Fire Sprinkler Systems | Fire Prevention & Safety Guide

Fire Sprinkler Systems: A Beginner's Guide

A fire sprinkler system is a simple yet critical component of a building or residential fire protection system.

Installed on ceilings or side walls, the system consists of a water supply, a water distribution piping system, and sprinkler heads. The sprinkler automatically discharges water when a fire is detected but is not triggered by smoke. It controls or extinguishes the fire, serving as both a fire detection and suppression system.

Fire sprinkler systems have been in use since the late 19th century and are now widely applied worldwide. More than 40 million sprinkler heads are installed each year. These systems typically operate by holding water under pressure in a network of pipes running through a building.

Types of Fire Sprinkler Systems

There are four main types of fire sprinkler systems:

• Wet Pipe

• Dry Pipe

• Deluge

• Pre-Action

Wet pipe sprinkler systems are the most common type used in residential buildings. Cold water is stored under pressure in the pipes and is immediately released when the predetermined temperature is reached.

Dry pipe sprinkler systems are used in unheated or unoccupied buildings where pipes may freeze and burst. Pressurized air or nitrogen gas is stored in the pipes, connected to a water supply. When a fire is detected, the air is released, allowing water to flow through the pipes to the sprinkler heads.

Deluge sprinkler systems are used in areas where fire spread is a major concern, such as storage facilities or loading docks. The nozzles remain open at all times, and an alarm system triggers a water release valve when a fire is detected.

Pre-action sprinkler systems combine features of wet and dry pipe systems. Water is not stored in the pipes until a fire is detected, at which point it is released to the sprinkler heads. The response time is as fast as that of a wet pipe sprinkler system. These are often used in areas where water damage must be minimized.

Additionally, SMART (Simultaneous Monitoring, Assessment, and Response Technology) sprinklers, which use multiple detection technologies for faster response, are being developed.

Sprinklers that discharge water mist instead of traditional water spray are another alternative.

Fire Sprinkler Heads

A fire sprinkler head is the component of the system that discharges water when a fire is detected. It comes in various designs.

Each sprinkler head contains a triggering mechanism that releases water onto the fire.

• Conventional heads are suitable for most residential fire sprinkler systems and direct some water toward the ceiling.

• Upright or pendant sprinklers aim water straight down, making them ideal for high-ceiling rooms.

• Sidewall sprinklers are mounted on a high point of the wall and offer broader water coverage than conventional heads.

• Aesthetic considerations can be addressed with recessed sprinklers or cover caps to make them less obtrusive.

The plug inside the head that holds back the water is typically made of Wood's metal, a low-melting alloy, or a glycerin-based liquid-filled glass bulb that expands and shatters upon heating, releasing water.

Each sprinkler head activates independently, ensuring only the sprinklers above the fire operate. This maximizes water pressure over the fire while reducing unnecessary water damage to the building.

Fire Sprinkler System Installation and Costs

Fire sprinkler systems should only be installed by companies certified by recognized organizations. Factors such as existing pipework, electrical systems, and water pressure must be considered, especially in retrofitting projects.

Residential systems typically cost around $30–$40 per square meter, while commercial or industrial installations range from $33–$35 per square meter.

Maintenance requirements are minimal, typically requiring two professional inspections per year in addition to regular visual checks.

Fire sprinkler systems provide long-term safety and financial benefits, preventing both fire and water damage. In buildings equipped with sprinkler systems, 99% of fires are controlled or extinguished. The losses from fires in buildings with sprinklers are estimated to be only a tenth of those in unprotected structures.

In the long run, investing in a sprinkler system is a life-saving and cost-effective decision.