Air Quality Matters

This week, we examine a document that represents a profound shift in how we think about school environments: What if the debate over airborne transmission and clean air in schools is finally over—and the real fight is just beginning?

The document is titled Ventilation and Air Quality in Education and Childcare Settings, published on 24 February 2026 by the UK Department for Education. It applies specifically to England, and it codifies into official government guidance something we've been arguing about for years: that good ventilation is absolutely essential for healthy and productive learning environments. This isn't a theoretical discussion anymore. This is operational policy.

The guidance plainly states that effective ventilation does more than just prevent overheating. It improves pupils' alertness and concentration. It removes polluted air. And crucially, it removes air that might contain virus particles, reducing the spread of respiratory infections like colds, flu, and COVID-19. This is massive. It places the management of indoor air quality squarely in the realm of basic school health and safety.

Key Topics Discussed:

• The Monitoring Framework: Schools are expected to regularly monitor CO2 concentrations across their buildings. The guidance provides best practices on sensor placement—at head height or table height, at least half a meter away from people, and away from doors, windows, or ventilation outlets. If you're under 800 ppm, your ventilation is good. Between 800 and 1500 ppm, it's adequate but could be improved. Over 1500 ppm, your ventilation is officially poor and you need to act.
• Pragmatic Winter Compromises: The guidance addresses the real-world conflict between keeping kids warm and keeping their air clean. Partially open windows, open higher-level windows to reduce drafts, air out rooms for 10 minutes every hour during breaks. But crucially, do not prop fire doors open to get cross ventilation.
• Beyond CO2: The document talks about multifunctional environmental sensors that can track temperature, humidity, particulate matter like PM2.5 and PM10, and volatile organic compounds from sources like formaldehyde, cleaning chemicals, body odors, and vaping products. Yes, they specifically mention monitoring for vapes.
• Air Cleaning Units—With Massive Caveats: The Department for Education is crystal clear that while air cleaning units reduce airborne contaminants including viruses, bacteria, and fungal spores, they do absolutely nothing to improve ventilation or lower CO2 levels. They are not a substitute for ventilation. The government only recommends HEPA filtration units—subtractive technology that physically catches pollutants. They explicitly reject air ionizers, ozone generators, and units with unenclosed UV fields.
• The Funding Sting: Between 2021 and 2023, the Department for Education provided CO2 monitors and air cleaning units to all state-funded education settings. But now, in 2026, the guidance explicitly states that the government will not replace faulty or damaged devices, and they will not pay for replacement filters. The ongoing financial burden of maintaining clean air has been shifted entirely onto individual school budgets.
• The Controversial Bits: The guidance talks about bringing in fresh outdoor air—a phrase doing a lot of heavy lifting when many schools are backed up against busy roads. It standardizes on NDIR CO2 sensors, which are solid but arguably already behind the times compared to photoacoustic sensors. And that 1500 ppm threshold—many in our community will argue that allowing CO2 levels anywhere near 1500 ppm is simply not acceptable for vulnerable populations.

Ventilation and Air Quality in Education and Childcare Settings UK Department for Education, 24 February 2026

https://www.gov.uk/government/publications/ventilation-and-air-quality-in-education-and-childcare-settings/ventilation-and-air-quality-in-education-and-childcare-settings

The One Take Podcast in Partnership with

SafeTraces (https://www.safetraces.com/) and Inbiot (https://www.inbiot.es/?utm_campaign=simon&utm_source=airqualitymatters&utm_medium=podcast)

Do check them out in the links and on the Air Quality Matters Website (https://www.airqualitymatters.net/podcast)

• 00:00:00 Introduction: The UK's New School Air Quality Guidance
• 00:01:15 The Science Is Settled: Air Quality as Basic Health and Safety
• 00:02:16 The Monitoring Solution: CO2 as Your Ventilation Indicator
• 00:03:19 The Traffic Light System: Understanding CO2 Thresholds
• 00:04:03 Winter Pragmatism: Balancing Warmth and Fresh Air
• 00:04:46 Beyond CO2: Multifunctional Environmental Sensors
• 00:05:36 Air Cleaning Units: The Promise and the Limitations
• 00:06:39 HEPA Only: The Government's Firm Stance on Technology
• 00:07:41 The Sting in the Tail: Who Pays for Ongoing Maintenance
• 00:08:56 The Uncomfortable Details: Fresh Air, NDIR, and 1500 PPM
• 00:10:41 The Bottom Line: Science Won, Now the Funding Battle Begins

This week, we sit down with Stephanie Taylor, a unique physician architect whose career is dedicated to bridging the deep chasm between the medical profession and the built environment, to explore a question that fundamentally challenges how we think about buildings: What if the real problem isn't just that our buildings are failing us—but that we're measuring the wrong things entirely?

As medical advisor for ThinkLite Air, she applies her clinical insights to the development of advanced air sensing and cleaning technology, transforming raw environmental data into actionable health impact scores. By integrating medical science into engineering standards, she continues to champion the idea that engineers are in many ways the physicians of the future, responsible for the preventative care of billions of people who spend so much of their time indoors.

