Source Control Comes First for Good IAQ – GreenBuildingAdvisor

There’s no mystery about how to achieve good indoor air quality (IAQ). But there’s a lot of misinformation and misunderstanding. If you listen to know-nothing influencers, you might think all you need to do is buy whichever magic device they’re promoting. But no one thing by itself can get good IAQ for you. You need a comprehensive approach. And it starts with source control.

The allure of the magic pill

We live in the age of the Internet and social media. With the huge potential for education they hold, we could be living in a golden age. Alas, they also allow misinformation to spread as quickly—or more quickly—as the stuff we know to be true.

I don’t need to say much here because I’ve already covered why you should avoid most electronic air cleaners. The claims made their promoters often are not backed up by real data. In fact, a new study on the interestingly named bipolar ionization method found that they result in “limited pathogen reduction.”

So using these “magic devices” has been described by some experts as doing uncontrolled chemistry experiments with your indoor air. Yes, they may get rid of some of the bad stuff in your indoor air. But they also may create new pollutants.

A comprehensive approach to IAQ

One of the most important maxims of building science is that we look at everything with a systems approach. A house is a system. An air barrier is a system. And achieving good IAQ also requires treating it as a system.

There are many ways to look at improving indoor air quality. In the twenty-plus years I’ve been in the field of building science, I’ve refined my understanding of IAQ a lot. I now promote a seven-step approach to achieving good IAQ:

• Source control
• Airtightness
• Filtration
• Ventilation
• Moisture control
• Pressure balancing
• IAQ monitoring

Go read my article for more detail on the seven steps. Better yet, sign up for my online course on the seven steps to good IAQ. Here’s a little glimpse of what you’ll learn:

Why source control is first

It’s obvious, though, isn’t it? Let’s say you’re in line to get into a popular club. Near you is someone who’s loud and rowdy and obviously drunk. If the guy controlling the door lets him in, it’s going to be harder to remove him when he acts up inside the club. So they just don’t let him in.

It’s the same with source control for good IAQ. Keeping the pollutants out from the start makes it easier to keep the indoor air clean. You may not need as much ventilation. Filters don’t need replacing as often. The IAQ monitors show good results.

We’ve known this for a long time. The message in that quote above (more on that below) is from 1858. A German chemist and hygienist named Max von Pettenkofer made the point clearly that source control is the starting point. Why would you just turn up the ventilation if there’s a dung heap sitting on the living room floor?

About that source control quote

Now, let’s talk about that quote. I like to find out the source of quotes because in these days of Internet and social media nonsense, you just never know. Abe Lincoln said it best:

I couldn’t find any original source for that Pettenkofer quote. (Quote Investigator works for more popular quotes.) The furthest back I could find references to was about 20 years. Since then, it’s been used by a bunch of us in the IAQ community. I first saw it in Joseph Lstiburek’s article “First Deal with the Manure and Then Don’t Suck.” He actually pointed to what is probably the original source of this version of the quote in a footnote in that article.

A few days ago, though, I was thinking about this quote again and asked my friend Steffen Petersen about it. He’s a professor of building science in Denmark and does a lot of work in the field of IAQ. He turned out to be the perfect person to ask. He sent me several Pettenkofer quotes in the original German and also their translations. Here’s the one that most likely morphed into the current version:

Ein Raum, welcher einen verwesenden Misthaufen einschliesst, wird trotz aller Ventilation eine ekelhafte Wohnstätte, ein Herd für schlechte Luft bleiben. Erst wo die Reinlichkeit durch rasche Entfernung oder sorgfaltigen Verschluss luftverderbender Stoffe nichts mehr zu leisten vermag, beginnt das Feld für die Ventilation.

That translates to:

A room that encloses a rotting dung heap will, despite all ventilation, remain a disgusting dwelling place, a breeding ground for bad air. Only when cleanliness, through the rapid removal or careful sealing of air-polluting substances, can no longer achieve anything, does the field for ventilation begin.

Yeah, that’s basically the same thing. As far as Petersen can tell, the current version originated in the 2006 paper by Ole Fanger titled “What Is IAQ?” The image with the quote in the previous section is from that paper. Fanger was also a Danish researcher who did a lot of groundbreaking work in the field of thermal comfort and indoor air quality. And he had a most interesting hair style, as you can see above.

Allison A. Bailes III, PhD is a speaker, writer, building science consultant, and the founder of Energy Vanguard in Decatur, Georgia. He has a doctorate in physics and is the author of a bestselling book on building science. He also writes the Energy Vanguard Blog. For more updates, you can follow Allison on LinkedIn and subscribe to Energy Vanguard’s weekly newsletter and YouTube channel.