Difference Between Heat Detector and Smoke Detector
By Rebecca Rodriguez - January 15, 2023

Both smoke detectors and heat detectors are used to identify potential fires. When coupled with an alarm system, one of these sensors will transmit an alert to the panel when engaged. This will result in a system alert event, triggering all sounders and sirens to inform everyone. However, many people confuse these gadgets, which is incorrect. There are several distinctions between a heat detector and a smoke detector, as well as variances in their fundamental purposes.

Summary Chart
  1. The detector is triggered by smoke
The detector is triggered 
Smoke, fire detector.

Getty images/ Moment/Roman Studio


Smoke detectors are classified into two types. These are photoelectric and ionization smoke detectors. A photoelectric smoke detector operates by utilizing a tiny internal light. When smoke enters the chamber, the light refracts, and the interruption of the interior light signals the sensor to activate and warn the system.

An ionization smoke detector contains two internal electrically charged plates with a small quantity of radioactive material between them. When smoke enters the chamber, it disrupts the current flow and activates the sensor. Photoelectric smoke detectors are often more dependable than ionization smoke detectors, but both perform well.

Heat detectors are also classified into two types. Fixed heat detectors and rate-of-rise heat detectors are also available. Fixed heat detectors respond when they detect an exceptionally high temperature, which can only be found in a fire. Meanwhile, rate-of-rise heat detectors respond when the temperature rises at an extremely rapid rate, such as 10 degrees Fahrenheit in one minute. Some heat sensors serve both functions.

Smoke Detectors vs. Heat Detectors

The way smoke detectors and heat detectors work is what distinguishes them. Heat detectors activate when they detect high temperatures or temperatures rising at a high-speed rate, whereas smoke detectors trigger when they detect smoke. A smoke detector will usually notice a fire faster than a heat detector. However, there are some cases when heat detectors are preferable. However, in most cases, a smoke detector will suffice. There are also smoke and heat detectors that do both purposes.
Another distinction between the two detectors is their operating principles. Heat detectors use electro-pneumatic technology and thermocouples, whereas smoke detectors use ionization and photoelectric technologies.

Heat detectors are more dependable and do not produce false alerts as smoke detectors, and they only raise an alert when the temperature rises to unsafe levels. Another thing to remember is that heat detectors do not sound a signal in the presence of smoke, and smoke detectors do not sound an alarm even if the temperature rises because they are not meant to replace each other.