Energy Vanguard Blog

Building Science Word of the Day:  Interstitial

Posted by Allison Bailes on Wed, May 25, 2016

The word "interstitial" comes up occasionally in building science discussions. I think I've heard it a couple of times at conferences just in the past month. That may be because Joe Lstiburek was there. He's the guy who used that word 127 times in his doctoral dissertation, Toward an Understanding and Prediction of Air Flow in Buildings. Does that give you a clue about its meaning?

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Tags: heating & cooling distribution, air leakage

How to Fix a Leaky, Underinsulated Exterior Wall

Posted by Allison Bailes on Mon, May 23, 2016

When I began remodeling my master bathroom last month, I found the exterior wall ripe for some serious improvement. It had a number of problems, and I was excited to find them. It was worse than I imagined in some ways. The photo below shows the wall partially opened up.

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Tags: insulation, air leakage, moisture problems

BPI Pilots New Healthy Homes Evaluator Microcredential

Posted by Allison Bailes on Thu, May 19, 2016

The Building Performance Institute (BPI) recently introduced a new certification called the Healthy Home Evaluator. It's not a standalone credential, though. Anyone looking to add it to their list of credentials must already have one of three other BPI certifications:  Building Analyst, Energy Auditor, or Quality Control Inspector. That's why they're calling it a microcredential.

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Tags: indoor air quality, health & safety

7 Reasons to Gut Your Bathroom When You Remodel

Posted by Allison Bailes on Tue, May 17, 2016

If your home is old enough for a bathroom renovation, you may want to go ahead and completely gut it. I started my bathroom remodel last month with a complete demolition. If I hadn't, a number of problems would have been unavailable for repair...or even undiscovered. Here's what I found when I opened up the walls and ceiling of my 1970 condo in the Atlanta, Georgia area.

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Tags: ventilation, heating & cooling

A Sign of a Good Duct Installer

Posted by Allison Bailes on Mon, May 9, 2016

Matt Risinger is a home builder in Austin. He builds great houses and is also famous for his videos. He has over 26 thousand subscribers on his Youtube channel. I was in Austin last week for the inaugural Humid Climate Conference and had some extra time on Saturday morning. So I got a tour of a few of Matt's projects. I was pleased to see that pile of materials below at one of those homes. Can you tell why?

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Tags: heating & cooling distribution

Questions on Building a Passive House in a Humid Climate

Posted by Allison Bailes on Fri, May 6, 2016

It’s hard enough to control humidity in humid climate homes when they’re just built to code these days. The air conditioner traditionally has handled the dehumidification, but increasing requirements for insulation and air tightness affect the sensible load more than the latent. Then, when you go all the way to superinsulated houses like Passive House, you’ve got almost no sensible load. But you also have limits on energy use to get the certification.

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Tags: energy efficiency programs

The Timeless Nature of Building Science Principles

Posted by Allison Bailes on Thu, May 5, 2016

Can an article be out of date just because it's from 1989? That's not only three decades old, but it's also from the last century. Heck, it's even from the last millennium! What about more recent stuff? Is it better because it's newer? Well, maybe. But someone recently questioned the suitability of articles I had given as a reading assignment. Some were from 2010, they said. 

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Tags: education

The Water Efficiency Rating Score (WERS) Launches

Posted by Allison Bailes on Wed, May 4, 2016

The Green Builder Coalition has been working hard on their Water Efficiency Rating Score — the WERS — for homes. The inaugural WERS training happened in Santa Fe, New Mexico in March. I was in that class, and I learned a lot. Now the program, which has been in development for the past couple of years, is ready for prime time.

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Tags: water, environment & sustainability

An Air Barrier Is NOT a Product

Posted by Allison Bailes on Tue, May 3, 2016

Professor John Straube is one of the smartest guys in building science. On top of that, I think he's the best presenter in the field. At the Air Barrier Association conference in Baltimore, he gave one of the best building science talks I've heard. Of the things he said, this statement really stood out:

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Tags: air leakage

Design Flaws That Can Rot Your House

Posted by Allison Bailes on Mon, May 2, 2016

Most of the moisture management problems I've written about here are ones that occur because of poor installation. When builders don't integrate window flashing with the drainage plane, for example, water can find its way in and rot out the window framing. Sometimes, however, architects make it harder on builders. When they design building features that make it hard to drain the rain, failure is more likely. Let's look at a few design flaws of this type.

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Tags: design, moisture problems