Air Quality Matters

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 We've been relying on scattered, outdated, inconsistent emission rate data—pulled from 1990s conference papers, paywalled journals, and PDF reports buried in the internet—and wondering why our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

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.

Chapters

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

This week, we dive into a question that goes beyond sensors and science: What actually motivates people to invest in clean air for their homes—and does culture change everything?

The paper is titled Indoor Air Quality: Predicting and Comparing Protective Behaviours in Germany and Portugal, published in Indoor Air, and it's based on survey data from 800 participants split evenly between the two nations. This research uses Protection Motivation Theory to unpack the psychological and cultural drivers behind adopting indoor air quality technologies—things like sensors, air purifiers, and ventilation systems.

Key Insights:

Germany: Autonomy and Family Duty: For German participants, the biggest driver was self-efficacy—the feeling of "I can do this." They need to feel capable, empowered, and in control. There's also a strong link to benevolence caring—particularly protecting close family, especially children. In Germany, you're not buying an air purifier for yourself. You're buying it because you feel a personal responsibility to safeguard your immediate circle.

Portugal: Prove It Works: For Portuguese participants, self-efficacy didn't move the needle. Instead, it was all about response efficacy—does this thing actually work? They're pragmatic consumers. If you tell them it works, you better be able to prove it. Also, people who already had respiratory conditions were much more likely to adopt the tech—health status mattered in Portugal, but not in Germany.

Culture Eats Strategy for Breakfast: You can't use the same messaging in Berlin as you do in Lisbon. In Berlin, you say: "Take control of your home and protect your children." In Lisbon, you say: "This device is proven to reduce particulate matter by 99%."

Fear Doesn't Work: Perceived vulnerability—the feeling that "I am personally at risk of getting sick"—had almost no impact on whether people adopted the technology. None. But perceived severity did. People are motivated when they acknowledge that poor air quality is a serious global or environmental problem—but they aren't motivated by feeling personally weak or susceptible.

The COVID Hangover: The authors suggest this might be a legacy of the pandemic. We became accustomed to taking protective measures—masks, sanitisers, ventilation—not because we were terrified for our own safety every day, but because we recognised the severity of the threat in a broader, almost civic sense.

This is Part Five of a five-part series exploring the psychology and perception of risk around air quality and ventilation.

Indoor Air Quality: Predicting and Comparing Protective Behaviours in Germany and Portugal

https://doi.org/10.1155/2024/3006342

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 Psychology of Air Quality Behavior
00:00:55 The Missing Episode: Germany and Portugal Study Context
00:02:12 The Research Framework: Protection Motivation Theory
00:03:07 Threat and Coping: The Two Mental Processes
00:03:59 The German Mindset: Self-Efficacy and Family Protection
00:04:59 The Portuguese Perspective: Prove It Works
00:06:10 One Size Doesn't Fit All: Cultural Messaging Matters
00:06:31 The Vulnerability Paradox: Fear Doesn't Drive Action
00:07:29 The COVID Legacy: Civic Responsibility Over Personal Fear
00:08:15 The Performance Gap Problem: Why Efficacy Matters
00:08:53 Demographics and Early Adopters: The Youth Factor
00:09:26 Study Limitations and Economic Context
00:09:52 The Key Takeaway: From Education to Empowerment
00:10:46 The Path Forward: Respect, Severity, and Solutions
00:11:17 Closing Thoughts: Understanding the Human Element

This week, we step into one of the most overlooked yet critical areas of air quality and health: the construction site. While we spend so much time talking about indoor air quality during the operational phase of buildings, there's an entire workforce—construction and demolition workers—who spend their careers in environments that are anything but operational. And the risks they face are profound.

We sit down with Angie Brooker, Occupational Health Manager at Multiplex, to explore the layered, dynamic, and often invisible hazards of dust exposure in construction—and what one of the UK's most forward-thinking organisations is doing about it.

Key Topics Discussed:

The Three Categories of Dust: Wood dust, general construction dust, and silica dust—each with different risks, different sources, and different control measures. Why silica, particularly from artificial stone, has become a focal point of concern.

The Complexity of Construction Environments: Why construction sites are uniquely challenging—dynamic spaces, changing materials, multiple trades working on top of each other, high turnover, and the constant tension between program deadlines and health protection.

The Artificial Stone Crisis: How engineered stone (containing up to 90% silica) has caused an epidemic of accelerated silicosis globally—and why Multiplex has banned it on all upcoming projects. The Australia case study, the thousand cases identified, and the proactive public health response.

Hierarchy of Controls in Practice: From elimination and substitution (banning artificial stone) to engineering controls (on-tool extraction, ventilation) to administrative controls (training, awareness, health intervention tours) to PPE (the right mask, worn correctly, every time).

The RPE Challenge: Why respiratory protective equipment is the frontline defence—but also why it's so hard to get right. Facial hair, improper fit, leaving masks hanging like "Christmas decorations," the heat and discomfort, and the cultural resistance to wearing them.

Health Intervention Tours (HITs): How Multiplex walks sites monthly, focusing purely on health hazards, giving positive feedback and room-for-improvement interventions, and using personal dust monitors to make the invisible visible.

