How To Look At A House
McGarry and Madsen's home inspection blog for buyers of
site-built, mobile/manufactured and modular homes
What is the difference between a smoke alarm and a heat alarm?
Friday, March 4, 2022
It’s simple enough: a smoke alarm detects smoke and a heat alarm detects heat. But there’s more to it than that. Smoke alarms are required in a residential setting where people sleep. Today’s code mandates one in each sleeping room, and also in the access area just outside the sleeping rooms. They recognize the presence of a fire quickly at the first sign of smoke, and awaken residents to give them time to escape the building before the fire spreads.
But the high sensitivity of smoke alarms has its drawbacks. False alarms caused by things like burnt toast or bathroom shower steam can be a problem, and they do not function well outside of conditioned living spaces. Extreme heat or cold, humidity, and dust can make them malfunction or fail. So smoke alarms are not recommended for installation in a garage, unfinished attic, or crawl space.
Heat alarms, on the other hand, perform well in the same areas that are problematic for smoke alarms. They are also definitely the right type of alarm for a garage, where plenty of house fires begin due to the gasoline and flammable chemicals that are often stored there.
The average heat alarm is triggered when the temperature exceeds 135º F or rises by 15º F or more in less than a minute. Unfortunately, an attic in Florida can easily reach above 135º F on a hot summer afternoon, so there are also heat alarms that hold off until 195º F before sounding the alarm.
Electronic heat alarms can be interconnected with the home’s smoke alarms so that they all go off if a heat alarm senses a fire, and some even offer wireless connections. But, long before today’s high-tech microprocessor sensors, there were wind-up mechanical heat/fire alarms that were activated by an internal fusible link. To read about them, go to What is that strange retro-looking smoke alarm?
• • • • • • • • • • • • • • • • • • • • • • • • • • • •
Here’s links to some of our other blog posts about “SMOKE AND CO ALARMS":
of Blog Posts
Top 5 results given instantly.
Click on magnifying glass
for all search results.
Buying a home in North/Central Florida? for a team inspection by two FL-licensed contractors and inspectors. Over 8,500 inspections completed in 20+ years. In a hurry? We will get it done for you.