Building owners and facilities managers should be taking practical steps now to prepare their buildings for a potentially heavy bushfire season. Reviewing existing air filtration and HVAC controls, as well as establishing clear procedures for responding to deteriorating outdoor air quality, can help reduce smoke entering buildings and protect the people using them.
With improved filtration technology and the introduction of new Australian filter standards, there are opportunities to strengthen building resilience without significant investment. The starting point is understanding your HVAC system’s capabilities and identifying where targeted improvements can make the greatest difference.
Make better use of existing filtration
Most buildings have opportunities to improve filtration, even those with limited space for additional filters or little spare fan capacity.
Australia’s transition from AS 1324 to AS 16890 introduces a new approach to classifying air filters based on their efficiency in capturing airborne particles of different sizes. With filters rated to the new standard now readily available, building owners have an opportunity to review whether their existing filtration is providing adequate protection against fine particles, including those found in bushfire smoke.
Importantly, improving filtration doesn’t necessarily mean increasing the load on existing HVAC systems. Depending on the filters selected, AS 16890-rated alternatives may have a similar or even lower pressure drop than existing filters, allowing improved particle capture without significantly affecting airflow or cooling performance.
However, it’s still important to understand their operational impact. Higher-efficiency filters may affect energy consumption and replacement intervals.
Action:
- Review existing air-handling units, fan capacity and filtration arrangements
- Identify suitable filter upgrades and assess their impact on airflow, cooling performance, energy consumption and maintenance requirements
- Consider upgrading existing filters to improve everyday indoor air quality while strengthening preparedness for bushfire smoke events.
Set up a bushfire operating mode
Building management systems (BMS) can be programmed to include a dedicated bushfire mode which allows operators to easily disable economy cycles, night purging or other similar modes of operation which introduce additional outside air to improve energy efficiency.
During a smoke event, limiting this additional outdoor air can help reduce smoke entering the building and particulate load on your filters, while maintaining required code-compliant ventilation levels.
We recommend making these minor adjustments before smoke arrives so it can be tested in advance. This is less risky than relying on a controls’ contractor to make adjustments when smoke arrives which will take longer to action, be reliant on contractor availability and involve manual overrides. These overrides will need to be undone by the contractor after the smoke event has passed and spurious alarms are likely to be generated due to the unplanned nature of the intervention.
If your building has its own weather station, or access to a nearby source of air quality information, the initiation of bush fire mode could be automated with notifications sent to your facility management team.
Action:
- Review your BMS to see whether a bushfire mode is available or enabled
- Seek advice about how best to modify existing controls sequences to limit outside air ventilation whilst still complying with building codes
- Educate your facilities team on enabling this mode.
Test your systems and prepare your people
Facilities teams should test their building’s bushfire operating mode annually, ahead of the bushfire season, and following significant changes to HVAC equipment or controls. Testing should confirm that the intended control sequences, such as economy cycles and night purging, are disabled as intended while maintaining acceptable ventilation rates and indoor conditions. It should also verify that the system returns correctly to normal operation.
Testing provides an opportunity to familiarise building operators with the controls, establish clear activation procedures and understand how the changes may affect building performance. This preparation can help facilities teams respond promptly and confidently when outdoor air quality deteriorates.
An audit of any standby filters for sensitive areas should also be conducted annually so that facilities managers have confidence that the required filters are available if needed.
Action:
- Test the bushfire mode operation to ensure that relevant consequences are disabled and that adequate indoor air quality is sustained
- Test that systems return to normal following return to normal operation
- Complete an annual audit of standby filters to make sure this aligns with current operational needs.
Start with what you’ve got
For building owners and facilities managers, the first step could be as simple as engaging a specialist to carry out a bushfire smoke audit to review existing HVAC documentation, commissioning records and control strategies. This can help you identify whether you have a sufficient strategy in place or whether your building would benefit from some practical improvements.
Preparing commercial offices for bushfire smoke is about understanding what your existing systems can do and being ready to use them effectively when conditions deteriorate.
Action:
- Get in touch with an HVAC specialist, like NDY, to enquire about auditing your HVAC systems and controls. In the first instance, it may be a simple case of adjusting your controls or upgrading your existing filters.
- Act now, before what’s anticipated to be a scorching summer sets us alight.
