What’s The Difference Between a Smoke Detector and Smoke Alarm?

The terms “smoke detector” and “smoke alarm” are often used interchangeably but there are differences that are important to understand. Both devices are designed to detect smoke, but one is designed to be part of a larger system and the other is meant to be more stand-alone.

Smoke Detectors

Smoke detectors do what their name implies, they detect smoke. They are usually part of larger security systems or fire systems that have an alarm that is separate from the smoke detectors. In other words, when a smoke detector senses smoke, it sends a signal to a central alarm system and that system does the alerting, usually through an audible alarm. It is common for these types of systems to be monitored by a third-party company, such as a home security company.

Smoke Alarms

Smoke alarms also sense smoke, but they differ from smoke detectors in that they also have an audible alarm built into each unit. Some of these devices are completely stand alone, where each unit only sounds by itself, and many of them are connected to each other either through a hardwire or wireless connection. In the case of them being connected, as an added safety measure, when one alarm sounds, they will all sound at the same time.

What is the Correct Term?

Most people have smoke alarms in their homes. In fact since the early 1990’s, interconnected smoke alarms have been required in all new homes in the United States. You  may have smoke detectors if you have a security system that includes smoke detectors. It’s very possible to have both especially in the case of a home that came with hardwired smoke alarms. When a security system gets added that has smoke detectors, the original smoke alarms are usually left in place, effectively giving you both smoke alarms and smoke detectors.

It's okay to use either term most of the time. Any fire safety professional will understand what you mean, or will ask clarifying questions if needed. If you are purchasing new devices, it is probably better to use the correct terms so that you get the right device. Just remember, you probably mean "smoke alarm" unless it's connected to another system, like a security system.

Last Updated: 11/30/2023