Key Topics Discussed:

• Buildings as Extensions of Health: Why treating buildings as part of caring for human health could be one of the biggest advances of our century. The opportunities are clear: decreased acute and chronic diseases, improved productivity, better financial outcomes. But will we actually do it? The obstacles include resistance to change, difficulty bringing the medical community into building management, and the legal ramifications of talking about health.
• Defining the Finish Line: What does good indoor environmental health actually look like? Stephanie's answer: an indoor space that does not increase our physiological stress level. Not just measuring hazards, but diminishing components of the indoor environment that cause stress on our cardiovascular, respiratory, neurological, and immune systems.
• The Imperceptible Forces Problem: We design buildings and respond to environments as we can perceive them—rain, cold, visible mould. But the imperceptible exposures are the ones causing us problems. Low humidity impairing immunity. Ultrafine particles penetrating deep into the lungs. VOCs we cannot smell. The challenge is monitoring and controlling what we cannot sense.
• The Platinum Building Paradox: Why even the most advanced buildings with all the badges can fail spectacularly. A healthy buildings conference held in a room where 100 experts sat in a fog of their own breath for four hours, CO2 climbing to 3,000 parts per million in one of the smartest buildings in London. The disconnect between design intent and operational reality.
• Beyond Wells Riley: Rethinking how we model risk. The traditional Wells Riley equation models exposure to infectious bioaerosols. Stephanie is expanding that framework to model not only exposure risk, but also what indoor air quality is doing to your immune system—your protective mechanisms. It's not just how many weapons are shooting at you, but your ability to defend yourself.
• ThinkLite and the Health Index: Seeing what's going on through sensors, analyzing the data in a way that is relevant for the human body system by system—lungs, brain, cardiovascular health—and then remediating. Turning arbitrary data points into relevant health metrics. Moving from zigzag lines on dashboards to actionable health impact scores

GUEST:

Stephanie Taylor

Physician Architect | ASHRAE Fellow | Medical Advisor, ThinkLite Air

Stephanie Taylor - LinkedIn https://www.linkedin.com/in/stephanie-taylor-md-b6456b8/

https://www.thinkliteair.com/

The Air Quality Matters Podcast in Partnership with

Particles Plus https://particlesplus.com/

Farmwood (https://farmwood.co.uk/) - Eurovent (https://www.eurovent.eu/) - Aico (https://www.aico.co.uk/) - Ultra Protect (https://www.ultra-protect.co.uk/air-quality-matters)

The One Take Podcast in Partnership with

SafeTraces (https://www.safetraces.com/) and Inbiot (https://www.inbiot.es/?utm_campaign=simon&utm_source=airqualitymatters&utm_medium=podcast)

Do check them out in the links and on the Air Quality Matters Website. (https://www.airqualitymatters.net/podcast)

If you haven't checked out the YouTube channel its here (https://www.youtube.com/@airqualitymatters-SimonJones). Do subscribe if you can, lots more content is coming soon.

• 00:00:00 Introduction: Buildings as an Extension of Human Health
• 00:06:42 The Medical-Building Disconnect: Why Healthcare Must Join the Conversation
• 00:12:17 Defining the Finish Line: What Does a Healthy Building Actually Look Like?
• 00:23:29 The Imperceptible Hazards: Why We Design for What We Can Sense
• 00:27:38 The Autonomic Building: Automation as an Extension of Human Physiology
• 00:33:27 The Platinum Building Paradox: When Award-Winning Spaces Fail Their Occupants
• 01:01:43 The Legal Minefield: Why Talking About Health Is Terrifying for Building Professionals
• 00:51:23 Think Light Air: Translating Environmental Data into Human Health Impact Scores
• 01:40:37 Beyond Wells-Riley: Modeling Vulnerability, Not Just Exposure
• 01:28:54 The Path Forward: Regulation, Education, and the Courage to Do the Hard Thing

This week, we tackle a question that cuts through decades of technical progress and scientific consensus: What if the reason we still don't have clean indoor air isn't because we lack the technology—but because we lack the policy to actually implement it?

The paper is a policy commentary titled Federal and State Policy Opportunities to Improve Indoor Air Quality, published in the Journal of Health Security. It's authored by a powerhouse group of experts, including Georgia Lagoudas and colleagues from Brown University, Harvard, and several other leading institutions. Many of them have been previous guests on this podcast. This isn't a theoretical exercise. It's a roadmap—a practical, actionable menu of policy interventions that could finally bring indoor air quality into the same regulatory and public health framework that we've successfully built for drinking water, fire safety, and smoking bans.

Here's the glaring truth: we spend about 90% of our time indoors, yet we have no unified national initiative for clean indoor air. We have the Clean Air Act. We have the EPA regulating outdoor air. But outdoor regulations completely fail to account for the fact that outdoor pollutants make their way inside—where we spend all our time—and they ignore the fact that indoor spaces have their own unique pollutant sources. Concentrations of certain pollutants can be two to five times higher indoors than outdoors. And outdoor regulations do absolutely nothing to address one of the biggest indoor threats: the spread of respiratory pathogens like COVID-19 and influenza.

