Ductless Mini-Splits Can Get Nasty Inside
Have you ever used a flashlight to look up into the part of a ductless mini-split where the air blows out? I should have done that a lot sooner than I did. It turns out these heat pumps can get…
indoor air quality
A Burnt Grilled Cheese and the Collapse of Indoor Air Quality
I burned a grilled cheese sandwich recently. I tried to bury the evidence by throwing it in the trash and forgetting about it, but my dear, sweet wife fished it out. "You need to tell the world about this," she…
A Weekend Zehnder ERV Installation Blitz
You may recall that in 2021 Zehnder America gave me one of their premium energy recovery ventilators (ERV) with all the components I needed to get it up and running in my house. It's taken longer than I wanted to…
What Is PM2.5?
You can't see them. You can't smell a lot of them. In fact, they're hard to access with any of your senses. But that doesn't mean your body won't respond to those tiny airborne particles that make up what scientists…
The Problem With Too Many Basement Walls
Ever been in a basement that smelled musty? Maybe the better question to ask would be if you've ever been in a basement that didn't have that smell. Far too many basements do. There could be any number of reasons…
Radon Reduction From Basement Sealing – Preliminary
Shortly after my wife and I bought our 1961 home in 2019, I discovered a serious problem in the basement. Where I could see it, the slab was cracked all along the edge of the exterior walls (photo above). I…
Don’t Vent Bath Fans to the Attic!
Bathrooms need some way of exhausting air. Mostly it's to keep the humidity down, but, depending on who lives in the house, the bathroom also can be a source of a lot of volatile organic compounds (VOCs). Not all homes…
Fireplace Building Science – Pros and Cons
Ah, who can resist the ambiance of a crackling fire! Well, it turns out quite a few can. Whether to use a fireplace or not is a controversial topic in building science. The main problem is that a typical wood-burning…
Weatherizing an Old House: An MLK Day Service Project
A lot of volunteers gathered in Decatur, Georgia this past weekend for the annual Martin Luther King Jr. Service Project. They worked at a number of sites doing all kinds things to improve the homes of low-income senior citizens. The…
A Vivid Look at the Effects of Air Pollution
This week I saw a photo that will haunt me for the rest of my life. It's one thing to know something. It's another to see it. I've been writing about indoor air quality and the health effects of indoor…