due to the ventilation in the living room, the concentration of carbon monoxide will basically not become high, so you only need to install a smoke alarm.

– In the basement: install carbon monoxide detectors, smoke alarms and water detectors. When the car is started in the basement, a small amount of carbon monoxide will accumulate. In addition, some people store their items in the basement. Over time, a lot of dust will accumulate on the surface of the cargo, and once it encounters a fire, a fire will occur; some basements will accumulate due to rain. Water, so need to install water sense.

– In the bathroom: install a carbon monoxide alarm. The bathroom is generally equipped with a heater. Due to the high temperature, small space and poor ventilation during the bathing process, it is not a good thing for people who take a bath for a long time to stay in the bathroom for too long. And fainted in the bathroom.

– In hallways: install smoke alarms and carbon monoxide detectors.

Now that you know which type of detector to install in each room, be sure to take the necessary steps to keep your family safe!

Where to install the detector

The installation position of carbon monoxide is on the wall about 1 meter away from the ceiling. Because carbon monoxide is lighter than air, it will float upward. At the same time, the carbon monoxide detector is equipped with a display screen, which can be installed on the wall to make the display number parallel to people’s line of sight.

The smoke detector is installed on the ceiling. First of all, the smoke is floating upward, which makes it easier to detect smoke particles when installed on the ceiling; Secondly, the smoke detector has no display screen, so it does not need to be installed on the wall. Installing it on the ceiling can also increase the measurement range.

How many detectors should I need in the house

Carbon monoxide alarms should be installed on every floor of your home, including the basement. It needs to be installed inside every bedroom and outside every sleeping area. For example, a three-bedroom, two-story home should have at least seven carbon monoxide alarms. Homes with a certain number of hardwired alarms can still place additional battery-operated smoke alarms throughout the house. If there are not many smoke alarms in the house, just install it in the key areas of the bedroom, kitchen and bathroom.

Privacy & Transparency

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Carbon monoxide is one of the biggest dangers in your home, yet it’s barely detectable. So, it’s important to monitor it at all times.

But how many carbon monoxide monitors do you need? As a general rule, a carbon monoxide alarm is required on every floor of a home, including a basement. For example, a 2-story home with a basement will need 3 carbon monoxide detectors or more. However, there are some variations, including the layout of your home, whether you have an attached garage, how your ventilation systems are connected, and specific state law requirements.

The General Requirements

Most states have adopted something called the International Residential Code (specifically, Section R315), with new states being added each year. In basic terms, R315 requires a carbon monoxide detector on each level of a home where both the sleeping areas and carbon monoxide hazards coexist, such as a shared ventilation system, attached garage, or fuel-burning appliance.

The states that have adopted this code generally require the detector to be within 10 to 20 feet of the sleeping areas (measured from the door of each room). If a room has a fuel-burning appliance, however, it will need to have its own carbon monoxide detector inside the room itself.

The code also requires a detector on the basement level, although most states don’t count the lower level of a split level home. Attics require a detector only if they have living space.

There are some nuances and exceptions, so you’ll still need to research the specific laws in your own state.

You’ll also have to research what kind of carbon monoxide detectors are allowed. Some states require a hardwired detector, others are fine with a battery-operated one. Some allow a smoke/carbon monoxide alarm combo, others don’t.

In recent years, some states have also adopted legislation to require each carbon monoxide detector to have a 10-year sealed battery, so you’ll have to search for the most recent laws in your state to stay current. In my opinion, it’s wise to buy them anyway since the trend seems to be in that direction.

NOTE: This post primarily discusses single-family and dual-family residential units. The research here may not apply for other types of buildings.

State Specific Requirements

Alaska

Law: AS 18.70.095(a).
One alarm required at minimum; must follow manufacturer’s instructions.
Read more about this state’s recommendations.

Alabama

Has adopted the International Residential Code (Section R315), which:
- Requires one alarm near each sleeping area and one alarm per floor overall, including the basement, but excluding attics and crawl spaces in all homes that:
  - Have an attached garage or fuel-burning appliance on the same floor as the sleeping area.
  - Have sleeping areas that are connected to the fuel-burning appliance or attached garage through the ventilation system with.
All residential homes that don’t fall in the above description are required one common alarm per home.
Read more about this state’s recommendations.