Key Topics Discussed:

• The Current Mess: The federal government doesn't really regulate indoor air outside of occupational settings, leaving jurisdiction to state and local governments. Building codes are adopted and enforced locally, creating a massive patchwork of different standards. Some states like California, Connecticut, and Minnesota have taken steps, especially for schools, but there's no comprehensive national roadmap.
• Develop Health-Based Indoor Air Quality Targets: Right now, building owners and facility managers don't have a simple unified goal. We need clear thresholds for easy-to-measure indicators like carbon dioxide and PM2.5. The EPA or a coalition of NGOs should publish voluntary health-based targets, providing a clear benchmark that states and local entities can adopt. If you don't know what the target is, you can't hit it.
• Support States and Local Communities to Adopt Standards: Develop a national model indoor air quality code—similar to national model energy codes. Provide tax incentives to commercial buildings that make indoor air quality improvements, similar to deductions for energy efficient buildings. Create a state playbook filled with template language for regulations and building codes to make it easy for local governments to take action.
• Implement Sector-Specific Standards: Schools need indoor air quality monitors, regular HVAC inspections, and better filtration. Nursing homes should have indoor air quality standards as a strict condition of participation, just like hospitals. Federal buildings housing around a million federal employees need robust ventilation verification programs. OSHA needs to update its permissible exposure limits—many were developed in the 1970s, nearly half a century ago.
• The Two Biggest Priorities: Developing health-based indoor air quality targets and getting states to adopt indoor air quality building standards. If we can agree on what good air looks like and put it into the building code, the market will innovate to meet those demands.

Federal and State Policy Opportunities to Improve Indoor Air Quality

10.1177/23265094251410880 (https://doi.org/10.1177/23265094251410880)

The One Take Podcast in Partnership with

SafeTraces (https://www.safetraces.com/) and Inbiot (https://www.inbiot.es/?utm_campaign=simon&utm_source=airqualitymatters&utm_medium=podcast)

Do check them out in the links and on the Air Quality Matters Website (https://www.airqualitymatters.net/podcast)

• 00:00:00 Introduction: The Missing Framework for Clean Indoor Air
• 00:01:12 The Glaring Gap: Why Indoor Air Quality Has Been Ignored
• 00:01:45 Why Outdoor Regulations Fail Indoors
• 00:02:22 The Astronomical Cost of Inaction
• 00:03:01 The Current Mess: A Patchwork of Standards
• 00:03:55 Recommendation One: Health-Based Indoor Air Quality Targets
• 00:04:43 Recommendation Two: Supporting States with Standards and Financing
• 00:05:38 Recommendation Three: Sector-Specific Standards
• 00:07:13 Recommendation Four: Research and the Wild West of Air Purifiers
• 00:08:30 The Bottom Line: Clean Air Is a Choice We Must Make

This week, we sit down with Frank Kelly, Professor at Imperial College London and Director of the Environmental Research Group, to examine a question that fundamentally challenges how we think about air pollution: What if the real danger isn't just how much dust we're breathing, but what that dust is made of and what it does to our bodies at a cellular level?

For over three decades, Frank Kelly has been one of the architects of London's modern understanding of air quality. His pioneering work on the oxidative potential of particulate matter has transformed how we evaluate the toxicity of everything from diesel exhaust to wood smoke. By proving how these pollutants trigger harmful free radical reactions and deplete antioxidants in the lungs, he provided the scientific backbone for London's most ambitious public health interventions, including the Congestion Charging Zone and Ultra Low Emissions Zone.

Key Topics Discussed:

• Beyond Size and Mass: Why PM10, PM2.5, and ultrafine particles are categorized by size, but size alone doesn't tell us what's actually harmful. The real story is in the chemistry, the physics, and the biology of what those particles carry and what they do when they reach the lung.
• The Meteor Analogy: Particulate matter isn't just carbon spheres. It's a complex, ever-changing cocktail of metals, gases, chemicals, and biological material that picks up and sheds components as it moves through the environment and into our bodies.
• Oxidative Potential: What free radicals are, why transition metals on particle surfaces drive oxidative stress, and how the body's antioxidant defences like glutathione, vitamin C, and vitamin E fight back. When the balance tips, inflammation and cellular damage begin.
• The Seesaw Model: On one side, you have particulate pollution with oxidative potential. On the other, your body's natural defences. Your genetics, your diet, and your environment all determine where you sit on that seesaw and when the damage starts.
• The London Success Story: How Frank's research directly influenced the introduction of the Ultra Low Emissions Zone. The data showed that children living in East London exposed to heavy traffic pollution had slower lung growth than children outside London. That evidence became the catalyst for policy change.
• Indoor Air Quality and the Well Home Study: Over 100 homes in West London instrumented for two months each to understand indoor pollution sources. The findings: damp and mould in social housing, gas cooking as a major pollutant source, and pollution migrating from kitchens into children's bedrooms where it stayed trapped overnight.
• The Microplastics Problem: Modern tyres are 55% plastic. As the fossil fuel industry loses its market in surface transport, it's shifting to plastic production. Frank's team has developed methods to characterize plastic particles in air, water, and food. The challenge: distinguishing plastic signatures from human tissue in toxicology studies.
• The Future of Air Quality Monitoring: Moving beyond mass-based metrics to real-time oxidative potential monitoring. Frank's team is developing prototype instruments that measure free radical activity in the air instantaneously, allowing us to identify which pollution sources are truly harmful.

GUEST:

Frank Kelly

Professor, Imperial College London | Director, Environmental Research Group

https://www.imperial.ac.uk/people/frank.kelly

The Air Quality Matters Podcast in Partnership with

Particles Plus https://particlesplus.com/

Farmwood (https://farmwood.co.uk/) - Eurovent (https://www.eurovent.eu/) - Aico (https://www.aico.co.uk/) - Ultra Protect (https://www.ultra-protect.co.uk/air-quality-matters)

The One Take Podcast in Partnership with

SafeTraces (https://www.safetraces.com/) and Inbiot (https://www.inbiot.es/?utm_campaign=simon&utm_source=airqualitymatters&utm_medium=podcast)

Do check them out in the links and on the Air Quality Matters Website. (https://www.airqualitymatters.net/podcast)

If you haven't checked out the YouTube channel its here (https://www.youtube.com/@airqualitymatters-SimonJones). Do subscribe if you can, lots more content is coming soon.

