Fire Protection Systems

 Fire Protection Systems

Within our reading this week, we learned of various systems that can be installed to help alert and protect a building’s occupants from a fire. While fire and smoke are the main threats to the occupants safety, there are other potential hazards when a fire is present, such as changes in temperature (heat) and gases. Due to the fact that any sort of fire poses a large risk, aside from just burning, it is very important to detect and control such a danger as soon as possible. There are certain systems designers and engineers use to communicate these dangers known as detection systems, alarm systems, and extinguishing systems.

Detection Systems

It should be well known that one of the best ways to protect occupants from the dangers of a fire is to simply know there is a fire as quickly as possible. Detection systems, or initiating devices, are required by the IBC and IFC in all new buildings unless exempt. However, choosing the appropriate detection system is based on a few factors such as the exiting needs and risk factors of the occupants, whether or not the building type houses sleeping accommodations, and any characteristics of a fire that may occur.

Although different types of fires have different signatures, the most typical sign of any fire is smoke. This is especially seen in liquid fires where the actual fire causes a drop in temperature, as opposed to a rise, therefore, smoke detectors are best for smoldering fires and heat detectors are best for flaming fires in larger spaces. The codes specify which type and use of detector is required for a certain building. The building codes, fire codes, and the LSC all indicate when a detection system is required by referencing the NFPA 72. This provides the minimum performance location, installation, and maintenance for each system.

Alarm Systems

Alarm systems are typically used for other emergencies, including fires, in order to make occupants aware that something unusual is happening. These systems can be used to warn occupants and evacuate them or to notify them of other emergencies like toxic spills, extreme weather, or threats. The LSC, fire codes, and fire protection chapters found in the building codes all specify the location, type of alarm, and wiring required for each alarm within the system. They do this by referencing the NFPA 72 as well, and use the ICC A117.1 and the ADA standards for accessibility requirements in regard to these systems.

Smoke alarms are a type of smoke detector that detects smoke and typically sets off an alarm. These alarms can be either single-station or multiple-station alarms. In the case of a single-station alarm, the alarm only sounds at the device that detects the fire, alerting the occupants within that area. On the other end, multiple-station alarm systems are a set of devices that are interconnected so that when one device goes off, the rest will too.

Fire alarms, on the other hand, are a notification appliance that is also part of a fire alarm system and is initiated by a detector. The signal is dependent upon the use and type of occupants within the building or specific zone in the building. Both the NFPA 72 and LSC require low-frequency fire alarm notification signals in structures that cater to people’s sleep such as hotels and dormitories. Any and all alarm systems are tied to the electrical system ofa building and can be tied to other similar systems.

Extinguishing Systems

An extinguishing system provides the control and extinguishment of fires once they have occurred, also known as suppression systems. Typically, a mechanical engineer needs to be involved in the selection and installation of the alarms. Some are intended to be used by occupants while others are not, so it is important to understand the most common ones, like fire extinguishers, standpipes, fire hoses, and sprinkler systems.

Portable fire extinguishers are meant for use by the occupants of a building and do not require access to plumbing lines, therefore, they are movable. This type of system can be surface mounted or recessed within a wall. However, cabinets must either have a vision panel or are clearly marked because the extinguisher has to always be visual. The fire codes and the LSC are the codes responsible fore specifying the occupancies and types of building uses requiring fire extinguishers. Codes also refer to NFPA 10, Standard for Portable Fire Extinguishers, to provide additional detailed information.

Standpipes and fires hoses are usually installed during the initial construction of a building. These types of systems are a manual, fixed fire system that the IBC, IFC, or NFPA determine which is most needed based on the height, number of stories, and the building is sprinklered or un-sprinklered. For standpipes, the codes establish three classes that are dependent on the purpose and intended use of the system. The first of the three is Class I that consists of pipes with high-pressure outlets for hookup to a fire department hose. These are usually seen in buildings without sprinklers or high-rise buildings. The second is Class II that have hoses attached and are designed for small-scale fire protection, therefore they are mostly used in buildings with no sprinkler system. This class of standpipes can be used by occupants who have been properly trained. Class III, the last class for standpipe extinguishing systems, is a combination between the previous two classes. It is designed for use by trained building occupants or the fire department, so it also includes an outlet for fire department hookup.

Conclusion

Based on the information above, designers are equipped to select the best fire protection system for their project. This is done through the use of the building codes, the fire codes, the LSC, and the NFPA 72 or NFPA 10. Referencing these codes, or any codes associated with the projects jurisdiction, is crucial for the occupants safety.