Arizona

No specific state law exists as of writing this post, but many individual cities in Arizona have their own requirements in place. If they do exist on a city level, they usually follow the International Residential Code.

Arkansas

Law: AR 20-7-138.
Requires an alarm on each level of the home. Cannot be more than 3 feet from the floor and can’t be directly near garages, furnace rooms, and bathrooms. It appears that this code is only pertinent to new construction homes at the moment.
Read more about this state’s recommendations.

California

Law: CBC 907.2 and CRC 314/315.
Follows the International Residential Code. Generally requires an alarm outside or near the general sleeping area, but you may also need to install a carbon monoxide alarm in each room. Fine of $200,000 if not followed.
Read more about this state’s recommendations.

Colorado

Law: Lofgren and Johnson Families Carbon Monoxide Safety Act.
Follows the International Residential Code, with each detector having to be within 15 feet of each sleeping area.
Read more about this state’s recommendations.

Connecticut

Law: Public Act 13-272.
Requires all homes built after 2005 to have one or more alarms. No notable specifics, except that you must follow manufacturer’s instructions.
Read more about this state’s recommendations.

Delaware

Law: Title 16, Chapter 66C, Section 6602C.
Follows the International Residential Code.
Read more about this state’s recommendations.

Florida

Law: Title 33, Chapter 553, Section 553.885.
Follows the International Residential Code, where each carbon monoxide detector must be within 10 feet of each sleeping room. Currently only applies to homes and alterations/additions built after 2008.
Read more about this state’s recommendations.

Georgia

Law: Title 8, Chapter 2, Section 20.
Homes built after 2009 must have at least one detector near the sleeping area, following the International Residential Code.
Read more about this state’s recommendations.

Hawaii

No law exists as of now.

Idaho

Law: Idaho Fire Code, Chapter 9, section 908.7.
Follows the International Residential Code. Each home must have one detector minimally, and near sleeping areas provided they are on the same level as a fuel-burning appliance or share the ventilation system with it. Detectors must be UL 2034 compliant and follow NFPA 720 guidelines.
Read more about this state’s recommendations.

Illinois

Law: Illinois Smoke Detector Act (425 ILCS 60).
Follows the International Residential Code. Specifically, must have a detector within 15 feet of any sleeping area, with one detector at minimum per story, including the basement. Illinois also requires all homes to have carbon monoxide detectors with sealed 10-year batteries by 2023.
Read more about this state’s recommendations.

Indiana

Indiana has no state law requiring carbon monoxide detectors, and the local municipalities that require them are often blocked by special interests in the construction industry. Check your local laws as there may be existing ordinances that require carbon monoxide detectors.

Iowa

Law: Administrative Code Chapter 661- 211.
Follows the International Residential Code, but primarily states to place a carbon monoxide detector near a sleeping area only.
Read more about this state’s recommendations.

Kansas

No law exists as of now.

Kentucky

Law: Kentucky Building Code, Chapter 9, Section 915.
Requires one or more carbon monoxide detectors near the sleeping area, following the International Residential Code.
Read more about this state’s recommendations.

Louisiana

Law: Title 17 (Uniform Construction Code), Part 1, Section 107.
Requires one or more carbon monoxide detectors near the sleeping area, following the International Residential Code.
Read more about this state’s recommendations.

Maine

Law: Title 25, Chapter 317, Section 2468.
Newer homes must have at least one detector near the sleeping area, following the International Residential Code. Also requires that each carbon monoxide have a sealed battery with a 10-year life.
Read more about this state’s recommendations.

Maryland

Law: Title 8, Chapter 2, Section 20.
Homes built after 2009 must have at least one detector near the sleeping area, following the International Residential Code.
Read more about this state’s recommendations.

Massachusetts

Law: 527 CMR, Section 13.7.6.5.
Follows the International Residential Code. Each level of the home must have an alarm, regardless of whether there is a sleeping area on each level. In addition, all alarms have to be within 10 feet of sleeping areas.
Read more about this state’s recommendations.