• 00:00:00 Introduction: The Hidden Complexity of Particulate Matter
• 00:05:50 Understanding PM10, PM2.5, and Ultrafine Particles
• 00:08:01 The Lung as an Open Door: Why We're Vulnerable
• 00:09:52 The Meteor Effect: What Particles Are Really Made Of
• 00:20:41 The Seesaw Battle: Oxidative Potential and Free Radicals
• 00:25:46 The London Laboratory: Evidence That Drove the Ultra Low Emission Zone
• 00:59:13 The Indoor Air Quality Challenge: A New Frontier
• 01:11:43 The Kitchen Problem: Why Cooking Dominates Indoor Pollution
• 01:26:46 The Research Ecosystem: Eight Teams Tackling Air Quality
• 01:44:51 The Future: Real-Time Oxidative Potential Monitoring

This week, we dive into a question that challenges one of the most common assumptions in building energy efficiency: What if the chemical tests we use to validate air cleaning technology are completely missing the point—and what if the human nose is actually the most reliable instrument we have?

The paper is titled A Method for Testing the Gas Phase Air Cleaners Using Sensory Assessment of Air Quality, published in the Journal of Building and Environment. It's authored by Cantor Amada, Lee Fang, Pavel Wargocki, and colleagues from Waseda University in Japan and the Technical University of Denmark. This research was conducted as part of the IEA Energy and Buildings and Communities Annex 78 project, and it proposes a radically practical testing protocol for gas phase air cleaners—one that puts human perception at the center, not just chemical spreadsheets.

But here's the problem. Current standards typically test these air cleaners by challenging them with a few selected chemicals—measuring how well they remove formaldehyde, for example. But indoor air contains hundreds of different gaseous pollutants. If you only use chemical analysis on a handful of compounds, you might completely underestimate real-world performance. Worse, you might completely miss harmful byproducts the air cleaner is actually creating.

Key Topics Discussed:

• Subtractive vs. Additive Air Cleaners: Subtractive cleaners remove chemicals using things like activated carbon. Additive cleaners decompose chemicals using active components like photocatalytic oxidation, ion generators, UV, or ozone. Some additive technologies can transform relatively harmless pollutants into dangerous unwanted species—or pump ozone into the space. If your chemical test isn't looking for those specific byproducts, the machine gets a pass grade while actively making the room worse.
• The Two-Phase Testing Protocol: Phase one is a screening phase—do no harm. The goal is simply to make sure the air cleaner doesn't have a negative effect on air quality. Phase two is the deep dive, testing the air cleaners at various ventilation rates from very low to standard levels, with panelists rating acceptability and odor intensity.
• The UVO Zone Device Failed Immediately: One additive air cleaner—a UVO zone device—actually increased the odor intensity in the room, particularly when humans were present. It was dropped from the study. An ion generator was allowed through to phase two just to see if poor results would be repeated. They were. It significantly decreased the acceptability of the air.
• Activated Carbon Worked—But Only for Building Materials: When the pollution source was purely building materials like old carpets and linoleum, the activated carbon air cleaners significantly improved air quality. But when the pollutant source was humans—people just sitting there breathing and existing—the air cleaners did not significantly improve perceived air quality.
• The Chemical Data Lied: Parallel chemical measurements showed that total VOCs dropped significantly when using the carbon air cleaners, regardless of whether the pollutant came from materials or humans. If you were only looking at the chemical spreadsheet, you would say the air cleaners worked perfectly in all scenarios. But the human panelists were telling a completely different story. The chemical measurements simply did not match the sensory evaluations.
• The ISO 16000-44 Standard: This research heavily supports the new ISO 16000-44 standard approved in 2023, which outlines the test method for measuring perceived indoor air quality to test the performance of gas phase cleaners. The sector is slowly recognizing that the human experience is a metric.

A Method for Testing the Gas Phase Air Cleaners Using Sensory Assessment of Air Quality

https://doi.org/10.1016/j.buildenv.2024.111630

The One Take Podcast in Partnership with

SafeTraces (https://www.safetraces.com/) and Inbiot (https://www.inbiot.es/?utm_campaign=simon&utm_source=airqualitymatters&utm_medium=podcast)

Do check them out in the links and on the Air Quality Matters Website (https://www.airqualitymatters.net/podcast)

• 00:00:00 Introduction: The Challenge of Testing Gas Phase Air Cleaners
• 00:01:14 The Energy Dilemma: Why Air Cleaners Matter for Buildings
• 00:02:12 The Chemical Testing Problem: What Current Standards Miss
• 00:02:53 Additive vs Subtractive: Understanding Air Cleaner Technologies
• 00:03:43 The Human Nose Solution: Sensory Assessment as a Testing Method
• 00:04:04 The Experimental Setup: Real Materials and Real People
• 00:04:50 Phase One Results: The Do No Harm Screening
• 00:05:54 Phase Two Deep Dive: Testing at Various Ventilation Rates
• 00:06:31 The Big Reveal: When Chemical Data Doesn't Match Human Experience
• 00:07:28 The Massive Implication: Why Chemical Analysis Alone Fails
• 00:08:21 The Path Forward: ISO 16000-44 and Sensory Testing Standards
• 00:09:24 Closing Thoughts: The Human Nose Remains Essential

This week, we sit down with Mark Lynn, Managing Director of Eden Renewable Innovations and Chair of the Alliance for Sustainable Building Products, to explore a question that cuts to the heart of indoor air quality: What if the materials we bring into our buildings are the forgotten foundation of healthy indoor air—and what if natural materials offer solutions we've systematically overlooked for decades?

