Air Quality Matters

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)

Chapters

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.

Chapters

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)

Chapters

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.

Chapters

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)

Chapters

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