Talking Air Filtration

In this episode of the NAFA Podcast, recorded live at NAFA’s 2025 Technical Seminar, Dr. Joseph Allen, Director of the Healthy Buildings Program at Harvard T.H. Chan School of Public Health, delivers a compelling keynote on why healthy buildings are central to public health, productivity, and safety.Dr. Allen explores how cleaner air improves cognitive function, why outdated ventilation standards fail to protect people, and how the COVID-19 pandemic reshaped the science and policy of indoor air. He shares actionable strategies for building owners, engineers, employers, and policymakers to improve indoor environments through better ventilation, filtration, and design standards.Listeners will learn about the history of ventilation standards, the breakthrough shift in recognizing airborne transmission of COVID-19, the movement toward health-based ventilation targets, and the rise of low-cost indoor air monitoring tools that are transforming accountability in buildings worldwide.Whether you work in air filtration, facilities management, public health, or are simply curious about the air you breathe, this episode offers practical takeaways and a vision for the future of healthy buildings.00:00 – 00:31Introduction to the NAFA Podcast and its mission.00:31 – 01:05Overview of the episode: Dr. Joseph Allen on the science and business case for cleaner indoor air.01:05 – 01:28Practical steps for professionals, employers, and policymakers to improve indoor environments.01:28 – 02:02Acknowledgments to NAFA and opening remarks.02:02 – 03:02Audience quiz on indoor air and how much time people spend indoors (90%).03:02 – 04:13Why buildings are missing from decades of public health studies and why this gap matters.04:13 – 05:34Quiz continues: ventilation standards, particle exposure, and how much air comes from others in the room.05:34 – 06:09Introduction to strategies for reducing respiratory disease indoors.06:09 – 07:12Buildings as frontline tools during pandemics and early COVID-19 insights.07:12 – 09:14Making the case for airborne transmission during the pandemic and why recognition was delayed.09:14 – 10:24Modeling airborne transmission and demonstrating how ventilation and filtration reduce spread.10:24 – 11:09Breaking into top medical journals and shifting decades of assumptions about transmission.11:09 – 12:28The “first four healthy building strategies”: commissioning, ventilation, filtration, and portable air cleaners.12:28 – 13:24Portable air cleaners: effectiveness, placement, and the importance of mixing.13:24 – 14:38Why airflow and mixing are critical to reducing infection risks.14:38 – 15:29The challenge of setting health-based ventilation targets—moving beyond “acceptable” standards.15:29 – 16:51Historical perspective: ventilation targets in the 1800s and how they regressed in the 1970s.16:51 – 18:10COVID-19 guidance: 4–6 air changes per hour and the need for clear targets.18:10 – 19:56Consensus building: Lancet Commission and the push toward 30 CFM/person or 5 ACH.19:56 – 21:14Adoption of new standards by ASHRAE, CDC, and state health departments.21:14 – 22:22A major turning point: reframing ventilation as a cornerstone of public health.22:23 – 23:14NAFA certifications and professionalism in air filtration.23:14 – 24:18Public awareness shift: indoor air quality on the front page of The New York Times and 60 Minutes.24:18 – 26:01Technology shift: rise of low-cost air quality monitors and their impact on accountability.26:01 – 27:34The public’s new ability to “interview” buildings and the power shift in knowledge.(Episode continues with additional research insights and closing commentary.)Episode Timestamps

Host Tony Veroeven introduces the topic of air filtrationand welcomes guests Jim and Patrick Rosenthal from Tex Air Filters.[02:15] Jim's Journey in Air FiltrationJim Rosenthal shares the history of Tex Air Filters,starting in 2000, and the challenges and growth they experienced.[05:30] The Importance of NAFADiscussion on the role of the National Air FiltrationAssociation (NAFA) in the industry and its benefits for businesses.[08:45] Patrick's Involvement and Sales InsightsPatrick Rosenthal talks about his entry into the familybusiness and the unique aspects of selling air filters.[12:00] Industry Changes Post-PandemicJim and Patrick discuss how the pandemic affected the airfiltration industry, particularly the demand for MERV 13 filters.[15:30] Customer Education and ChallengesPatrick highlights the importance of understanding customerneeds and the common misconceptions about air filtration.[18:45] The Role of Collaboration in the IndustryThe guests discuss the collaborative nature of the industryand how it benefits all stakeholders.[22:00] Future Opportunities and ResearchInsights into future opportunities in the air filtrationindustry and the importance of research and development.[25:00] Closing RemarksTony wraps up the discussion, thanking Jim and Patrick fortheir insights and contributions to the industry.

