Energy Vanguard Blog

A Few of My Favorite Filter Photos

Posted by Allison Bailes on Fri, Oct 14, 2016

There's really no end to the fun stuff you find when looking at furnace & air conditioner filters. Here are a few of my favorites for this Fall Friday.

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Tags: heating & cooling distribution, heating & cooling

Grading an Attempt to Get Ducts Inside Conditioned Space

Posted by Allison Bailes on Wed, Sep 7, 2016

There's a ton of new construction and remodeling going on in Atlanta. On a lot near where I live, a developer tore down the old house and is building two new ones. This weekend, I took the opportunity to check out their progress on the first one and saw the mechanical system roughed in on the first floor. They did some good things in their attempt to keep the air handler and ducts inside conditioned space. They also did some not-so-good things. Let's grade their work.

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Tags: design, heating & cooling distribution, heating & cooling

More on Air Conditioner Sizing Rules of Thumb

Posted by Allison Bailes on Mon, Aug 29, 2016

Air conditioner sizing rules of thumb must die. That's what I wrote in my last article. The most common rule of thumb is to use 500 square feet per ton to determine the size of air conditioner needed. Or 400 or 600 or some other number in that general vicinity. In my article, I showed a graph of air conditioner sizes, given in square feet per ton, for 40 homes that we did load calculations for. The average of the 40 was 1,431 sf/ton. Now, let me say a bit more about that.

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Tags: heating & cooling

Air Conditioner Sizing Rules of Thumb Must Die

Posted by Allison Bailes on Fri, Aug 26, 2016

We design a lot of heating and air conditioning systems at Energy Vanguard. Alexander Bell, who goes by Andy, is our design wizard, and I've been getting involved with the process again lately. When I talk to potential clients, a lot of them tell me their contractor wants to size their air conditioner using a rule of thumb. The rule is usually something like this: Install one ton of air conditioning capacity for every 500 (or 600) square feet of conditioned floor area. How far off are they? Let's take a look.

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Tags: comfort, heating & cooling

Can You Ventilate a Home with Attic Air?

Posted by Allison Bailes on Fri, Aug 5, 2016

I've seen some crazy things done to homes. It's usually someone's attempt to make things better. Sometimes that someone is a homeowner or other occupant. Sometimes it's a contractor. But it always seems to be a solution to a problem that creates other problems. It's just like they say: Our biggest problem is solutions. So what's the problem with this method of ventilating a home?

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Tags: attic, indoor air quality, ventilation, heating & cooling

How Much Insulation Do You Need in a Passive House?

Posted by Allison Bailes on Fri, Jul 15, 2016

Passive house has a reputation for requiring ungodly amounts of insulation. It grew out of the superinsulation movement after all. If you're familiar with any passive house projects, you may be thinking about double-stud walls that are a foot thick or regular walls with 6 to 12 inches of rigid insulation on the outside. But how much insulation can you use and still meet the requirements of the Passive House Institute US (PHIUS)?

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Tags: environment & sustainability, heating & cooling

Daniel Boone's Dew Point Problem

Posted by Allison Bailes on Mon, Jun 27, 2016

In Missouri for the ASHRAE conference, I took some time to visit with my Cajun baby sister the other day. As we were making our way to one of the local wineries outside of St. Louis, we saw a sign for Daniel Boone's house. Now who can resist that? So we took the short detour and spent a few minutes there. (Yes, minutes. There was wine at the wineries after all.) And here's what I saw there.

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Tags: moisture problems, heating & cooling

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

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

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