Recorded live at the Alliance for Sustainable Building Products Annual Healthy Buildings Conference in London, this conversation takes us deep into the world of building materials, their chemistry, their moisture behavior, and their profound impact on the air we breathe indoors. Mark brings over two decades of experience in natural fiber insulation and nearly 30 years in natural building materials, with a particular focus on building physics and the chemistry of materials.

Key Topics Discussed:

• The Forgotten Inflection Point: In the mid to late 1990s, society cared deeply about indoor air quality. MDF was scrutinized for formaldehyde emissions. Smoking bans were introduced. Ventilation moved up the agenda. But somewhere around the early 2000s, we shifted our focus entirely to ventilation as the sole solution—and stopped asking hard questions about the materials themselves.
• The Chemical Experiment: A single 1970s living room contained perhaps a dozen materials, most locally sourced. Today's living rooms contain thousands of materials, sourced globally, with complex chemistries we barely understand. We are living in a grand chemical experiment, and the results won't be clear for decades.
• Hurdle Technology and the Swiss Cheese Model: Ventilation alone is not enough. Good indoor air quality requires multiple layers of defense—elimination of harmful materials at source, moisture buffering through hygroscopic materials like wood and wool, and only then, ventilation as a final backstop. Relying on ventilation alone assumes it works perfectly. It rarely does.
• The Moisture Problem: Ventilation removes 95% of moisture from a building. But the remaining 5% can cause catastrophic problems—mold, structural decay, and poor air quality. Natural materials like sheep's wool and wood fiber can buffer moisture safely, acting as a critical redundancy when ventilation underperforms.
• Wool and Formaldehyde: Sheep's wool uniquely reacts with formaldehyde through a condensation reaction, permanently binding the carbon from formaldehyde into the keratin protein structure of the fiber. It's not just inert—it's actively neutralizing a harmful indoor pollutant.

GUEST:

Mark Lynn

Managing Director, Eden Renewable Innovations | Chair, Alliance for Sustainable Building Products

https://asbp.org.uk/

https://thermafleece.com/

The Air Quality Matters Podcast in Partnership with

Particles Plus https://particlesplus.com/

Farmwood (https://farmwood.co.uk/) - Eurovent (https://www.eurovent.eu/) - Aico (https://www.aico.co.uk/) - Ultra Protect (https://www.ultra-protect.co.uk/air-quality-matters)

The One Take Podcast in Partnership with

SafeTraces (https://www.safetraces.com/) and Inbiot (https://www.inbiot.es/?utm_campaign=simon&utm_source=airqualitymatters&utm_medium=podcast)

Do check them out in the links and on the Air Quality Matters Website. (https://www.airqualitymatters.net/podcast)

If you haven't checked out the YouTube channel its here (https://www.youtube.com/@airqualitymatters-SimonJones). Do subscribe if you can, lots more content is coming soon.

• 00:00:00 Introduction: The Forgotten Fundamentals of Building Materials
• 00:02:19 The Inflection Points: When We Cared About Indoor Air Quality
• 00:05:16 The Chemical Soup: Living Rooms Then and Now
• 00:08:16 The Grand Chemical Experiment: Unknown Long-Term Impacts
• 00:10:58 Custodianship and Consumption: The Lost Art of Make Do and Mend
• 00:13:07 Particles as Trojan Horses: The Chemistry Happening in Your Home
• 00:15:22 Hurdle Technology: The Swiss Cheese Approach to Risk Management
• 00:17:34 Learning from Food: Why Digestive Biscuits Have Better Moisture Science
• 00:20:15 The Ventilation Fallacy: What Happens When Your Backup Plan Fails
• 00:25:00 Natural Technology: The Evolution Already Solved the Problem
• 00:32:59 The Standards Dilemma: Innovation Versus Established Frameworks
• 00:36:00 Post-Completion Reality: When Sensors Reveal the Truth
• 00:38:27 Transparency and AI: The Coming Revolution in Material Selection
• 00:57:59 Sheep's Wool and Formaldehyde: When Materials Fight Pollutants
• 01:01:20 The Trajectory Forward: Capacity, Policy, and Bottom-Up Change
• 01:04:39 From Belfast to Buildings: Optimism Through Experience

This week, we step outside the usual world of homes, schools, and offices to ask a question that might reshape how we think about the hospitality industry: What if the physical performance of a hotel room matters just as much as the quality of service—and what if guests are already telling us this in their online reviews?

The paper is titled The Impact of Indoor Environmental Quality on Tourist Accommodation Ratings Using Guest Reviews, published in the Journal of Building and Environment. It's authored by Fan Zhang and colleagues from Griffith University, the University of New South Wales, and several other international institutions. Using web mining and artificial intelligence, they analyzed over half a million Booking.com reviews from Australian hotels and serviced apartments to understand how indoor environmental quality—air quality, acoustics, thermal comfort, lighting—actually drives guest satisfaction and ratings.