In this episode, Kevin Delahunt presents his insights on HVAC design and maintenance, going beyond filter performance to explore reducing particulate load in occupied spaces, the importance of filter hardware, designing for extraordinaryevents, and more. Listeners will gain a comprehensive understanding of how to design and maintain HVAC filtration systems that not only meet current standards but also ensure the health and safety of building occupants.Practical insights and case studies will provide actionable steps for immediate implementation in their own projects.View Kevin’s presentation here. For detailed show notes, read below and use the timestamps to navigate the episode:[2:43] Kevin says there is an opportunity going forward to build messaging targeted toward engineers, designers, and other industry experts. [3:52] One of the biggest problems facing the facility management industry is the “pandemic effect” – there is still a high vacancy rate in many facilities. As people return to the office, they have questions about how safe the air they’re breathing is. [6:16] How did we get to MERV 13? To reduce the spread of infectious disease, ASHRAE suggests mechanical filterefficiency should be MERV 13 or higher.[9:49] The pandemic has emphasized hardware issues. Filter hardware has not kept pace with filter technology.Additionally, physical units lack space to upgrade to better filters.[16:40] If it doesn’t fit, it doesn’t filter. 100% of the air needs to go through the filter for it to perform effectively. [17:50] There are 130,000 K-12 schools in North America, with an average age of 50. Each of these schools has an averageof 10 HVAC systems. 40% of those systems need to be replaced immediately.[20:30] In 2023, 15 million hectares were burnt in the Canada wildfires – about the size of Illinois. Filtration professionals could upgrade filters during wildfire season to account for this.[24:00] Commercial buildings collect data on air quality, but do not share that data. Kevin says that sharing air quality data could give businesses a competitive advantage.

The goal of effective inventory management is to “meet or exceed your customers’ expectations of product availability with the amount of each item that will maximize your net profitability.” In this session, Jon Schreibfeder explores how to achieve this goal. Learn how to determine customer expectations, decide what products to stock, ensure accurate replenishment lead times, and maximize profitability by buying high-quality products. View Jon’s presentation here.For detailed show notes, read below and use the timestamps to navigate the episode:[3:51] Improving your inventory management starts with turning your data into information. [6:13] Ranking is the process of classifying your data. The most common ranking method is to rank solely by cost of goods sold, but “best practice” is to factor in activity, profitability, and cost of goods sold. [10:30] Keeping an inventory is also about stocking products that your customers are asking for. To determine these products, look at usage in the last twelve months. [13:19] Jon argues that gross margin is a terrible metric for success. Gross margin does not factor in inventory. Jon recommends replacing or at least supplementing gross margin with adjusted margin, which factors for inventory carrying costs.[19:40] Based on US averages, it costs you somewhere between 14 and 26 cents for each dollar of inventory to carry your inventory. [25:13] Sometimes, unprofitable items can be bundled with profitable items. They may also be necessary for a service you provide. Other than these two cases, these items should be removed.[28:11] Your average forecast error should be under 25%. If it is above 25%, Jon suggests using a different methodology to forecast[34:34] Certain items in your inventory require more safety stock than others. This allows you to absorb unusually high sales of critical items. [37:58] For products with very consistent usage and lead times, you do not need to invest in safety stock. [44:03] A lot of your profits cannot be accurately forecasted. Most systems will try to calculate an average monthly usage from your data, but usage will fluctuate dramatically between months. [51:38] Your total inventory investment is not just your core inventory; you also need to budget for a speculative inventory, which will include new products. 

The air filtration landscape has shifted significantly since the pandemic. In this presentation, Kyle Megna of Air Things discusses the transformative impact of the pandemic on indoor air quality. He examines the latest trends in IAQ data, reviews critical legislative updates, highlights new funding avenues, and analyzes market shifts that are influencing both residential and commercial spaces.View Kyle’s presentation here.For detailed show notes, read below and use the timestamps to navigate the episode:[2:01] The COVID-19 pandemic has led to the most engagement that we have seen in air quality for over fifty years. The pandemic taught us to mask, socially distance, and wash our hands; but people continued to get sick. [5:31] In 2021, 73% of people in the US say that their awareness of air quality has increased since the pandemic. However, only 26% of employers are making changes to their air filtration systems.[9:10] Air quality is improving, but 36% of Americans still live in places with failing grades for unhealthy levels of ozone or particle pollution.[10:53] Indoor air quality has worsened as a side effect of energy-efficient buildings. These buildings are airtight to prevent energy leakage, which also results in poor filtration. [13:21] Indoor C02 is getting worse in residential areas in the summer, while the curve is flatter for business spaces. [14:30] There is currently no legislation on indoor air quality at the federal levels, but many states are targeting air quality in schools. California’s CalSHAPE program incentivizes schools to update their HVAC systems. [18:00] Schools that receive the grants must monitor C02, and C02 is the only measure the state looks at. California has fallen short on outlining what happens when schools exceed the maximum C02 levels. [20:38] Kyle discusses the school air standards in Colorado, Maryland, and Oregon. [24:57] ESSER is essentially a blank check; there are few restrictions on spending ESSER funds. RENEW has more guidelines.[27:21] LEED is the most well-known of the programs, with version five changes coming in 2025. WELL is beginning to pick up in the US, offering a more holistic approach.