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How do I Choose the Best Fire Alarm Design?

Patrick Roland
Patrick Roland

The proper detection of smoke or a fire can save a home or business from total destruction. There are three types of fire alarm design from which you can choose. Thermal, photoelectric and ionization detectors all perform the job of alerting you to a fire, but they are useful in different situations. Based on your circumstances, you can choose the best type of system to help protect your property.

A thermal fire alarm design is the least likely type of fire alarm to go off accidentally or falsely report some conditions as fires. This type of fire alarm system normally is installed high along a wall or directly on a ceiling. It sounds an alarm only when heat levels rise to a certain level, so there is a safety concern associated with this model. The worry is that if flames must be at a certain intensity before the alarm sounds, the property will have to suffer a great deal of damage first. This model is a popular type of commercial fire alarm for businesses such as restaurants and factories that frequently have smoke in the workplace and do not want false alarms.

Smoke alarms can be part of an addressable fire alarm system.
Smoke alarms can be part of an addressable fire alarm system.

An ionization fire alarm design has a quicker response time than a thermal alarm. This commonly is used as a home fire alarm because it is small and, because it is battery powered, is not dependent upon an electrical system. The alarm detects fires because of a small non-harmful radioactive element that converts air within the alarm into an electrical current. When smoke enters this air stream, it prohibits the electrical current, and the warning sounds. These alarms are popular because they respond to smoke very quickly and provide an early warning for trouble, but they are not practical for smoky environments such as bars and restaurants.

Some factory fire alarms are designed to go off only when heat rises to a certain level.
Some factory fire alarms are designed to go off only when heat rises to a certain level.

The third kind of fire alarm design is the photoelectric detector. This also is a popular model for non-smoky businesses, such as offices and warehouses, because it can utilize the building's power supply to operate, eliminating the need to change batteries frequently. This fire alarm design operates by emitting a light beam inside a chamber. When smoke enters the chamber, it disrupts the beam and sounds the alarm. It is excellent at detecting smoldering fires but is frequently criticized for its sluggish response time to direct flames.

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    • Smoke alarms can be part of an addressable fire alarm system.
      By: Serenethos
      Smoke alarms can be part of an addressable fire alarm system.
    • Some factory fire alarms are designed to go off only when heat rises to a certain level.
      By: .shock
      Some factory fire alarms are designed to go off only when heat rises to a certain level.