The fire alarm system in Macalister consists of a series of manual pull stations located at all major exits, smoke detectors, heat detectors,  fire alarm bells in core spaces, and an annunciator panel.

Manual Pull Stations:

A manual pull station is used to alert the occupants of a building in the event of a fire. Pull stations are usually placed near an exit, so as people are exiting during a fire event, they can enact the pull station and warn the rest of the building. The pull station is tied in directly with the fire alarm system, and will sound the local alarm. Most likely, the signal from a pull station will also be sent to the central security office at Drexel. A typical manual pull station is pictured below:

Smoke and heat detectors send a signal to the alarm system upon the detection of smoke or heat in a space. The smoke detectors in Macalister are most likely of a photoelectric type that sense the particles that result from combustion and smoke. Smoke detectors are usually installed in areas where miscellaneous smoke is not a problem. For instance, smoke detectors are rarely installed in kitchens because of the high incidence of false alarms. Heat detectors detect an increase in heat in a space, and then send a signal to the fire alarm system.

Smoke and heat detectors should be installed at 30' spacing in large rooms, but larger allowances are made for long and narrow hallways. Detectors can be installed on the ceiling or on the side wall, however, they should never be installed within 8" from the intersection of a side wall and ceiling. This area is called the "dead area", since smoke and heat rarely finds its way into the exact corner of a space.

Below is a picture of a heat detector located in Macalister Hall:

Fire Alarm Bell:

The fire alarm bell is the primary notification device in Macalister Hall. Upon a signal from a pull station or detector, the fire alarm bell will sound to warn occupants of a fire hazard and begin an evacuation of the building. Fire alarm bells are usually installed in central areas so that the sound can be heard equally in all directions. Additionally, bells are usually installed near the ceiling to be kept out of the way of traffic. A fire alarm bell in Macalister Hall is pictured below:

Annunciator Panel:

Annunciator panels are the core of the fire alarm system. All of the components to the system are tied into the annunciator panel. This panel will tell where an alarm was first set or where exactly a pull station was activated within the building. Most fire codes require that the annunciator panel be placed in close proximity to the major entrance. This placement is crucial because when the fire department arrives, they can look at the annunciator panel and figure out exactly where the fire is very quickly.