Michigan

Law: Act 230, Section 125.1504f.
Following the International Residential Code. Requires a detector near sleeping areas, but also near attached garages and fuel-burning appliances.
Read more about this state’s recommendations.

Minnesota

Law: Minnesota Statutes, Chapter 299F, Section 51.
At least one detector within 10 feet of each sleeping area, following the International Residential Code.
Read more about this state’s recommendations.

Mississippi

Law: N/A.
Newer and existing homes must have at least one detector.

Missouri

Law: N/A.
Newer and existing homes must have at least one detector.

Montana

Law: Montana Carbon Monoxide Detector Standard (24.320.301).
Must have one detector near each sleeping area, following the International Residential Code.
Read more about this state’s recommendations.

Nebraska

Law: Nebraska Carbon Monoxide Safety Act
Must have one detector on each level of a home, although it doesn’t specify anything about placement near sleeping areas.
Read more about this state’s recommendations.

Nevada

Law: N/A.
Detector is required in and outside of each sleeping area, and overall at least one unit is needed on each level of the home, including the basement. Follows the International Residential Code.
Read more about this state’s recommendations.

New Hampshire

Law: New Hampshire Revised Statutes, Title 12, Chapter 153, Section 10-a.
Follows NFPA 720. Just like R315, it also requires a detector on each level of a home, including basements, and near sleeping areas.
Read more about this state’s recommendations.

New Jersey

Law: Annotated Statutes, Title 52, Chapter 27D, Section 133.3.
Must have at least one detector near the sleeping area and on each floor, following the International Residential Code. Homes built before 1977 must have a detector with a 10-year sealed battery, while newer homes must all have hardwired detectors.
Read more about this state’s recommendations.

New Mexico

Law: N/A
Follows the International Residential Code, so you’ll need to install a detector near on in the sleeping areas.
Read more about this state’s recommendations.

New York

Law: Standards for New York State Uniform Fire Prevention and Building Code (Section 378)
Must have at least one detector near the sleeping area, following the International Residential Code.
Read more about this state’s recommendations.

North Carolina

Law: North Carolina Residential Code, Section R315.
Must have at least one detector near the sleeping area, following the International Residential Code.
Read more about this state’s recommendations.

North Dakota

Law: North Dakota Administrative Code, Chapter 24.1-06-01, Section 40.
Must have at least one detector near the sleeping area, following the International Residential Code, installed according to NFPA 720 standards.
Read more about this state’s recommendations.

Ohio

Law: Ohio Fire Code, Section 915.
Homes must have at least one detector near the sleeping area, following the International Residential Code. All detectors must be UL 2034 listed and hardwired. Can do smoke/carbon monoxide combination detectors.
Read more about this state’s recommendations.

Oklahoma

Law: Oklahoma Statutes, Title 74, Section 324.11d.
Homes must have at least one detector near the sleeping area, following the International Residential Code. Detectors must be hardwired.
Read more about this state’s recommendations.

Oregon

Law: 2017 ORS, Volume 12, Chapter 476, Section 476.725.
Law defers authority to the State Fire Marshall. Requires to install alarms within 15 feet of sleeping areas, although it doesn’t specifically state to require an alarm inside each bedroom on their website (assuming the room has a fuel-burning appliance), and it doesn’t require an alarm on each level, either. Detector can be hardwired, battery-operated, or smoke/carbon monoxide combo alarms.
Read more about this state’s recommendations.

Pennsylvania

Law: Carbon Monoxide Alarm Standards Act.
As of writing this, law only exists for existing multi-family units and when a residential building is sold. Detector must be UL 2034 listed and installed according to NFPA 720 standards.
Read more about this state’s recommendations.

Rhode Island

Law: Fire Safety Code (Found in Rhode Island General Assembly, Chapters 23 – 28).
Must have a carbon monoxide monitor near sleeping areas, according to the International Residential Code. Except for homes built between 1977 and 2001, the detectors must be interconnected. Homes built after 2002 must be hardwired and have a battery backup. Homes built after 2013 must have carbon monoxide detectors that are installed following NFPA 720 standards.
Read more about this state’s recommendations.

