Heat detectors warn of fire when the temperature in the area around the smoke detector reaches a certain level. Heat detectors do not notice smoke. Some studies show that heat detectors may not provide early enough warning to aid escape from a life-threatening fire. However, a heat detector could be valuable additional protection in areas such as kitchens and attics, where smoke detectors are not recommended. They are not recommended for the use in bedrooms or sleeping areas. There are several types of heat detectors including:
- Rate-of-rise heat detectors: If the temperature sensed by this type of detector increases faster than a specified rate, an alarm will be initiated. A typical rate may be 8.3 degrees Centigrade per minute. In most of these detectors, when the rate of rise element alone has been activated, the detector is self-restoring.
- Fixed-temperature heat detectors: If the temperature at the detector rises to the detector’s rated temperature, an alarm is initiated. Often, when actuated by the fixed temperature element, the detector is non-restorable and must be replaced. A typical set temperature might be 57.2 degrees Centigrade.
- Combined rate-of-rise/fixed-temperature heat detectors: Some heat detectors combine both features, providing warning when the rate-of-rise and/or the absolute temperature is exceeded.