blower door

A Blower Door Is the Hydraulic Jack of Building Science

Posted on March 02,2015 by ab3 in air pressure

Remember the first time you ran a blower door? OK, maybe that's not the best way to get where I'm going because most first-timers turn the pressure up like they're practicing tai chi on Jupiter. After you've done a few tests, though, you learn to crank it up to 50 Pascals of pressure difference in just a few seconds. And that's where you may have discovered the mystery that Blaise Pascal solved nearly four centuries ago when he invented the hydraulic press.

Getting the Biggest Bang for Your Air-Sealing Buck

Posted on March 02,2015 by user-756436 in air leakage

Most new homes are leaky. In the typical new home, significant volumes of air enter through cracks near the basement rim joists and exit through ceiling holes on the building’s top floor. These air leaks waste tremendous amount of energy.

ACI: The Conference Formerly Known as Affordable Comfort

Posted on March 02,2015 by CarlSeville in ACI

The 2013 ACI National Home Performance Conference, called Affordable Comfort until a few years back when the conference was renamed ACI, recently took place in Denver, Colorado. This year, the conference came complete with about six inches of snow in May — quite a shock for a transplanted Southerner.

Does Your Air Barrier Work in Both Directions?

Posted on March 02,2015 by ab3 in air leakage

Do you want a good air barrier on your house? Of course you do. No one who knows anything at all about building science believes that old myth that a house needs to breathe. We want airtight houses, but then we want mechanical ventilation to bring in fresh air from outside (well, at least as fresh as you can get from your outside).

Meet the Tightest House in the World

Posted on March 02,2015 by ScottG in ach50

A Dillingham, Alaska, couple has claimed a world record for airtightness in a 600-sq. ft. home with 28-in. thick walls and a ceiling rated at R-140. According to the World Record Academy, a blower-door test measured 0.05 air changes per hour at 50 pascals of pressure (ACH50), less than 10% of the very rigorous Passivhaus air-tightness standard of 0.60 ACH50.

A Good Time for Energy Audits and Weatherization

Posted on March 02,2015 by AlexWilson in blower door

Wait a second. Spring has barely sprung, and you’re saying we need to start thinking about energy audits already? What’s up with that? There are several reasons why now is a good time not only to focus on energy auditing and weatherization work — not only for your clients, but also for your own home.

The Tail-Wagging Labradors of RESNET

Posted on March 02,2015 by ab3 in ACCA

Labradors? James Brown? What do either of those have to do with the RESNET conference?! Be patient, my friend. All will be revealed shortly. The 2013 conference sponsored by the Residential Energy Services Network (RESNET) in Orlando a few weeks ago was fantastic. It and Building Science Summer Camp are my two favorite events of the year, and this year RESNET was better than ever.

Air Leakage at Electrical Switches and Outlets

Posted on March 02,2015 by ab3 in ADA

One thing that invariably surprises people when I walk them through a house during their first blower-door test is how much air leaks in through the electrical switches and receptacles. On a recent Friday, we went out to do the last home energy rating in our latest HERS rater class, and we got to see something even better. But first, let's talk about that air leakage. We have a number of surprises waiting.

Blower Doors Have Become Essential

Posted on March 02,2015 by user-1048334 in air barrier

Blower doors are spoken of in reverential tones in energy circles. Or at least they were a few years back. Now you can’t throw a manometer without hitting a contractor setting up a blower door. Which is a very, very good thing. With the incorporation of air leakage standards into various housing codes, blower doors are becoming essential. In fact, I tell customers that a simple shorthand for whether your insulation contractors grok building science is whether they own/use/understand blower doors.

What’s a Blower Door Good For?

Posted on March 02,2015 by ab3 in ach50

In last week's blog, I suggested that talking about infiltration rates in terms of air changes per hour isn’t an accurate way to portray air leakage. The problem is that you’re dividing by volume but the leaks happen at the surface. I don’t think ACH50 is going away anytime soon, and I use it myself because everyone else does, even though it’s biased toward larger houses.

