When hearing about fire protection, we tend to think about automatic sprinklers and fire alarms. However, these are just two among many components that protect building occupants from fire. Smoke is also dangerous, capable of causing death by poisoning, so it must be controlled as well. In addition, buildings must include measures to help firefighters work more effectively when fire cannot be controlled by sprinklers alone.
This article describes the main components of fire protection systems, while indicating the NYC Building Code sections with the corresponding technical requirements. Keep in mind this is just an informative guide, not to be used in the place of building codes for an actual project.
Automatic Fire Sprinklers
Code Section: BC903
As implied by their name, automatic sprinklers respond to fire with no need for human intervention. Movies and TV series have spread some erroneous ideas about fire sprinklers; for example, there is a common belief that sprinklers shower indoor spaces completely with the slightest sign of smoke. In reality, fire sprinklers operate automatically as they respond to heat, and in many cases one sprinkler is enough to douse a fire.
An automatic sprinkler system for a large building can represent a sizable investment, but repairing the damage of an uncontrolled fire can be much more expensive. In addition, occupants may suffer disabling injuries or even lose their lives.
The recent Trump Tower fire in NYC could have been mitigated or prevented altogether with automatic sprinklers. However, they are only required in new residential towers or existing ones that undergo a major renovation. In the case of office buildings at least 100 feet tall, Local Law 26 of 2004 mandates fire sprinkler installation by July 1, 2019, but there is no equivalent document for residential towers.
There are special applications where discharging water is hazardous, and other fire-extinguishing substances are used instead (BC 904). Some examples are foam, carbon dioxide and halon.
Code Section: BC905
A standpipe is a piping system that delivers water from a main source to hose connections in key locations throughout a building. These connections are used by firefighters, and the NYC Building Code covers five possible standpipe configurations:
Dry standpipes are normally filled with pressurized air, and water enters the system when needed; on the other hand, wet standpipes are permanently filled with water. Automatic systems establish the required flow by themselves, while manual systems rely on an FDNY pumper truck. Semi-automatic systems need a remote signal to activate, but can establish the required flow by themselves once this happens.
Standpipes can also be divided into three classes, based on their hose connections:
2-1/2" hose connections for the FDNY and for occupants who have been trained in handling heavy fire streams.
1-1/2" hose connections for occupants, of for initial response by the FDNY.
Both connection types. The 1-1/2" connections are for occupants, while the larger 2-1/2" connections are for the FDNY and for occupants trained in handling heavy fire streams.
Fire Alarm Systems
Code Section: BC907
A fire alarm system monitors the building for the presence of fire, producing audible and visual signals if fire is detected. A control unit receives inputs from all fire detection devices, automatic or manual, and activates the corresponding notification systems. In addition, fire alarms can be used to initiate the adequate response measures when fire is detected.
It is important to note that fire alarm requirements change significantly depending on the occupancy classification of the building in question. Following the right set of requirements is the first step for a code-compliant fire alarm design.
Fire alarms must not be confused with emergency alarms (BC 908), which are used to signal dangerous conditions that involve hazardous materials.
Smoke Control Systems
Code Section: BC909
Humans avoid fire by instinct, but the hazards associated with smoke are not common knowledge. In addition to limiting visibility, smoke can cause poisoning if large enough amounts are inhaled. Therefore, a fire protection system must also be capable of handling smoke effectively, avoiding its accumulation and removing it from the building. Note that smoke movement is driven by pressure and temperature: you will not see smoke flowing from a lower-pressure area to a higher-pressure area, and it also tends to rise along with hot air.
Mechanical systems use fans to control smoke movement.
Passive systems use smoke barriers to limit is movement, which don’t consume power.
One of the most important requirements for a smoke control system is keeping elevator shafts and staircases clear. These areas are used to evacuate the building, and smoke accumulation can make escaping more difficult for occupants.
Smoke and heat vents are covered in a dedicated code section (BC 910).
Fire Command Center
Code Section: BC911
A fire command center is required in various occupancy classifications, including high-rise constructions. The fire command center is a centralized location that displays the status of various fire protection systems, such as detection equipment, alarms, communication systems and controls. It also provides manual control for many of these systems.
The fire command center must be accessible. The NYC Building Code requires it to be installed in the lobby of buildings, on the main entrance floor, and near the FDNY designated response point. The main components required are:
Fire alarm controls
Auxiliary Radio Communication System (ARCS) control panel
Smoke control system panel
Post-fire smoke purge system control panel
FDNY telephone system
Public address system
Manual release for automatically-closing doors
Fire Department Connections
Code Section: BC912
As implied by their name, fire department connections are used by the FDNY for hoses and pumping equipment. They must be located where they don’t obstruct firefighting operations, while providing optimal coverage - the code requires at least one connection for every 300 feet of exterior wall length (note that exceptions and special cases apply).
Code Section: BC913
As you might guess from their name, fire pumps are used to establish a reliable water supply for all fire protection systems that require it. If a fire pump is used with the sole purpose of supplying water for a fire sprinkler system, it is considered a sprinkler booster pump.
Note that fire pumps are normally powered by electricity. NYC codes provide a list of requirements for the backup power systems for fire pumps, ensuring their operation even if the electric service is interrupted during an emergency.
Fire pumps are expensive, but they are not mandatory for all fire protection systems. With smart design decisions, it may be possible to avoid their use completely while still having a code-compliant system.
Post-Fire Smoke Purge
Code Section: BC916
As previously stated, smoke hinders visibility and is extremely dangerous when inhaled. Clearing the smoke in a building is important to resume building operation as soon as possible once a fire is extinguished. This is precisely what post-fire smoke purge systems do: eliminating smoke quickly after a fire incident.
Since post-fire smoke purge systems operate after a fire, they are not classified as life safety systems. Nevertheless, their use is mandatory in all occupancy groups indicated by the code.
Auxiliary Radio Communication System (ARCS)
Code Section: BC917
An ARCS is a communication system used by firefighters, which meets the following conditions:
Exclusive radio frequencies for the FDNY, to prevent interference
Independent from the electrical and communication systems in the building
An ARCS is mandatory in all new commercial constructions exceeding 75 feet, and new residential constructions exceeding 125 feet. It must provide optimal building coverage, providing a reliable communication system for firefighters anywhere inside the building.
Fire protection requirements in NYC are very demanding, and the associated equipment is expensive. However, you can optimize cost while ensuring code compliance by working with qualified design professionals from the design phase. Lower costs do not necessarily mean reduced fire protection.
At Nearby EngineersNew York Engineers , we search for simple, eloquent solutions to complex problems. We minimize construction costs by eliminating the extraneous and focusing on the overall efficiency for the most streamlined designs.