California’s recent wildfires sent a shockwave around the world – and prompted many building owners to take pre-emptive action against future events. But what exactly can you do to combat the impact of wildfires?
This article leverages our building health experts’ insights to explain how HVAC systems can form a vital defense against wildfire smoke – and keep occupants safe during and after such events.
The True Impact of Wildfire Smoke on Building Occupant
We all understand how devastating wildfires can be, but research captures the true scale of the problem across multiple areas:
- Health Damage: Over 1.5 million deaths each year are attributed to harmful exposure caused by wildfires, while many more experience impairments to their cognitive faculties – as well as painful burns and other injuries.
- Environmental Impact: Wildfires burn twice as much tree cover as they did 20 years ago, with the total annual cover loss increasing by 6 million hectares since 2001. Worse still, experts estimate wildfires add 8 tonnes of CO2 to the atmosphere each year.
- Economic Loss: In California alone, property damage from wildfires is estimated around $250 billion; the economic impact of lives lost due to exposure to wildfires adds another $456 billion.
Notably, these effects are not exclusive to those directly affected by wildfires. Smoke can reach nearby buildings and compromise air quality – often without occupants realizing. Fine particulate matter (PM2.5) from smoke enters the indoor environment and causes a range of health problems:
- Short-term exposure can cause respiratory irritation, coughing, shortness of breath, and worsen conditions like asthma and chronic obstructive pulmonary disease (COPD).
- Long-term exposure is linked to increased risks of cardiovascular diseases, stroke, lung cancer, and reduced lung function.
Without the right systems in place to identify and mitigate PM2.5 exposure, building occupants’ safety will be compromised – which is why optimized HVAC systems are so important.
HVAC Systems: A Surprising Defense Against Wildfire Smoke
Your HVAC system is the first line of defense against all air pollution issues – and there are five ways you can use it to combat wildfire smoke:
1. Upgrade Air Filtration to Capture Fine Particles
Ensuring clean indoor air during wildfire events starts with enhancing filtration efficiency. There are two critical steps to upgrading HVAC air filtration:
- Install High-Efficiency Filters: The most effective way to prevent wildfire smoke from compromising indoor air quality is to use high-efficiency filters in HVAC systems. Filters rated MERV 13 or higher can effectively capture up to 90% of PM2.5 particles, which are the most harmful components of wildfire smoke.
- Check and Replace Filters More Frequently: Wildfire smoke leads to rapid filter clogging, reducing their efficiency and overburdening HVAC systems. Instead of the usual quarterly filter replacements, facilities should inspect filters every few days during wildfire events. Upgrading to a two-stage filtration system, with pre-filters capturing larger debris, can extend the lifespan of fine particle filters and maintain optimal performance.
2. Adjust Ventilation to Limit Smoke Infiltration
Proper ventilation control is key to limiting the infiltration of wildfire smoke. Adjust your HVAC system to minimize exposure by recirculating air and maintaining positive air pressure:
- Switch to Recirculation Mode: When wildfire smoke is present, HVAC systems should be set to recirculate indoor air to prevent outdoor contaminants from entering. Adjusting systems to minimize outdoor air intake, unless required by ventilation regulations, helps keep indoor environments safer.
- Pressurize the Building: Positive air pressure can be used to keep wildfire smoke from seeping indoors by controlling make-up air units and minimizing leakage through doors and windows. Utilizing dampers and economizers in HVAC units can further seal off smoke entry points, ensuring a controlled indoor atmosphere.
3. Use Air Purification and Additional Filtration
Filtration alone may not be enough during severe wildfire events. Supplement HVAC filtration with air purification technologies can further enhance indoor air quality:
- Integrate HVAC-Compatible Air Purifiers: In-duct air purifiers such as HEPA filtration units, UV-C light systems, or bipolar ionization devices can enhance air cleaning efficiency.
- Deploy Standalone HEPA Purifiers: For additional protection in high-occupancy areas, portable HEPA air purifiers should be used alongside HVAC filtration. For buildings exposed to prolonged smoke, activated carbon filters within HVAC systems can absorb volatile organic compounds (VOCs) and smoke-related odors, which standard MERV filters alone cannot eliminate.
4. Maintain Optimal Humidity and Airflow
Humidity and airflow play an essential role in reducing airborne contaminants from wildfire smoke:
- Control Humidity to Reduce Smoke Particles: Maintaining indoor humidity levels between 40-60% helps reduce airborne contaminants by allowing smoke particles to settle faster, minimizing inhalation risks.
- Optimize Air Circulation: Ensuring continuous HVAC fan operation during wildfire events is crucial for keeping air filtered and preventing stagnant smoke pockets indoors. Experts recommend running fans at low speeds even when heating or cooling is not needed, as this keeps particulates moving toward filters for efficient removal.
5. Monitor and Automate Air Quality Management
Use smart technology and automation to ensure your HVAC systems respond dynamically to changing air quality conditions:
- Install IAQ Sensors in the HVAC System: Integrating indoor air quality (IAQ) sensors allows real-time monitoring of PM2.5, CO2, and VOC levels within a building. These sensors can automatically adjust filtration or ventilation settings based on air quality fluctuations.
- Use Smart HVAC Controls: Smart building management systems (BMS) can dynamically optimize HVAC operations, adjusting airflow, filter efficiency, and purification modes in response to air quality data. Equally, scheduling HVAC maintenance before wildfire season ensures systems are clean, properly sealed, and prepared to handle smoke-related challenges.
These five strategies turn your HVAC systems into a vital defence against indoor exposure to wildfire smoke – safeguarding occupant health and maintaining safe air quality levels even during prolonged wildfire events. But many building owners and operators will find this overwhelming; that’s why NEBB exists to connect you with HVAC experts.
NEBB certification is the international gold-standard for testing, adjusting, and balancing (TAB) professionals. Working with a NEBB-certified TAB expert will make optimizing your HVAC to combat wildfires simple – while producing best-in-class results.
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