Energy Vanguard Blog

A Sticky Psychrometric Situation: Wet Bulb Temperature

Posted by Allison Bailes on Tue, Jul 7, 2015

Wet bulb temperature tells you how easy it is for water to evaporate. Sounds simple enough, right? Today I'll give you a couple of examples to see how well you really understand that simple statement. First, early last month my friend Mike MacFarland texted me about the day he wore his wet bulb shirt on a mountain bike ride. Here's what he said:

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Tags: comfort, environment & sustainability, moisture problems, health & safety

17 Reasons I Love Working with Buildings

Posted by Allison Bailes on Mon, Jun 29, 2015

Yesterday I had lunch with Robert Bean and Eric Griffin at the ASHRAE conference here in Atlanta. As we talked about how we got into the field of building science, I began thinking of the reasons I love doing what I do. My background is physics, and I really enjoyed teaching it when I was in academia, but I didn't really fit in there. When I discovered building science (and later blogging), I finally found my niche. Here's why:

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Tags: fun, design, education, business, comfort, indoor air quality, environment & sustainability, big picture, creativity, health & safety, blogging

A Beautiful Solar Home in Utah Nears Net Zero Energy Use

Posted by Allison Bailes on Wed, Mar 18, 2015

I'm writing this on St. Patrick's Day so let me tell you a wee bit about the O'Mearas. Kevin and Svetlana O'Meara live in a beautiful home in Utah that's oh-so-close to being a net zero energy home. After I wrote about how home building is like skiing two years ago, Kevin invited me out to see their home and this year I managed to do so. My wife and I visited them for two days last week and Kevin told me all about the house, including his one major regret.

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Tags: ENERGY STAR, design, heating & cooling distribution, insulation, air leakage, energy code, energy conservation, comfort, windows, environment & sustainability, solar energy, water heating, ventilation, heating & cooling, green building

A Net Zero Energy Home in a Beautiful Green Community

Posted by Allison Bailes on Tue, Nov 26, 2013

I spoke at Serenbe, a beautiful green community southwest of Atlanta, this weekend and got a chance to visit a net zero energy home while there. Built by Luis Imery, one of the home energy raters we're a HERS provider for, the home has garnered quite a bit of recognition. In fact, they recently picked up a pretty big award from Southface.

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Tags: ENERGY STAR, HVAC, building enclosure, heating & cooling distribution, insulation, air leakage, energy code, comfort, spray foam, indoor air quality, solar energy, ventilation

Fixing an Old House? Follow Einstein's Advice

Posted by Allison Bailes on Mon, Nov 4, 2013

I get a lot of questions from people asking how they should go about fixing their homes. Sometimes it's specific (What's the best way to insulate my kneewalls?), and sometimes it's a hands up in the air, With all these problems, where do I start?  I'll focus on the latter today and let Albert Einstein provide the guidance you need.

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Tags: HVAC, building enclosure, crawl space, air leakage, attic, comfort, windows, indoor air quality, diagnostic/performance testing, solar energy, water heating, health & safety, ventilation

This Little Ventilation Mistake Can Lead to Comfort Problems

Posted by Allison Bailes on Wed, Oct 9, 2013

If you're designing a ventilation system, first you have to determine how much air the house needs. You can use ASHRAE 62.2 or the new BSC-01 for that task. Then you have to decide what type of ventilation system to use: positive pressure, negative pressure, or balanced. In many green homes, the balanced system is becoming a popular choice. I've seen some installations lately, though, that are missing a key component.

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Tags: HVAC, design, heating & cooling distribution, comfort, ventilation

Why Do So Many Expensive Homes Get Walmart-Class HVAC Systems?

Posted by Allison Bailes on Tue, Oct 8, 2013

The fellow standing in the home he's having built is proud. It's his dream home in Brookline, Massachusetts after all. The Wall Street Journal last week published an article about affluent home buyers getting their own jumbo construction loans to do just as Mr. Deshpande has done. Usually, they hire a home builder to build the home, but if you look at that photo, you'll see a mistake that's common even in million dollar homes.

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Tags: HVAC, design, heating & cooling distribution, comfort, spray foam

Advice to Architects: Draw Those Attic Kneewall Sections Right

Posted by Allison Bailes on Mon, Oct 7, 2013

We're working on a project, so we got a set of plans to get started. It includes the attic kneewall and vaulted ceiling section you see below.This is typical of plans that architects draw, and builders build houses this way all the time. Unfortunately, it contains several errors. Can you spot them?

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Tags: design, building enclosure, insulation, attic, comfort, spray foam

A Surprisingly Common Cause for High Energy Bills

Posted by Allison Bailes on Fri, Sep 27, 2013

She lives in a small, simple house in southern Mississippi. It's only 1700 square feet. Why then, she wondered, were her summer electricity bills running more than $600? She didn't have anything that could be a big energy hog, like a swimming pool, and she didn't do stupid things like leave all the doors and windows open while she ran the air conditioner. What could it be?

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Tags: comfort, heating & cooling

Don't Try This Recycling Trick at Home!

Posted by Allison Bailes on Thu, Sep 5, 2013

I confess that, back in the '80s, I might have done the same thing this couple did. I remember reading Mother Earth News and Practical Homeowner magazine articles about folks who collected discarded materials to use in their existing homes or to build a new one. Take that man in Colorado, for example, who had a materials stash big enough to build a whole, nice-sized house for only $5000. That was cool! Since then, however, I've learned why I would have regretted building a house resembling what you see below.

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Tags: HVAC, design, comfort, windows, environment & sustainability, moisture problems