air leakage

Energy Efficiency Is Narrowing the Stupid/Hurt Gap

Posted on February 28,2015 by ab3 in air leakage

The gap is narrowing. What gap, you ask? Why, the gap between stupid and hurt, of course. So says Dr. Joe Lstiburek. Allow me to explain.

Sometimes when you do something stupid, it hurts immediately. A toddler touches a hot kettle, for example, and instantly starts crying in pain. That's a learning experience.

If that pain didn't happen until an hour or a day had passed, however, the child would have a tough time learning not to touch hot kettles. Building or remodeling homes is a lot like that.

How Duct Leakage Steals Twice

Posted on February 28,2015 by ab3 in air leakage

Duct leakage is a big deal. It's one of the top three energy wasters in most homes (air leakage and cable TV set-top boxes being the other two). Researchers at Lawrence Berkeley National Lab found that duct systems leak on average about 10% of the supply air they move and 12% of the return air. (Download pdf and also see Dana Dorsett's comment below, #1.) In far more homes than you might suspect, the main culprit is a disconnected duct, as shown in the photo at right, but a typical duct system has a lot of other leaks, too.

Air Leaks From Your Home To Your Attic Need To Be Sealed

Posted on February 28,2015 by Tamasin Sterner in air leak

It’s important to keep attic air out of the house and house air out of the attic. That's why the home performance industry and every above-code building program make it a top priority to fully separate attics from the rest of the building. When the attic isn’t fully air sealed from the living space and the combustion appliance zone, three undesirable scenarios can occur:

Fixing a Leaky Log Home

Posted on February 28,2015 by ScottG in air leak

Early settlers who felled their own trees to build log homes were probably so grateful to be out of the weather they didn't worry about air leaks or cold walls. But when your heating bills are $500 a month, it's a different story altogether. That's the situation facing ADK Homeowner, as he explains in a Q&A post at Green Building Advisor.

Ban the Can

Posted on February 28,2015 by user-1048334 in air leakage

One hates to overstate how problematic recessed lights can be, but… they sure are a pain in the energy-auditor butt. There are worse problems (wet basements), more expensive ones (insulating a complicated roof line), and more frustrating ones (the cross-purposes of energy evaluations and homeowner desires). But few elements of the house combine all three in as tidy a package as recessed light cans.

The History of Peeling Paint, Insulation, and Vapor Barriers

Posted on February 28,2015 by ab3 in air leakage

Back in the 1930s, a rash of paint-peeling showed up across North America. One thing that most of these homes had in common was insulation in the walls. Painters put two and two together and decided that the problem was the insulation. According to building scientist Bill Rose, the painters surmised that the problem was happening because insulation “draws water,” and some refused to paint insulated houses.

Air Leaks in Homes Insulated With Spray Foam

Posted on February 28,2015 by user-1072052 in air barrier

If you’re retrofitting a vintage brick building without an air barrier, don’t count on the spray foam to create a perfect air seal. If you plan to use the spray foam as your air barrier, it's important to test your work before you cover it with drywall so you can seal any air leaks.

Plugging Air Leaks Would Save Billions

Posted on February 28,2015 by ScottG in air leakage

Bringing all U.S. homes to airtightness levels spelled out in the 2012 International Energy Conservation Code would save as much as $33 billion in energy costs annually, according to new research at the Lawrence Berkeley National Laboratory.

Most ‘Houses That Breathe’ Aren’t Very Comfortable

Posted on February 28,2015 by bobswin in air leakage

Recently I heard another comment from a builder who wants to build a house that breathes. I started to reply in an e-mail, and then decided to write a blog instead. What we are doing nowadays in the world of high-performance homes is based on studying hundreds of thousands of houses built in the last half century that have failed — including the majority of superinsulated and passive solar homes built in the 1970s and 1980s in the Northeast — and applying those lessons to building a durable house.

Is the Passivhaus Program Truly Innovative?

Posted on February 28,2015 by ab3 in air leakage

Last month, Joe Lstiburek gave the fifth annual Twitterview from his crawl space. (Peter Troast of Energy Circle has published the transcript of this year’s event.) One of the pearls of wisdom dispensed by Joe was that, “Passivhaus is the only place where real innovation is happening.”

Air Sealing an Attic

Posted on February 28,2015 by user-756436 in air leak

If you want to improve the energy performance of an older house, one of the first steps is to plug your attic air leaks. Although many GBA articles address aspects of attic air sealing, no single article provides an overview of the topic. This article is an attempt to provide that missing overview. I’ll try to explain how you can seal air leaks in a conventional vented, unconditioned attic. If your house has cathedral ceilings — that is, insulated sloped roof assemblies — the air sealing tips in this article don’t apply to your house.

Getting the Biggest Bang for Your Air-Sealing Buck

Posted on February 28,2015 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.

An Interview with Dr. Joseph Lstiburek

Posted on February 28,2015 by ab3 in air leakage

Dr. Joe Lstiburek of Building Science Corporation is on a mission. The issue is residential ventilation. He contends that the residential ventilation standard, ASHRAE 62.2, ventilates at too high a rate, causing problems with humidity in hot or mixed humid climates, comfort and dryness in cold climates, and too much energy use everywhere. The 2013 version makes it worse.

Keeping Cool in a Two-Story House

Posted on February 28,2015 by user-756436 in AC

I was recently a weekend guest at the house of some friends who live in Climate Zone 5 (a zone which includes Nebraska and Massachusetts). Since I have no interest in embarrassing anyone, I won’t mention any names or the home’s precise location. The story, however, is true. The weather was hot. The two-story house was built in the 1980s; it included a single-zone split-system air conditioner that delivered cool air through ductwork to every room in the house.

Energy Upgrades for Beginners

Posted on February 28,2015 by user-756436 in air leak

Owners of older homes often contact GBA and ask, “What can I do to make my home more energy-efficient?” My standard answer goes something like this: “The first step is to hire a certified rater to perform an energy audit of your home. The audit report will include a tailor-made list of retrofit measures to address your home’s specific problems.”

Does Your Air Barrier Work in Both Directions?

Posted on February 28,2015 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 February 28,2015 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.

The Worst House I Ever Audited Was Built in 2008

Posted on February 28,2015 by user-1048334 in air leakage

One thing that sets my teeth on edge as an energy auditor is when folks assume that a new home won’t have energy problems or be inefficient. A friend recently mentioned that weatherization and efficiency work must have a great market with Maine’s old housing stock but would be pointless in new homes. *Commence ripping out hair.*

Green Building for Beginners

Posted on February 28,2015 by user-756436 in air leakage

Green building websites can be confusing. One site might tell you that a green home should include spray foam insulation, a tankless water heater, and a geothermal heating system. After you’ve absorbed this advice, you visit another website, where you learn that spray foam is a dangerous petrochemical, tankless water heaters are overpriced gadgets, and “geothermal” systems aren’t really geothermal.

Is R-Value Dead as a Dodo?

Posted on February 28,2015 by user-1048334 in air leakage

Once upon a time, house insulation meant an extra sweater — and stop your damn complaining. Men were men, women were women, and cats and dogs were cats and dogs, I assume. Houses included features to produce and retain heat, of course — things like double back-plaster walls and central chimneys. But until the 20th century, insulation barely existed in any formal sense.

Register for a free account and join the conversation


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

Syndicate content