Energy Vanguard Blog

4 Types of R-Value

Posted by Allison Bailes on Fri, Apr 29, 2016

We talk about R-value all the time. "I've got an R-19 wall," or "Code requires R-38 in my ceiling." But what are those numbers? As it turns out, when we talk about R-value we usually give the R-value of the insulation. That's the case with both of those statements above. But what's the real R-value of the wall or the ceiling? Insulation makes up only a part of each. There's also wood and drywall and sheathing and cladding and...

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Tags: insulation, heating & cooling

Air Flow Pathways in a Leaky Bathroom Wall

Posted by Allison Bailes on Tue, Apr 26, 2016

Last week I spent a lot of hours in my bathroom. I was sick. Really. I was sick and tired of having an outdated bathroom that was beginning to fall apart. So when my wife hit the road last Monday to drive across the country, I got out my wrecking bar. Here's what it looked like last Tuesday afternoon.

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Tags: air leakage, indoor air quality, moisture problems

2 Home Performance Music Videos You Just Gotta See

Posted by Allison Bailes on Fri, Apr 22, 2016

Today I have a special treat for you. These two music videos give a whole new meaning to the term "home performance." The first one came out in 2009, just as the ARRA program was about to crank up. The second one is from 1988, nearly two decades before Youtube. They're both classics. (I would include James Brown's blower door video, too, but I've already put it in another article.)

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Tags: fun

Foam Insulation and Global Warming, Part 3

Posted by Allison Bailes on Wed, Apr 20, 2016

Well, I really stirred things up with my last article on insulation and global warming. My intention was to explain why Alex Wilson's results could be doing a disservice to the green building community. In the end, I was rightly accused of have done a disservice myself. So, here goes with part three of my take on the global warming impact of insulation. Let's see if I can get closer to the truth this time.

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Tags: insulation, environment & sustainability

Adventures in Hotel Bathroom Ventilation

Posted by Allison Bailes on Mon, Apr 18, 2016

I always look at the bathroom ventilation when I'm staying in hotels. Last month I was at the Air Barrier Association conference in Baltimore and took the photo below. Can you tell anything about what might be happening by looking at it? I didn't do a thorough investigation, but here's what I see.

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Tags: indoor air quality, moisture problems, ventilation

The Humid Climate Conference Is Gonna Rock!

Posted by Allison Bailes on Fri, Apr 8, 2016

The first ever Humid Climate Conference is being held next month in Austin, Texas. Kristof Irwin and I have been kicking this idea around for a couple of years now, and he's making it happen. It's a one-day event on 6 May with some great speakers. It's being hosted by the Austin chapter of the Passive House Alliance US (PHAUS) in partnership with the Passive House Institute US (PHIUS) and PHAUS. In other words, the emphasis is on high performance buildings.

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Tags: moisture problems, heating & cooling

Does Your Water Resistive Barrier Really Resist Water?

Posted by Allison Bailes on Wed, Apr 6, 2016

A water resistive barrier (WRB) provides protection against water damage for water that gets behind the cladding of a building. But what if it doesn't really resist water? I've written a lot about installation problems that can lead to compromised water resistance. (See the article I wrote last week, for example.) But other factors can make them leaky, too. Too much exposure to ultraviolet (UV) light is one of them.

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Tags: moisture problems

A Vivid Demonstration of the Benefit of Exterior Insulation

Posted by Allison Bailes on Mon, Apr 4, 2016

A couple of weeks ago I caught up with Anthony Cox at the Air Barrier Association conference in Baltimore. You may know Anthony as the inventor of the House of Pressure, a great model for demonstrating backdrafting, zonal pressure differences, and other building pressure phenomena. Well, now he's got a new toy and he brought it to Baltimore for the conference.

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Tags: insulation, moisture problems

The Misleading "Science" Behind Heat and Insulation

Posted by Allison Bailes on Fri, Apr 1, 2016

Conventional thinking says putting insulation in a building prevents heat loss in winter and heat gain in summer. This comes from the 19th century physicists who invented the laws of thermodynamics. The second law of thermodynamics in particular gives us the impression that insulation can be a good thing. It says, in simplified terms, that heat flows from warmer areas to cooler areas. But it's always good to question conventional thinking, so I've been looking into the history of heat.

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Tags: heating & cooling

Down and Out Is the Rule for Draining the Rain

Posted by Allison Bailes on Wed, Mar 30, 2016

I'm seeing more and more projects with house wrap where the installers do the window details properly. Or at least better. The photo below shows the house wrap lapping over the flashing tape at the top of the window. Often it's the reverse. And the house wrap in those cases is not only beneath the flashing tape, but it's also beneath the window's nailing fin.

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Tags: windows, moisture problems