Traditionally, measuring occupant satisfaction in hotels has been nearly impossible. Post-occupancy evaluations require structured surveys, but try getting a business traveler rushing to the airport at 6am to fill in a 20-page questionnaire about ventilation rates. It's just not going to happen. So instead, these researchers used natural language processing to extract the actual, unprompted words from guests who stayed in these places—to see exactly what they care about.

Key Topics Discussed:

• Three Factor Theory: A framework that categorizes any product or service feature into three buckets: basic factors (dissatisfiers), performance factors (the better it is, the happier you are), and excitement factors (unexpected bonuses). Almost all indoor environmental quality factors function as basic factors—guests expect them to be good, and if they're not, ratings plummet.
• The Big Three Failures: Poor cleanliness, poor indoor air quality, and bad acoustics were the specific failures that dragged accommodation ratings down the most. Stuffy rooms, musty smells, and hearing the elevator rattling through the walls all night are directly torching hotel revenues by driving down public ratings.
• Indoor Environmental Quality Accounts for 33% of Guest Ratings: In budget hotels, nearly a third of a customer's overall rating is driven by indoor environmental quality. In luxury accommodation, it's still about 24%. You can have the best marketing team and the friendliest staff, but if your building is fundamentally underventilated, your business will suffer.
• The COVID Effect: The pandemic drastically amplified our sensitivity to poor indoor environments. During COVID, the negative impact of poor indoor air quality and cleanliness on guest ratings got significantly stronger. People suddenly equated visible cleanliness and fresh air with their own personal safety and survival.
• The View Exception: In budget accommodation, a nice view was an excitement factor—people didn't expect it, so when they got one, they were thrilled. But in luxury hotels, the view reverted to being a basic factor. If you're paying 5-star prices, you expect 5-star views.
• The Case for IEQ Benchmarking: The researchers suggest that policymakers and industry leaders should implement formal indoor environmental quality benchmarking for hotels—similar to Australia's NABERS rating for office buildings. Imagine being able to check a hotel's certified ventilation and air quality rating before you even book a room.

The Impact of Indoor Environmental Quality on Tourist Accommodation Ratings Using Guest Reviews

https://doi.org/10.1016/j.buildenv.2025.113135

The One Take Podcast in Partnership with

SafeTraces (https://www.safetraces.com/) and Inbiot (https://www.inbiot.es/?utm_campaign=simon&utm_source=airqualitymatters&utm_medium=podcast)

Do check them out in the links and on the Air Quality Matters Website (https://www.airqualitymatters.net/podcast)

• 00:00:00 Introduction: The Overlooked Environment of Hotels
• 00:01:21 The Hospitality Blind Spot: Service vs Environment
• 00:01:52 The POE Problem: Why Traditional Surveys Fail in Hotels
• 00:02:24 The AI Solution: Mining Half a Million Guest Reviews
• 00:02:56 Three Factor Theory: The Framework for Understanding Buildings
• 00:04:06 The Eye-Opening Results: IEQ as a Basic Factor
• 00:05:03 The Triple Threat: Cleanliness, Air Quality, and Acoustics
• 00:05:44 The View Exception: Budget Thrills vs Luxury Expectations
• 00:06:30 The COVID Effect: When Air Quality Became Survival
• 00:07:53 The Bottom Line: IEQ Accounts for 33 Percent of Hotel Ratings
• 00:08:37 The Future: IEQ Benchmarking and Certification for Hotels
• 00:09:18 Study Limitations and the Reality of Guest Perception
• 00:09:55 The Main Takeaway: Engineering as Front-Line Business Survival

This week, we sit down with Adam Muggleton, Chief Technical Officer at AESG and host of the Edifice Complex Podcast.

Adam's career spans project management, property development, and commissioning across 21 countries—from the UK to the Middle East and North America. He views buildings not as architectural statements, but as complex machines that are likely underperforming. With decades of experience and zero patience for performative sustainability, he has developed a reputation for dismantling corporate jargon and shining a light on poor engineering and mediocre outcomes in the construction industry.

His relentless focus is on commissioning and building performance. He doesn't just want to know if a building looks good at sunset—he wants to know if the HVAC actually works, if the air is healthy, and why the industry persists in delivering glorified caves with modern price tags. Beneath his sceptical, no-nonsense exterior lies a deep advocacy for human-centric design, driven by the belief that the only way to fix the construction industrial complex is through radical transparency, rigorous testing, and a refusal to accept average as the industry standard.

Key Topics Discussed:

• The Commissioning Accident: How Adam fell into commissioning engineering by accident—and why commissioning is always an accident. No one wakes up at 16 and says they want to be a commissioning engineer. Yet it's one of the most critical roles in delivering functional buildings.
• The Consequences Problem: Why the construction industry is the only industry in the world where you can send out a set of documents riddled with errors and omissions—and not pay for those mistakes. Why there are no real consequences for poor delivery, and how that shapes everything from design to handover.
• Humans at the Centre of Buildings—A Waste of Time? A brutally honest discussion about whether the rhetoric of "humans at the center" actually matters when residential developers are at the bottom of the care chain, and the only real feedback that matters is whether people stop buying.
• The Elon Musk Question: Who is the Elon Musk of the built environment? Who is innovating, crushing it, doing the impossible? And why Adam's daughter and her engineering friends would rather flip burgers than work in the built environment.
• The Platinum Building Paradox: Why even high-performance buildings with all the badges can fail spectacularly—like a healthy buildings conference held in a room where everyone is sitting in a fog of their own breath because the ventilation can't handle 80 people.

