Video: Scented Products in Homes Cause Pollution, Requiring Air Changeouts

Recent breakthrough research from Purdue University should put every HVAC contractor on alert: common household products are creating indoor air pollution that far exceeds outdoor levels, highlighting an urgent need for advanced ventilation solutions.

In new studies conducted in Purdue’s specialized residential lab, engineers discovered that everyday scented products—from wax melts to air fresheners—generate nanoparticles at rates that match or exceed emissions from both gas stoves and vehicle engines.

“To understand how airborne particles form indoors, you need to measure the smallest nanoparticles — down to a single nanometer,” explains Dr. Brandon Boor, Purdue’s Dr. Margery E. Hoffman Associate Professor in Civil Engineering. “At this scale, we can observe the earliest stages of new particle formation, where fragrances react with ozone to form tiny molecular clusters. These clusters then rapidly evolve, growing and transforming in the air around us.”

The findings are stark: while a gas stove emits up to 100 times more nanoparticles than street-level car exhaust, scented products generate even higher levels of these potentially harmful particles.

Critical Implications for HVAC Professionals

“Our research shows that fragranced products are not just passive sources of pleasant scents — they actively alter indoor air chemistry, leading to the formation of nanoparticles at concentrations that could have significant health implications,” warns Dr. Nusrat Jung. “These processes should be considered in the design and operation of buildings and their HVAC systems to reduce our exposures.”

The research reveals several key considerations for contractors:

1. Particle Size and Filtration: The nanoparticles generated are extremely small—just a few nanometers in size—requiring sophisticated filtration solutions beyond standard MERV ratings.
2. Ozone Interaction: These pollutants form when fragrances react with ozone entering through ventilation systems, suggesting the need for strategic approaches to ozone management in HVAC design.
3. Exposure Rates: In just 20 minutes, scented product use can result in 100 billion to 10 trillion nanoparticles depositing in a person’s respiratory system, emphasizing the need for rapid air exchange rates.

Business Opportunities for Contractors

This research opens several revenue streams for HVAC professionals:

• System Upgrades: Existing systems may need modifications to handle these newly understood pollution sources
• Advanced Filtration: Opportunity to install and maintain higher-grade filtration systems
• Monitoring Solutions: Installation of real-time air quality monitoring systems
• Maintenance Programs: Development of specialized maintenance programs focusing on indoor air quality
• Consulting Services: Advising clients on ventilation strategies when using scented products

Technical Solutions to Consider

For commercial and residential applications, contractors should evaluate:

• Enhanced ventilation rates during peak usage periods
• Multi-stage filtration systems
• Air quality monitoring integration
• Strategic placement of supply and return vents
• Advanced control systems for automated ventilation adjustment

Looking Ahead

“Indoor air quality is often overlooked in the design and management of the buildings we live and work in, yet it has a direct impact on our health every day,” notes Dr. Boor. This oversight presents a significant opportunity for HVAC professionals to position themselves as essential partners in creating healthier indoor environments.

The unregulated nature of indoor air quality, combined with these new findings about everyday chemical products, creates an urgent need for HVAC expertise. Contractors who understand and can address these emerging concerns will be well-positioned to provide solutions that go beyond traditional temperature control, focusing on comprehensive air quality management that protects occupant health.