Carbon monoxide and smoke detector types and where to install them
Carbon monoxide and smoke detectors keep watch over homes at relatively low cost and are generally easy to install. Different types have been introduced over the years, creating more variety in price points and capabilities. Keep reading to learn about their differences and where best to install them.
What are carbon monoxide detectors
Carbon monoxide (CO) is a poisonous gas that can be emitted from fuel-burning appliances like stoves or fireplaces. Colorless and odorless, it can cause death or illness when breathed in at high concentrations. [1] A carbon monoxide detector uses sensors to alert residents in a home when the gas is present.
Types of carbon monoxide detectors
Battery-powered CO detectors
Battery-powered carbon monoxide detectors run without having to rely on your home’s power. They can be placed with greater flexibility than plug-in models, monitoring areas of your home without access to outlets. Their batteries also ensure they continue to operate even when your home loses power. Compared to other types of CO detectors, battery-powered tend to be less expensive. [2]
Plug-in CO detectors
Plug-in carbon monoxide detectors run off your home’s electricity, although many models also come with a battery backup in case your home loses power. These detectors are easy to install, and many come with digital displays that read CO concentration for more precise testing. [2]
Combination CO/smoke detectors
Combination detectors have a dual purpose - alerting residents to the presence of both CO and smoke. These models can be battery-powered, plug-in or hardwired into your home and may save money you would have otherwise spent on two separate detectors. [2]
Where to install carbon monoxide detectors
Carbon monoxide detectors should be dispersed strategically around your home; it’s advisable to have one on each floor for complete coverage. Here are a few good places to install them:
- Near sleeping areas – It’s critical your carbon monoxide detectors can wake you up if dangerous concentrations are detected at night. Placing detectors inside bedrooms or just outside may help.
- Near the kitchen – Fuel-burning kitchen appliances can emit carbon monoxide, so placing a detector nearby is a good way to catch it at the source. To avoid false alarms, place it about 15 feet or more from those appliances. [3]
- Near the garage – Vehicles produce carbon monoxide. If your home has a room over the garage, consider placing a carbon monoxide detector there to catch gas leaking up from below. [3]
- In the basement – Some appliances found in basements like laundry machines and water heaters can emit carbon monoxide. A detector placed in this area can help catch it if they do. [3]
What are smoke detectors
Smoke detectors are an essential part of every home safety plan, testing the air for particulates and alerting occupants of a building when there’s a chance of fire. According to the National Fire Protection Association, working smoke detectors in your home can reduce the risk of fire–related death by 55%. [4]
Types of smoke detectors
Photoelectric smoke alarms
Photoelectric smoke detectors use light to detect the presence of smoke. When smoke goes inside the detector, an internal light source is disrupted, scattering light onto a photosensitive cell. When the cell detects this change in the light, the alarm sounds. [5]
Ionization smoke alarms
Ionization smoke detectors contain an internal electric current that can be disrupted by smoke. When the current is disrupted, the alarm sounds. [5]
Ionization vs photoelectric
Different types of smoke detectors are better at responding to different kinds of fire. Photoelectric alarms tend to be better at detecting gradually burning, smoldering fires, while ionization alarms are often better at detecting fires with larger flames. Ionization detectors may also be less expensive than photoelectric. For more complete protection, it’s a good idea to keep both types in your home. Dual sensor variations are available that house both detector methods in the same unit. [5]
Where to install smoke detectors
Smoke detectors should be placed on every floor of your home. Install them inside and outside of sleeping areas, in your basement and in rooms next to staircases that lead to upper floors. Alarms should be installed at high elevation to account for smoke’s tendency to rise. Place them either on ceilings or on the wall within 12 inches of the ceiling. [5]
Protecting your home
As technology improves, knowing how and where to install smoke alarms and CO detectors is just the beginning. Smart home systems can connect devices like these to your phone, even alerting emergency services on your behalf. With more advanced technology increasing the protection available to your home, learning the basics of each device can keep you and your family that much safer.
Sources:
[1] “What about carbon monoxide detectors?” epa.gov/indoor-air-quality-iaq/what-about-carbon-monoxide-detectors (Accessed March 2025)
[2] “Types of Carbon Monoxide Detectors: A Definitive Guide,” getsafeandsound.com/blog/types-of-carbon-monoxide-detectors/ (Accessed March 2025)
[3] “How to place, install carbon monoxide detectors in your home,” cnet.com/home/security/carbon-monoxide-detector-placement-guide/ (Accessed March 2025)
[4] “How Do Smoke Detectors Work?” nist.gov/how-do-you-measure-it/around-the-home/how-do-smoke-detectors-work (Accessed March 2025)
[5] “What Kind of Smoke Alarm Should I Buy?” nfpa.org/news-blogs-and-articles/blogs/2023/03/06/what-kind-of-smoke-alarm-smoke-detector-should-i-buy (Accessed March 2025)