Bushfire Prevention Strategies using Bushfire-Rated Fans For Extra Protection

How do bushfire-rated fans help protect buildings for bushfire prevention?

Bushfire-rated fans help protect buildings against ember attacks. An ember attack occurs when the wind moves, burning bits of bark, twig, or leaf from the primary fire towards other structures.

These airborne embers can enter buildings via roof ventilation fans, gables, or other roof vents. Depending on the conditions, embers can travel as far as 50km.

How are bushfire-rated fans different in helping bushfire prevention?

Pacific Ventilation bushfire-rated fans use non-combustible materials and 1.8mm or smaller corrosion-resistant steel or bronze mesh. Non-combustible materials keep the fan housing from catching fire or melting when embers land on it, and small mesh keeps the embers from entering the building through the ducting or other spaces. These material choices make bushfire-rated fans incredibly robust.

According to the Australian Building Standard AS3959-2009, “Roof ventilation openings shall be fitted with ember guards made of non-combustible material or a mesh or perforated sheet with a maximum aperture of 2mm made of corrosion-resistant steel or bronze.”

How do I know if I am required to use a bushfire-rated fan?

The Bushfire Attack Level, known as a BAL rating, is a scale that helps define the fire risk to a building and the construction standard that must be legally met to mitigate the fire risk. A structure or area’s BAL rating is determined by multiple factors; location, vegetation, distance to the vegetation, and slope of the land under the vegetation. The BAL scale goes from BAL-12.5 to BAL-FZ.

Pacific Ventilation builds all our bushfire-rated fans to BAL-40 standards; we do not build fans to any lower BAL rating. Even if your building is in a BAL-12.5 zone, the bushfire-rated fan you buy from us will meet the specification for a BAL-40 location. Why? Because rather than building to the minimum standard, we build to the maximum standard possible.

The only BAL zone we do not supply fans for is BAL-FZ. If you have a building in a BAL-FZ zone, we can’t offer any fan products because the fan would have to withstand direct exposure to flames and heat flux greater than 40kW/m2.

Does a bushfire-rated fan work differently?

As long fans are maintained as recommended, bushfire-rated fans do not have additional pressure drops or performance losses to compensate for. Additionally, bushfire-rated fans are as quiet as non-bushfire fans. We have extensively tested the quality and behaviour of our bushfire-rated fans in our factory.

However, when making a bushfire-rated fan selection using our HVAC fan selection software, we suggest allowing an extra 10% for some debris buildup (leaves etc.) between servicing.

Can I use bushfire-rated fans even if my building isn’t in a BAL-rated area?

Any Australian business, homeowner, or builder can use bushfire-rated fans. For many, the value of increased safety and peace of mind is enough incentive to use bushfire-rated fans regardless of their BAL zone rating. Given the distance embers can travel, almost any building can benefit from including bushfire-rated fans. Remember that bushfire-rated fans are only one part of a bushfire-resilience strategy. Many other components are involved in creating a bushfire risk mitigation plan.

How do I find out more about bushfire-rated fans?

Please contact your Pacific Ventilation Account Manager or our Customer Service Team for specific information about bushfire-rated fans. For non-fan-related information about bushfire-related construction, a great place to start is with your local fire authority.