GUEST:

Adam Muggleton - Chief Technical Officer, AESG | Host, Edifice Complex Podcast

https://www.linkedin.com/in/buildingwhisperer/

https://aesg.com/uk/

https://creators.spotify.com/pod/profile/edifice-complex-podcast2

The Air Quality Matters Podcast in Partnership with

Particles Plus https://particlesplus.com/

Farmwood (https://farmwood.co.uk/) - Eurovent (https://www.eurovent.eu/) - Aico (https://www.aico.co.uk/) - Ultra Protect (https://www.ultra-protect.co.uk/air-quality-matters)

The One Take Podcast in Partnership with

SafeTraces (https://www.safetraces.com/) and Inbiot (https://www.inbiot.es/?utm_campaign=simon&utm_source=airqualitymatters&utm_medium=podcast)

Do check them out in the links and on the Air Quality Matters Website. (https://www.airqualitymatters.net/podcast)

If you haven't checked out the YouTube channel its here (https://www.youtube.com/@airqualitymatters-SimonJones). Do subscribe if you can, lots more content is coming soon.

• 00:00:00 Introduction: The Accidental Commissioning Engineer
• 00:03:18 The Property Development Perspective: When Commissioning Becomes an Afterthought
• 00:04:50 The Consequence Problem: Why Construction Keeps Making the Same Mistakes
• 00:06:27 The Complexity Trap: Why Buildings Are So Difficult to Get Right
• 00:09:47 The Defects Dilemma: Cars vs Buildings and the Zero Defects Dream
• 00:10:51 The R&D Desert: Why Construction Firms Don't Invest in Innovation
• 00:15:49 The Building Hierarchy: Who Gets Good Air and Who Doesn't
• 00:19:09 The Human-Centric Building Myth: Why Residential Is at the Bottom
• 00:32:24 Breaking the Cycle: Commissioning as a Compliance Tool
• 00:51:19 The Supply Chain Reality: Who Really Designs Your Building
• 01:05:05 The Elon Musk Question: Where's the Innovation in Construction?
• 01:13:44 The Platinum Plaque Problem: High-Performance Buildings That Don't Perform
• 01:17:34 The Visibility Solution: Open Source Performance Data and Property Tax Penalties
• 01:20:41 The Housing Crisis: Why Government Must Get Back in the Game
• 01:37:35 The Optimistic Conclusion: Why Construction Is Still a Great Career

This week, we tackle a question that goes to the heart of the performance gap in buildings: What if the problem isn't just poor construction or shoddy installation—but the data we're feeding into our models in the first place?

There's an old saying in computer science: garbage in, garbage out. If you feed a perfect model with bad assumptions, you get a perfect calculation of a fantasy. And that's exactly what's been happening in indoor air quality modeling for decades. We've been relying on scattered, outdated, inconsistent emission rate data—pulled from 1990s conference papers, paywalled journals, and PDF reports buried in the internet—and wondering why our buildings don't perform as predicted.

The paper is titled Pandora: An Open Access Database of Indoor Pollutant Emission Rates for Indoor Air Quality Modeling, published in the Journal of Building Engineering. It's the work of a huge international team, including Mark Adobati and colleagues from Annex 86, and it represents a massive effort to clean up the mess of data that indoor air quality modelers have been struggling with for years.

Key Topics Discussed:

• The Data Problem: Why finding reliable emission rates for indoor pollutants has been a nightmare—scattered across thousands of sources, often in the wrong units, measured under weird conditions, and completely inconsistent.
• What Pandora Is: An open access, web-based database systematically compiling nearly 10,000 specific emission rates from the scientific literature, categorizing 740 different pollution sources—from paints and carpets to cleaning products, furniture, and even human beings.
• The Shocking Case Study: A simple child's bedroom modeled three different ways using data from Pandora. The total formaldehyde emission rate ranged from 342 micrograms per hour to over 6,000 micrograms per hour—a factor of 20 difference. If you designed ventilation based on the lower number, a trickle vent might be fine. Based on the higher number, you'd be installing industrial extraction.
• Why the Huge Discrepancy: The database contains data going back to the 1980s, when building materials were dirty—paints full of solvents, glues full of formaldehyde. Regulations like the French VOC label and German AGBB standard have forced manufacturers to clean up their act. If you use a statistical average of all data ever published, you're skewing your model with dirty data from 1995, predicting a problem that might not exist anymore.
• The Recommendation: Use the 25th percentile of the data for things like formaldehyde. This lower value is likely a much more accurate representation of modern, regulation-compliant materials. We might be systematically overestimating the chemical load from building materials if we rely on older datasets.

Pandora: An Open Access Database of Indoor Pollutant Emission Rates for Indoor Air Quality Modeling

https://doi.org/10.1016/j.jobe.2025.114216

Pandora Database: https://db-pandora.univ-lr.fr/

The One Take Podcast in Partnership with

SafeTraces (https://www.safetraces.com/) and Inbiot (https://www.inbiot.es/?utm_campaign=simon&utm_source=airqualitymatters&utm_medium=podcast)

Do check them out in the links and on the Air Quality Matters Website (https://www.airqualitymatters.net/podcast)

