Heating or Cooling – Which Costs You More?
I love to ask people here in Atlanta and other parts of the Southeast if they think it costs them more to heat their home or to cool their home. The answer I get is almost always the same -…
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What’s the Payback on Home Energy Efficiency?
Here's Why That's the Wrong Question! If you're investing in energy efficiency improvements for your existing home or buying a new high performance home, calculating the simple payback for your investment is at best incomplete and at worst, completely irrelevant.…
Rats to You, Daniel Bernoulli! – Understanding Air Pressure
The most interesting topic we covered in my first semester of college physics was fluid dynamics. I found it fascinating, especially Bernoulli's principle. It wasn't until I left academia and entered the field of building science, however, that I really…
An Incomplete Building Envelope Doesn’t Work
I visited a new house earlier this year that had a basement wall that looked fine* at first glance. At left you see this wall, with its 2"x4" framing and fiberglass batt insulation. That wall you're looking at, though, has…
The Foil-Faced Bubble Wrap Sham – Understanding Radiant Barriers
When I wrote about my trip to the Southeast Building Conference (SEBC) in July, I mentioned how some products on display there really annoyed me because they're either bad to the bone or overhyped. The main one in the latter…
Don’t Forget the Science in Building Science
This week I read and commented on Avoiding the Global Warming Impact of Insulation by Alex Wilson" target="_blank">Avoiding the Global Warming Impact of Insulation by Alex Wilson over at Green Building Advisor. I'd avoided the article for a while since…
It’s the Hole – Understanding What a Blower Door Is for
There's been a lively discussion going on in the RESNET/BPI group on LinkedIn. I posted my article about how infiltration occurs at the surface, not in the volume, and it's generated some good comments. In that article, I said we…
Infiltration Occurs at the Surface, Not in the Volume
At the gym the other night, I was thinking about a tweet I'd seen the day before: "@EFL_Guy 'Air leaks through surfaces not volume" Joe Lstiburek.'" I'd been meaning to blog about this for a while, so, during my workout,…
I Don’t Need No Stinkin’ Building Science Summer Camp!
I'm not at Building Science Summer Camp this week. In case you haven't heard, the event, formally called the Westford Symposium on Building Science, is by invitation only. And I didn't get an invitation. Not that I would have gone…
Turn Off That Dehumidifier!
I was in a crawl space in Atlanta yesterday putting a new home energy rater through his field test and found that this home has a dehumidifier down below. Not surprisingly, it ran continuously the whole time I was there. …