South Carolina

Law: State Marshal Policy 14-001.
Must have at least one detector near the sleeping area, following the International Residential Code. Can use a smoke/carbon monoxide dual combo alarm, but must be installed according to NFPA 720 standards.
Read more about this state’s recommendations.

South Dakota

Law: SDRLC Rule 46:04:01:20.
Each home must have at least one detector, including at least one detector per story (basement included).
Read more about this state’s recommendations.

Tennessee

Law: Tennessee Code, Title 68, Chapter 120, Sections 101 and 112.
Homes built after 2016 must have at least one detector within 10 feet of the the sleeping area, following the International Residential Code. Detector must be hardwired and have a battery backup. Homes built prior to 2016 need at least one carbon monoxide detector in the home. It can either be hardwired and/or battery operated.
Read more about this state’s recommendations.

Texas

Law: N/A.
Not required by the state, although some local city ordinances exist that make carbon monoxide detectors a must.
Read more about Austin, TX ordinance recommendations.

Utah

Law: Utah Code, Chapter 5, Part 1, Section 15A-5-204.
Carbon monoxide detectors are required on each level. All alarms must be interconnected. New construction homes must have hardwired alarms with a battery backup. All alarms must be UL 2034 compliant and installed according to NFPA 720.
Read more about this state’s recommendations.

Vermont

Law: Vermont Statutes, Title 9, Chapter 77, Section 2882.
Must have at least one detector near the sleeping area, following the International Residential Code. All detectors must follow NFPA 720 and NFPA 101 guidelines and can be hardwired and/or battery-operated.
Read more about this state’s recommendations.

Virginia

Law: Administrative Code, Title 13VAC5, Chapter 63, Section 240.
Must have at least one detector near the sleeping area and on each level, following the International Residential Code. Must be UL 2034 compliant and installed following NFPA 720.
Read more about this state’s recommendations.

Washington

Law: Washington Administrative Code, Title 51, Chapter 51, Section 315.
One or more carbon monoxide detectors are required near the sleeping area, following the International Residential Code. Detector must be UL 2034 compliant. May use smoke/carbon monoxide combo alarms.
Read more about this state’s recommendations.

West Virginia

Law: West Virginia Code, Chapter 29, Article 3, Section 16A.
Each home must have at least one carbon monoxide detector, which must be hardwired and have a battery-backup.
Read more about this state’s recommendations.

Wisconsin

Law: Title 8, Chapter 2, Section 20.
Homes built after 2009 must have at least one detector near the sleeping area, following the International Residential Code.
Read more about this state’s recommendations.

Wyoming

Law: Title 8, Chapter 2, Section 20.
Carbon monoxide detectors must be installed in the basement and each other level of a home, within 21 feet of each sleeping area. Must be installed on every level, even if there are no sleeping areas. Must be hardwired, have a battery backup, and be UL 2034 compliant.
Read more about this state’s recommendations.

Recommendations and Useful Links

NFPA 720 Installation Standard Explained
UL 2034 Product Standard Explained
2018 International Residential Code (if you’d like a hard copy or ebook)
Kidde Carbon Monoxide Detectors:
- Hardwired, interconnected version with battery backup.
- Plug-in version with a 10-year sealed battery.

DISCLAIMER: The above is my cursory research only and may not be entirely accurate or detailed. It should not be used as advice, but rather to guide you to the resources necessary to find out the full and most current information. You should also go beyond the state level and research local rules and regulations as those may have stricter requirements.

Where in the home should carbon monoxide detectors be placed?

At a minimum, industry experts recommend a CO alarm be installed on each level of the home -- ideally on any level with fuel burning appliances and outside of sleeping areas. Additional CO alarms are recommended 5-20 feet from sources of CO such as a furnace, water heater or fireplace.

Where should a carbon monoxide detector be placed high or low?

Standalone carbon monoxide alarms are often placed low on the wall because they need to be plugged into an outlet that's near the floor. CO alarms can also have a screen that shows the CO level and needs to be at a height where it's easy to read.

Is it better to have separate smoke and carbon monoxide detectors?

Although they may look and sound similar, CO alarms and smoke alarms are designed and intended to detect two separate, distinct hazards. Therefore, to help protect your family from both hazards, it's important to install both UL Listed CO alarms and smoke detectors.