• 00:00:00 Introduction: The Data We Rely On
• 00:01:06 Garbage In, Garbage Out: The Input Data Problem
• 00:01:45 Introducing Pandora: A Massive Data Compilation Effort
• 00:02:27 The Scattered Data Nightmare: Why We Needed This
• 00:03:08 What's Inside: Construction Materials Dominate the Database
• 00:03:43 The Overlooked Sources: Cleaning Products and Human Pollution
• 00:04:34 The Case Study: A Child's Bedroom Reveals a Shocking Problem
• 00:05:41 The 20X Problem: Why Data Selection Method Matters Enormously
• 00:06:06 The Time Trap: Old Dirty Data Versus Modern Clean Materials
• 00:06:43 The Recommendation: Use the 25th Percentile for Modern Materials
• 00:07:03 The So What: We Might Be Solving Problems That Don't Exist Anymore
• 00:07:27 The New Risks: Recreational Chemicals and Activity-Based Pollution
• 00:08:17 The Living Project: Pandora Needs to Grow and Evolve
• 00:08:38 The Path Forward: From Guessing to Engineering Precision
• 00:08:59 Closing: Transparency and Understanding the Invisible Cloud

This week, we step into the world of moisture in buildings—one of the most overlooked yet critical aspects of indoor air quality and building performance. While we talk about humidity constantly, we rarely stop to break down what we actually mean. What is moisture? Is it a pollutant? And why does it matter so much?

We sit down with David Schurk, owner of HVAC Insight Consultants and a dehumidification specialist with over 40 years of experience in the HVAC industry. David has led system design, application engineering, and field implementation efforts across healthcare, aerospace, industrial, and mission-critical environments. He's an ASHRAE life member and distinguished lecturer, and a course developer and instructor for multiple ASHRAE Learning Institute professional development programs.

Key Topics Discussed:

• Is Moisture a Pollutant? How humidity impacts human comfort, building integrity, and health. Why 30% of the way we regulate our body temperature relies on evaporative cooling—and what happens when high humidity impedes that process.
• The Operating Room Problem: A vivid real-world example of how high humidity in hospital operating rooms causes surgeons to overheat, insist on colder temperatures, which paradoxically increases relative humidity further—creating condensation, discomfort, and potentially dangerous conditions.
• Breaking Down the Terminology: Dry bulb temperature, wet bulb temperature, relative humidity, absolute humidity, vapor pressure, dew point temperature—what do these terms actually mean? How do they interact? And why does relative humidity confuse everyone?
• The Psychrometric Chart: The beautiful, intimidating, and essential tool that maps the relationship between temperature and moisture. How to read it, why it matters, and why it's still relevant in the age of apps and AI.
• Surfaces, Condensation, and Mold: Why moisture risk is one of the few pollutants that can damage the building fabric itself. How dew point, surface temperatures, and adsorptive materials create the conditions for mold growth and structural decay.
• The Case for HVAC-D: Why dehumidification deserves its own prominent place in the HVAC world. How traditional air conditioning treats dehumidification as a byproduct of cooling—and why that doesn't always work.
• Desiccant Dehumidification: How solid and liquid desiccants can achieve moisture removal at levels traditional cold coil systems simply cannot reach—down to negative 100-degree Fahrenheit dew points. The applications in hospitals, pharmaceuticals, semiconductor manufacturing, lithium battery production, and ice rinks.

GUEST:

David Schurk - Owner, HVAC Insight Consultants

https://www.linkedin.com/in/davidschurk/

The Air Quality Matters Podcast in Partnership with

Particles Plus https://particlesplus.com/

Farmwood (https://farmwood.co.uk/) - Eurovent (https://www.eurovent.eu/) - Aico (https://www.aico.co.uk/) - Ultra Protect (https://www.ultra-protect.co.uk/air-quality-matters)

The One Take Podcast in Partnership with

SafeTraces (https://www.safetraces.com/) and Inbiot (https://www.inbiot.es/?utm_campaign=simon&utm_source=airqualitymatters&utm_medium=podcast)

Do check them out in the links and on the Air Quality Matters Website. (https://www.airqualitymatters.net/podcast)

If you haven't checked out the YouTube channel its here (https://www.youtube.com/@airqualitymatters-SimonJones). Do subscribe if you can, lots more content is coming soon.

• 00:00:00 Introduction: The Forgotten Child of Indoor Air Quality
• 00:02:27 Is Moisture a Pollutant? Defining the Problem
• 00:04:11 The Human Impact: Perspiration and Core Temperature
• 00:07:57 The Operating Room Problem: When Humidity Becomes Critical
• 00:14:30 Adding the D to HVAC: Why Dehumidification Deserves Recognition
• 00:28:59 Temperature Fundamentals: Dry Bulb, Sensible Heat, and Radiant Energy
• 00:36:05 Relative Humidity Explained: The Fish Tank Analogy
• 00:42:05 The Relative Humidity Trap: Why It Misleads Us
• 00:53:14 Absolute Humidity and Dew Point: The Real Measures That Matter
• 01:06:32 Wet Bulb Temperature: The Sling Psychrometer Explained
• 01:12:13 The Psychrometric Chart: Your Moisture Roadmap
• 01:18:21 Surfaces and Condensation: When Air Meets Materials
• 01:23:58 The Cold Spot Mold Spot Phenomenon
• 01:26:42 Controlling Moisture: The Thermostat Problem
• 01:30:59 The Efficiency Paradox: High SEER and High Humidity
• 01:32:55 Desiccant Dehumidification: Beyond the 32-Degree Limit
• 01:38:44 Real-World Applications: From Lithium Batteries to Pharmaceuticals
• 01:41:16 The Journey of a Dehumidification Jedi