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Fire Protection and Security

Detection

Fire detectors commonly found in cultural institutions are manual fire alarm pulls (which provide a quick way to activate the alarm system during occupied hours), heat detectors, and smoke detectors. Often a combination of different types of detectors will be used, depending on the building construction and other needs. Detection systems often play a part in activating the fire suppression system.

Heat Detectors

Fixed-temperature heat detectors are designed to operate when the room reaches a predetermined temperature (usually a fairly high one). These do not detect smoldering fires well. Rate-of-rise heat sensors are better, since they are activated by a sudden, small increase in temperature, but in general heat sensors do not work until the temperatures in the room are quite high and the fire is likely to be well developed.

Smoke Detectors

Smoke detectors can detect a fire before it gets out of control.

Smoke detectors are designed to detect a fire while it is still in its incipient stages. There are several types (photoelectric and ionization) that work on different principles. Smoke detectors are usually spot units that are placed along ceilings or high on walls. A third type of detector, the air aspirating system, is very sensitive to smoke and might be considered for areas in which extremely valuable collections are stored. These units draw an air sample in, analyze it, and than return it to the space. If smoke is detected, the alarm system is activated.

System Controls

The control panel of a detection system monitors the various detectors within the system, as well as the devices that announce or respond to the alarm (bells, lights, building HVAC controls). There are two basic types: conventional and addressable. Conventional systems usually have several zones, each of which may have a number of smoke detectors and manual pull stations. An alarm in one zone cannot indicate which specific detector was activated, so depending on the size of the zones, fire personnel may have to search for the fire. Addressable systems are more complicated and expensive, and they require more training of building maintenance personnel. However, they can indicate which specific alarm has been activated and detect any faults in the system circuits.

For more information on fire detection and suppression systems, see An Introduction to Fire Detection, Alarm, and Automatic Fire Sprinklers. Always contact an appropriate fire professional to determine the best type of fire protection system for your building.