A home inspection may or may not tell you what type of smoke alarm is installed, just that there is one (or several). It’s good to know the differences, and the benefits of each.
There are two types of smoke alarms: ionization alarms, and photoelectric alarms.
Installed in 90% of all homes in the USA, ionization alarms respond very quickly to “fast flame” fires caused by accelerants like grease, gasoline, or paper. However, when it comes to “slow flame” smoldering fires (before open flames develop), ionization alarms respond 15-50 MINUTES slower than photoelectric alarms and can actually fail to activate 20-25% of the time.
Photoelectric alarms are installed in 5% of all homes in the USA; yet they provide far superior smoke alerts since they are less prone to nuisance tripping; they address the full spectrum of fires (fast- and slow-flame); and they provide adequate escape time 96% of the time, compared to 80% for ionization alarms. This gives the photoelectric smoke alarm the clear advantage!
To be safe, since smoke alarms should be replaced every 10 years anyway, consider replacing an ionization alarm with a photoelectric or combination alarm to get the best of both worlds.
The last thing to consider is whether you should use a hard-wired alarm system or battery-operated. The best choice is to use a hard-wired alarm, just in case you forget to change the batteries… but make sure it’s a hard-wired alarm with battery backup, in case the power goes out.
Where to install smoke alarms:
- Every level of the home
- Garages and Basements
- Install a smoke alarm in the center of a ceiling, or high on a wall.
- Don’t install smoke alarms near bathrooms (humidity can set them off); near ceiling fans or windows (which can dissipate smoke and result in a too-late alarm); or near a heat source.
- It’s recommended to use both ionization and photoelectric smoke alarms (or combination alarms) on every level of a home, except do not use ionization alarms in or near the kitchen because they’re likely to cause nuisance alarms during cooking.
- Install hard-wired alarms with battery backup, wherever practical
- Test your smoke alarms every month (the day you pay your mortgage)
What about carbon monoxide detectors? These are a must if you have a fireplace, wood stove or pellet stove; gas oven and cooktop; gas water heater; gas furnace; and gas clothes dryer.
If the home is all electric, consider a carbon monoxide detector if you have an attached garage. Carbon monoxide, or CO, isn’t just associated with natural gas. It can enter the home through:
- Leaving the car running in an attached garage
- A space heater in an attached garage or chilly basement
- A portable generator being used in an attached garage or shop
These tips will help keep you, your family and pets safe in the event of fire or a gas leak. And remember – have a clear escape plan ready, as well as a safe meeting place in case you can’t communicate with one another!