The Silica 25 Programme: Three pillars—prevention (banning artificial stone), protection (appropriate RPE, education, awareness), and detection (health surveillance, lung function testing, baseline chest X-rays).

This is a conversation about risk, responsibility, and the long game. It's about recognising that construction workers deserve to retire healthy—and that every day we delay action, we're storing up a public health crisis for the future.

GUEST:

Angie Brooker - Occupational Health Manager, Multiplex

https://www.linkedin.com/in/angie-brooker-abba85123/

https://www.multiplex.global/

https://www.lungsatwork.org.uk/

The Air Quality Matters Podcast in Partnership with

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: Construction Workers and Air Quality Risk
00:01:38 Meet Angela Brooker: Occupational Health in Construction
00:03:59 The Dust Challenge: Categories and Construction Hazards
00:05:44 The Dynamic Construction Environment: A Complex Risk Landscape
00:14:46 The Latent Disease Problem: Why Long-Term Risks Get Ignored
00:20:23 The Liability Gap: Accountability for Chronic Occupational Disease
00:24:50 The Cultural Challenge: From Bravado to Protection
00:36:06 Artificial Stone and Silicosis: The Accelerated Epidemic
00:34:42 The Silica 25 Program: Prevention, Protection, and Detection
00:09:08 Housekeeping and Hidden Exposures: The Resuspension Risk
01:07:57 Respiratory Protection: The Mask Problem
00:31:48 Health Intervention Tours: Making Health Visible on Site
01:19:47 Monitoring and Measurement: Dust Tracking Technology
01:35:14 Health Surveillance: Early Detection and the Medical System
01:31:58 The Smoking Factor: Compounding the Risk
01:27:12 From Nurse to Construction: Angela's Journey
01:39:19 The Path Forward: Getting the Basics Right
01:42:12 Closing: Resources and Support for Construction Workers

This week, we dive into a powerful piece of research that moves beyond surveys and snapshots to ask: What actually motivates people in deprived urban communities to change their indoor air quality behaviours—and how long does it take?

The paper is titled Psychological and Contextual Drivers of Indoor Air Quality Behaviours in a Deprived Urban Community: Evidence from Participatory Research, published in Building and Environment, and it's based on the Well Home Project—an 18-month longitudinal study tracking 110 households in West London.

The Central Question

Unlike most studies that rely on a quick one-off survey, this was participatory research. They didn't just treat residents as test subjects—they worked with them, engaged them, installed sensors in their homes, and followed them over time across four waves of surveys. This is crucial because we know that air pollution disproportionately affects deprived communities—people living in substandard housing, closer to busy roads, with higher rates of pre-existing health conditions. So understanding what drives them to act is absolutely vital if we want to address health inequalities.

But here's the fascinating part: self-efficacy grew over time. At the start of the project, confidence didn't make a huge difference. But as the months went on, people with high self-efficacy became increasingly likely to act. Building that muscle of confidence—that feeling of "I can handle this"—is a process, not a switch.

Key Insights:

The Mold Effect—Visibility is Key: The strongest predictor of behaviour change in the entire study was the presence of visible mold and damp. If people saw mold, they acted. But mold is a late-stage indicator—by the time you see black spots on your wall, you've probably been breathing in damp air for months. We need to make other pollutants visible before the damage is done.

Engagement is a Marathon, Not a Sprint: The longer people were involved in the Well Home Project, the more likely they were to change their behaviour. Sustained engagement is essential—not just a one-off flyer.

What Actually Changed: Residents were most likely to report changes in window opening, cooking, and cleaning. But the only behaviours that showed a statistically significant increase over time were cooking and heating. Why? These might require more knowledge or confidence to adopt—things people learned through participation in the project.

What Didn't Change: Smoking behaviour showed the lowest likelihood of change. Smoking is an addiction—a deeply habitual chemical dependency. Simply telling someone it's bad for indoor air is unlikely to break a nicotine addiction. Some issues require much more specific, targeted health interventions.

The Education Paradox: Individuals with higher levels of education were actually less likely to adopt behavioural changes. The authors speculate this might be a ceiling effect—people with higher education might already be doing some of the right things before the study even started, so they had less room to improve.

Participatory Research Works: By working with communities, the researchers didn't just gather data—they helped catalyze change. The residents who stuck with the project became more and more empowered to control their own environment.

This is Part Four of a five-part series exploring the psychology and perception of risk around air quality and ventilation.

Psychological and Contextual Drivers of Indoor Air Quality Behaviours in a Deprived Urban Community: Evidence from Participatory Research

https://doi.org/10.1016/j.buildenv.2025.114089

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 Psychology of Indoor Air Quality in West London
00:01:16 The Well Home Project: Participatory Research in Action
00:02:14 The Health Belief Model: Understanding What Drives Action
00:03:36 The Key Findings: Severity and Self-Efficacy Win
00:04:41 The Mold Effect: When Visibility Drives Action
00:05:32 Time and Confidence: The Longitudinal Effect
00:06:23 What Changed and What Didn't: Behavior Breakdown
00:07:49 The Education Paradox: Challenging Our Assumptions
00:08:39 The So What: From Scare Tactics to Empowerment
00:10:07 Closing Thoughts: Residents as Active Agents