Choosing the right fire sprinkler system

Making sure you get the right sprinkler system for your commercial or industrial property is part of the comprehensive service we provide at Fire Control Services. The sprinklers you see attached to the ceiling are just one part of a complex system that includes sensors, water supply pipes and control systems.

Did you Know? Sprinkler heads are activated by heat — they are not activated by smoke.

The Benefits of an Automatic Fire Sprinkler System

The goal of an effective automatic fire sprinkler system is to protect against loss of life and minimise property damage. In NZ, fire sprinkler systems have a 99.5% success rate in controlling a fire and allowing time for people to evacuate. 

One of the significant benefits of an installed sprinkler system is that, in the event of a fire, water damage is much reduced compared to other methods, such as water hoses. This is because modern sprinkler systems only activate where they are required and often detect fire incidents in their very early stages.

A properly integrated sprinkler system will also trigger evacuation alarms to help protect the occupants of the building.

Evaluation

The sprinkler installation process begins with an evaluation of the site and its features such as:

• Ceiling height

• Construction style

• How many people use the space

• Any existing hazards, e.g. flammable materials,

• Available water supply

To be compliant and effective, an automatic fire sprinkler system needs to be fit for purpose and designed specifically for the location and activity taking place. For example, a manufacturing site with hazardous chemicals will have more stringent requirements than a company office.

Sprinkler System Design

Did you know? Sprinkler systems are usually connected to the town’s main water supply by a much larger pipe than the one connected for drinking. This is a separate unmetered water supply.

A demand calculation determines the size of the incoming water pipe that a building requires to stop a fire.

Unlike what you see in the movies, the activation does not set off all the sprinklers at once. If all the heads were activated, the water supply would be insufficient to allow each head to work as designed. The sprinkler heads only activate as required until the Fire Brigade arrives and their fire engine can boost the supply and pressure of the water so that more sprinkler heads can operate correctly. Engineers design these systems, and we can do this design work for you.

Some Sprinklers require additional pressure to supply the necessary amount of water to operate the system as designed. The building may need a diesel or electric pump fitted in these situations. 

Sprinkler Classifications

An update to the NZ Standard NZS 4541 for commercial and industrial sprinkler systems was released in 2020, adding changes to incorporate better earthquake resilience and improving systems for tall and large buildings. NZS 4515 is the standard for residential buildings, rest homes etc. For domestic fire sprinkler systems, NZS 4517 is the standard.

Types of Fire Sprinkler Systems

There are four distinct sprinkler system types used in New Zealand:

• Wet Pipe

• Dry Pipe

• Deluge

• Pre-Action

Wet pipe systems are the most common, and as the name suggests, the pipes in the system are always filled with water under pressure, ready to release in the event of a fire. 

Did you know? Each sprinkler in a wet pipe system has a glass bulb that contains heat-sensitive fluid. When the heat in the room builds up, this fluid expands and eventually bursts, allowing the water to flow from the sprinkler.

Dry pipe systems are less common in NZ and are typically installed in situations where standard water-filled pipes could freeze and become inoperable. Applications include refrigerated spaces or unheated buildings. In a dry pipe system, the pipes are filled with pressurised air, which quickly releases when activated, triggering a water valve to open.

Foam/Water Deluge systems feature open sprinklers (no glass bulb) and are employed in higher-risk environments where a fire might spread rapidly. These systems allow for high volumes of water to be sprayed across the whole zone simultaneously. Deluge systems are often a feature of underground infrastructure, such as Auckland’s Waterview tunnel.

Pre-Action systems are used in sensitive locations such as museums or data centres, where accidental activation is highly undesirable. They have a more complex detection system that offers more protection and often use alternative fire suppression methods.

Maintenance & Testing

Regular testing of fire sprinkler systems is essential to building compliance. Most systems require a monthly test to ensure they are functioning and compliant (Deluge systems only require an annual test). 

Fortunately, with a Fire Control Services contract, you don’t have to worry about compliance and testing schedules—we look after all of that for you. For total peace of mind, our Building WOF service offers complete management of your building compliance and IQP reporting obligations.

As a building owner, there are some checks you can do yourself to ensure your system is safe, including:

• Checking that materials are stacked correctly and not too close to sprinklers

• Making sure evacuation sirens are not blocked

• Protect sprinklers from impact damage

•  Store combustible items, e.g. waste cardboard, outside of the building

• Train your staff in how to use extinguishers

• Conduct regular fire drills

Did you know? We offer staff training on fire safety and the proper use of equipment such as extinguishers and fire hoses. 

At Fire Control Services, fire safety testing and compliance are part of our core services. 

We ensure your property’s fire safety systems are performing as they should. We can also quickly resolve any maintenance issues or recommend upgrades. 

Diesel Pump Systems

If your sprinkler system has a diesel pump, we provide additional testing and service requirements to ensure it is functional and compliant.

• We operate the diesel pump for 30 minutes to ensure its working (weekly)

• Annual service of the diesel engine

• Annual inspection survey (two-yearly for some systems)

• Replacement of starter batteries (every four years)

If you’re looking to renovate or planning an addition to your property – get in touch, and we can audit your site and provide a full quote for upgrading your fire safety systems.