The most recent blogs at Green Building Advisor

Two Single-Family Passivhaus Projects in Maine

Posted on July 18, 2013 by jesper kruse in Guest Blogs

In 2006 my wife, my two small kids and I packed our stuff and moved from Maine to my native Denmark for a year. Before leaving for Denmark I was thinking about transitioning from building traditional 2x6 stick-built homes to building green (whatever that might be). While living in Denmark I heard about the PassivhausA residential building construction standard requiring very low levels of air leakage, very high levels of insulation, and windows with a very low U-factor. Developed in the early 1990s by Bo Adamson and Wolfgang Feist, the standard is now promoted by the Passivhaus Institut in Darmstadt, Germany. To meet the standard, a home must have an infiltration rate no greater than 0.60 AC/H @ 50 pascals, a maximum annual heating energy use of 15 kWh per square meter (4,755 Btu per square foot), a maximum annual cooling energy use of 15 kWh per square meter (1.39 kWh per square foot), and maximum source energy use for all purposes of 120 kWh per square meter (11.1 kWh per square foot). The standard recommends, but does not require, a maximum design heating load of 10 W per square meter and windows with a maximum U-factor of 0.14. The Passivhaus standard was developed for buildings in central and northern Europe; efforts are underway to clarify the best techniques to achieve the standard for buildings in hot climates. standard, and realized that this is the holy grail of green construction (at least if you think green is mostly about energy, which in my mind is where it’s at).

EPA Warns Against Unapproved Refrigerants in Air Conditioners

Posted on July 17, 2013 by Allison A. Bailes III, PhD in Building Science

"A New Zealand technician got fire balled in the face," a member of the forum stated bluntly. He was referring to a case in New Zealand where an HVAC tech got burned when he thought he was working on a system with R-22 refregerant, which is not flammable, but which instead was filled with propane, which is flammable.

Ceiling Fans Are Evil

Posted on July 16, 2013 by Carl Seville in Green Building Curmudgeon

I can’t count the number of times I have walked past a neighbor’s home and seen the porch ceiling fans running with no one there to appreciate them. All the fans are doing is wasting electricity and contributing a little heat to the outdoor air. I am tempted (although I have never acted on the impulse) to pull the chains and turn the fans off or leave the neighbors a note.

Putting the Duct Back in Ductless

Posted on July 15, 2013 by Scott Gibson in Q&A Spotlight

Ductless minisplits have a lot going for them. These high-performance air-source heat pumps operate efficiently at much lower outdoor temperatures than standard heat pumps, and they don't suffer the same energy losses due to leaky ducts. A tight, well-insulated house may need only one or two wall-mounted heads to maintain comfort indoor conditions, in summer and winter.

It's the "wall-mounted" part, however, that not everyone warms up to.

Garage Door Openers Are Always On

Posted on July 12, 2013 by Martin Holladay in Musings of an Energy Nerd

If your home has a garage, there is a good chance that you have an automatic garage door opener. Because these electrical appliances operate for only a few minutes per day, they don’t use much electricity to open and close your garage door. But there’s a catch: most garage door openers use three to five times more energy during the 1,437 minutes per day when they are “off” than they do during the 3 minutes per day when they are on.

Sometimes, It’s Cheaper to Install PV Than More Insulation

Posted on July 11, 2013 by Alex Wilson in Energy Solutions

There’s an age-old question of how much insulation to install in our homes. Conventional wisdom says to add more until the “payback” for the added insulation isn’t worth it — until the energy savings that will result from the insulation doesn’t pay back the cost of that insulation quickly enough.

Energy and environmental consultant Andy Shapiro, of Energy Balance, Inc. in Montpelier, suggests a different approach: basing that decision on the cost of a solar electric system.

Resistance May NOT Be Futile in the Residential Ventilation Wars

Posted on July 10, 2013 by Allison A. Bailes III, PhD in Building Science

“ASHRAE 62 is the only national consensus standard document there is. Follow 62.2. Resistance is futile.” So said Dr. Max Sherman last summer in a presentation for the Building America Technical Update meeting. (Download pdf official report here.) That statement about resistance being futile isn’t generally a line you want pinned to you if you’re trying to win hearts and minds, but I asked Sherman about it.

Disseminating Building Science Knowledge

Posted on July 9, 2013 by Vera Novak in Guest Blogs

Each time I meet with the “choir” of sustainable builders or building scientists, I gain more knowledge and solidify the existing knowledge I have. The only problem is that the members of this choir are often fairly constant, and the tune we sing is the same: “How do we teach our song to the masses?”

This isn’t a topic that should remain confined among a select few; we need energy savings, resource regeneration, and sustainability in all manners — now!

Get Your Own Healthy Green Home for Only $15 Million

Posted on July 8, 2013 by Carl Seville in Green Building Curmudgeon

An article in the New York Times recently featured a company specializing in super-high-end healthy homes. The company, Delos Living, has created something it calls the WELL Building Standard — a standard designed to improve occupants' health through a series of what the company maintains are unique features and technologies.

Keeping Cool in a Two-Story House

Posted on July 5, 2013 by Martin Holladay in Musings of an Energy Nerd

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.

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