air leakage

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SonicLQ: Reconnecting Acoustics and Airtightness

Early on in our work on energy-efficient homes, the connection between airtightness and sound centered on airport noise; now a new technology reconnects acoustics and air leakage

Posted on Aug 24 2017 by Peter Yost

Back in the early days of airport noise mitigation programs, there was a pretty strong link between air leakage and sound. A document titled “Tips for Insulating Your Home Against Aircraft Noise” noted, “Sound travels from the exterior to the interior of the home in two ways: through solid structural elements and through the air…. Wherever air can infiltrate a home, sound can as well.”


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Image Credits:

  1. Images #1, #2, #3, and #4: Argonne National Laboratory
  2. Image #5: U.S. Air Force photo by Christopher Ball

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The Difficulty of Updating Georgia’s Energy Code

Trying to get airtightness below 7 ach50 has been a struggle

Posted on May 10 2017 by Allison A. Bailes III, PhD
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Seven years ago, Georgia led the nation. Yep. We were the first state to adopt an energy code that made blower door testing mandatory. All new homes built in the state had to show through performance testing that they had an air leakage rate of less than 7 air changes per hour at 50 Pascals of pressure difference (ach50).


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Image Credits:

  1. Energy Vanguard

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The Energy Conservatory’s New Blower Door Kit

TEC did its homework: its new blower door package is a truly engineered and integrated equipment system

Posted on Apr 27 2017 by Peter Yost

I don’t do blower door work every day, but I do enough of it to appreciate the attention to detail that The Energy Conservatory (TEC) built into its new blower door kit. The kit features a digital pressure and air flow gauge, the DG1000.


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Image Credits:

  1. Images #1, #2, and #3: The Energy Conservatory
  2. Image #4: Peter Yost

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Just Say No to (Swiss) Cheesy Attic Floors

Ceilings with lots of air leaks are an invitation for moisture problems in winter

Posted on Apr 4 2017 by Greg Labbe

As the biting cold of winter hit the Great Lakes area last December, many building owners started to see signs of moisture damage on parts of their walls and ceilings. As we keep indoor temperatures consistent while the outdoor temperature drops, the difference between indoor and outdoor temperatures (the ole’ Delta T, as they call it) becomes greater. This difference pushes indoor air upward; if there are leaks in the ceiling, the air goes up and out and into the cold attic space. That’s the stack effectAlso referred to as the chimney effect, this is one of three primary forces that drives air leakage in buildings. When warm air is in a column (such as a building), its buoyancy pulls colder air in low in buildings as the buoyant air exerts pressure to escape out the top. The pressure of stack effect is proportional to the height of the column of air and the temperature difference between the air in the column and ambient air. Stack effect is much stronger in cold climates during the heating season than in hot climates during the cooling season. — slightly less powerful than the force Darth Vader uses, but equally nefarious.


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Image Credits:

  1. Greg Labbé

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Buildings Don’t Need to Breathe

The word “breathe” just confuses things

Posted on Oct 19 2016 by Allison A. Bailes III, PhD
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Breathe. It's a good thing. We need to breathe to live. Breathing consciously relaxes us. “Breathe” is also the name of a great song by Pink Floyd from the Dark Side of the Moon album.

Breathe, breathe in the air
Don't be afraid to care
Leave but don't leave me
Look around and choose your own ground.

Breathing is required of many life forms. But when it comes to buildings, all this talk of breathing is just confusing.


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Image Credits:

  1. Alexander Bell

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Seven Reasons to Gut Your Aging Bathroom

The real problems with an out-of-date bathroom are beneath the surface

Posted on Aug 24 2016 by Allison A. Bailes III, PhD
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If your home is old enough for a bathroom renovation, you may want to go ahead and completely gut it. I remodeled my bathroom this year and began 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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Image Credits:

  1. All photos: Energy Vanguard

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Three Reasons to Remove Attic Floor Insulation in a Sealed Attic

Attics insulated with spray foam have different characteristics from vented attics

Posted on Aug 10 2016 by Allison A. Bailes III, PhD
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I get asked a lot of questions about spray foam. Do I need an ignition barrier? Should I use open-cell or closed-cell spray foam? Will open-cell spray foam really rot my roof?

But the question I get more than any other on this topic is about whether or not the insulation on the attic floor should be removed when insulating the roof deck in an existing home. As you can tell from the title of this article, my answer is to remove it. Here are my three reasons, in increasing order of importance.


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Image Credits:

  1. Energy Vanguard

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Complex Three-Dimensional Air Flow Networks

That’s what most buildings are or want to be

Posted on Jun 29 2016 by Allison A. Bailes III, PhD
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A lot of discoveries and research work over the past four decades have ledLight-emitting diode. Illumination technology that produces light by running electrical current through a semiconductor diode. LED lamps are much longer lasting and much more energy efficient than incandescent lamps; unlike fluorescent lamps, LED lamps do not contain mercury and can be readily dimmed. to our current understanding of air leakage in buildings. I’ll mention a few here, but I want to focus on one: the MAD AIR paper by John Tooley and Neil Moyer. The full title of the paper was, Mechanical Air Distribution And Interacting Relationships. The first letters of those words spell out MAD AIR.


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Image Credits:

  1. John Tooley and Neil Moyer

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Air Flow Pathways in a Leaky Exterior Wall

I found some interesting air leakage evidence while remodeling my bathroom

Posted on Jun 1 2016 by Allison A. Bailes III, PhD
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This spring 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 falling apart. So when my wife hit the road one Monday in late April to drive across the country, I got out my wrecking bar. The lead photo shows what it looked like at the end of my first full day of demolition.

I opened up the plumbing wall first. Lots of fun stuff, there. But the real fun came when I opened up the exterior wall. The four termite-damaged studs were part of that fun, but something else was even better.


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Image Credits:

  1. Energy Vanguard

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Don’t Let Your Garage Make You Sick

There’s bad stuff in the air in your garage — here’s how to keep it out of the house

Posted on Jan 27 2016 by Allison A. Bailes III, PhD
prime

The odds are high that the indoor air quality is worse in a home with an attached garage than in a home without one. Just take a look at the photo here to see some of the potential sources of pollutants that can get into your home's air. How many do you see?


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Image Credits:

  1. Rubbermaid Products

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