The most recent blogs at Green Building Advisor

The ‘Low-Hanging Fruit’ Fallacy

Posted on October 9, 2014 by Nate Adams in Guest Blogs

First, a definition. The phrase “energy efficiency programs” (or just “programs”) refers to any utility-funded or state-funded program that offers homeowners a rebate, incentive, or inexpensive financing to make energy efficiency upgrades in their homes.

Using Server Farms to Heat Buildings

Posted on October 8, 2014 by Allison A. Bailes III, PhD, GBA Advisor in Building Science

Last week in my ASHRAE newsletter, I saw an interesting story about a cool thing that Amazon.com is planning to do with heat. Amazon, in case you didn't know, is a heavy user of computers. Not only do their run their online store but they also have a popular cloud computing service. Computers turn electricity into kitten videos, celebrity tweets, and waste heat.

Part 5 of GBA’s Passivhaus Video Series

Posted on October 7, 2014 by GBA Team in Green Building Blog

At 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. job site in Falmouth, Massachusetts, architect Steve Baczek specified triple-glazed Makrowin windows from Slovakia. The windows were installed as "in-betweenies," and the perimeter of each window was sealed with Siga Wigluv tape.

To make sure that the installations were watertight, each window was tested with a garden hose equipped with a spray nozzle after it was installed.

Don’t Be an Air Hole! — Part 2

Posted on October 7, 2014 by Christopher Briley in Green Architects' Lounge

Phil and I have freshened up our drinks and now we're ready to tackle Items 8 through 15. Be sure to go back to Part 1 to listen to Items 1 through 7.

Here's a link to the PowerPoint presentation that inspired this podcast: Sprout Follies at NESEA.

Passivhaus Design in Minnesota

Posted on October 6, 2014 by Scott Gibson in Q&A Spotlight

As net-zero energyProducing as much energy on an annual basis as one consumes on site, usually with renewable energy sources such as photovoltaics or small-scale wind turbines. and 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.-certified houses become more commonplace, it's not at all unusual to hear of exterior walls rated at R-40 or R-50. But that's not going to be nearly good enough for Tom Schmidt, who's building a 3,800-square-foot house in Minnesota.

R-80 is more like it, and the walls need to be "cost-effective" as well as not too thick.

Wolfgang Feist Defends Thick Insulation

Posted on October 3, 2014 by Martin Holladay, GBA Advisor in Musings of an Energy Nerd

Dr. Wolfgang Feist is the founder of the Passivhaus Institut in Darmstadt, Germany. On September 22, 2014, after Feist gave an address at a Passive House conference in Portland, Maine, he agreed to be interviewed. (For links to my two previous interviews with Dr. Feist, see the “Related Articles” sidebar below.)

Q. What will it take for a higher percentage of new buildings to be built to the Passivhaus standard?

Designing a ‘One Knob’ Incentive Program

Posted on October 2, 2014 by Nate Adams in Guest Blogs

Author's note: This series is aimed at the home performance industry. My company values transparency, so we put it in the public sphere for homeowners to see and understand our thinking.

Rethinking Recessed Lighting

Posted on October 2, 2014 by Debra Silber in Green Building Blog

Recessed can lights have gained a reputation as the go-to fixture for inexpensive downlighting. But they have their drawbacks. When placed in an upper ceiling and not sealed and insulated, they can bleed energy. When improperly insulated, they can present a fire hazard.

The Difference Between Efficiency and Efficacy

Posted on October 1, 2014 by Allison A. Bailes III, PhD, GBA Advisor in Building Science

When I was doing research for an article on ceiling fans a while back, I noticed that fans don't have energy efficiency ratings; they have efficacy ratings.

There's certainly confusion about the terminology among different sources, but since light bulbs are also described by their efficacy, I started wondering about the term. I'd just accepted it before, with a vague understanding that there was something different about how efficacy was defined. Now I know why.

Think Home Buyers Won’t Pay Extra for Energy Efficiency?

Posted on September 30, 2014 by Nick Sisler in Guest Blogs

According to a national survey of 116 single-family home builders, developers, and remodelers performed by McGraw Hill in 2013, 73% of those surveyed said that home buyers will pay more for a green home. This is up from 61% in 2011.

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