Single-zone vs Multi-zone Smoke Ventilation

Smoke ventilation systems are designed to keep escape routes clear during a fire by removing smoke and heat from the building.

One of the first things to understand when looking at smoke ventilation is whether your project requires a single-zone or multi-zone system.

This will depend on building layout, the number or areas (zones) that need to be protected and how the system is expected to operate in a fire.

What is a Single-zone Smoke Ventilation System?

A single-zone system protects one are only, such as a stairwell, corridor, or lobby.  In this type of system, everything operates together.  When smoke is detected, the control panel triggers the vent to open, allowing smoke to escape.

Because it only services one space, the setup is relatively straight forward and typically includes:

• An AOV (roof hatch, skylight, or window)
• A single zone control panel
• Smoke detectors/manual call points
• Breakglass/reset/monitoring switch

There is no need to control multiple areas or prevent smoke spreading between zones, the focus is simply on clearing smoke from that one escape route.

We supply single-zone AOV kits, with everything you need for a complete, certified system.

What is a Multi-zone Smoke Ventilation System?

A multi-zone system is used when more than one area needs to be protected, and the interaction between those areas is important, requiring independent control.

Instead of everything opening at once, the system is programmed carefully to prevent the operation of one zone inadvertently letting smoke enter a different zone.

This helps remove smoke from the fire location and prevent smoke spreading into other parts of the building.

These systems are more complex and are commonly used in larger buildings with multiple floors or corridors.

A multi-zone system may include:

• Multiple AOVs across different floors or areas
• Either a central control panel or multiple smaller ones alongside a communication network
• Dampers or vents that open or close depending on where smoke is detected
• A smoke shaft
• Fans (for mechanical systems)

Because of this, multi-zone systems rely on a clear cause and effect strategy.  The system needs to know exactly what should open, what should stay closed and how air will move through the building during a fire.

This is where correct specification becomes important.  We review your drawings and fire strategy to make sure that the system is set up correctly from the start, then supply all required components as a complete system.

The Key Difference Between Single and Multi-zone Systems

The main difference comes down to how many areas are being protected and how the system responds in a fire.

A single-zone system is focused on one space, with everything operating together.  It is simpler, quicker to instal land commonly used in straightforward layouts like individual stairwells.

A multi-zone system is designed for larger or more complex buildings.  It separates different areas and controls them independently, so only the affected zone operates.  This adds complexity but is essential for preventing smoke spread and maintaining safe escape routes across the building.