Air Leaks Happen at the Surface, Not in the Volume

Posted on March 02,2015 by ab3 in ach50

During the Westford Symposium on Building Science in 2010,* I was watching the tweets from the people who were there. At one point, I saw this one: “@EFL_Guy: ‘Air leaks through surfaces, not volume’ Joe Lstiburek.” I'd been meaning to blog about this issue for a while, so I wrote an article about it. Now, a couple of years later, it's time for a little update.

Essential Energy-Audit Equipment

Posted on March 02,2015 by user-1048334 in blower door

I thought I’d put together a list of all of the tools and equipment I use during an energy audit. Not all of these tools are used during every audit, and some aren’t essential to investigating the house. I’ve separated the lists into two categories: essential items and useful items.

Test Driving the New Brattleboro Food Co-op Building

Posted on March 02,2015 by AlexWilson in air leakage

The new Brattleboro Food Co-op building with affordable housing on the top two floors is nearly completed, and we’ll be shopping there in just a week or two. So, how did the building turn out? Were the goals achieved? Are the mechanical systems going to work as intended? How effectively was the building envelope constructed?

How Much Air Leakage in Your Home Is Too Much?

Posted on March 02,2015 by ab3 in air leakage

Whether you want to build a new home or fix an old one, the way to ensure that you get the best performance is to do the building envelope right. That means installing the right amount of insulation and installing it well, and it means having an air barrier with minimal leakage. But how do you know when you've done enough air sealing? How tight is tight enough?

A Net-Zero-Energy Home in Rural Tennessee

Posted on March 02,2015 by ab3 in blower door

On my thousand-mile quality assurance road trip last week, I visited a house that was designed to produce more energy than it uses, making it a net zero energy home. You can take any house all the way to net zero just by giving it enough on-site power production (photovoltaics, wind, hydropower...), but that's not the most effective way to achieve the goal of net zero energy use. First, you want to make the house really efficient, and that's what these folks did.

Is the Pretty Good House the Next Big Thing?

Posted on March 02,2015 by ab3 in blower door

I love the Pretty Good House concept! The folks up in Maine who've been developing this idea in their monthly green building discussion group (Steve's Garage) have struck a chord with a lot of us who design, build, or verify green homes. The growing complexity and expense of green building and energy programs has led to growing frustration.

The Case of the Mystery Gas Leak

Posted on March 02,2015 by ScottG in air tightness

What began as an attempt to track down the source of air leaks in his one-year-old home has [no-glossary]led[/no-glossary] Kevin Hilton to a deeper mystery — a natural gas odor that is apparent only when energy auditors are running a blower-door test. As Hilton explains in a Q&A post at GreenBuildingAdvisor, the source of the gas leak has been impossible to track down so far.

Top 10 Air Leaks in Existing Homes – Part 2

Posted on March 02,2015 by Tristan Roberts in air barrier

From an energy-efficiency standpoint, the trouble with owning an old home is that you’re stuck with whatever bad decisions the previous owners made, and historical trends also tend to work against you. The trouble with building a new home is that you are the one that is going to make the bad decisions. The best opportunity to make important decisions that will deliver energy efficiency for the life of the home is during design. There is rapid diminution of these opportunities during construction and then during use of the home.

An Energy-Auditing Class in Montana

Posted on March 02,2015 by pGS3rxsTa6 in auditing class

When I arrive for the five-day energy-auditing course at the Pure Energy Center in eastern Montana, I see instructor A. Tamasin Sterner outside the main house, clapping her hands and doing a little dance. If you know Tamasin, a veteran energy auditor who famously counseled President Obama on the need for weatherization programs, you expect this show of exuberance.

How to Get Good Blower-Door Results

Posted on March 02,2015 by user-826746 in air leakage

Our development company has been working with several builders, including our own parent company, to determine the factors that affect our blower-door test results. The following list includes things we have learned to do, and things we have learned not to do, to achieve an optimal blower door test result. (We aim to achieve the Passivhaus standard of 0.6 ach50.)

Register for a free account and join the conversation


Get a free account and join the conversation!
Become a GBA PRO!

Syndicate content