The most recent blogs at Green Building Advisor

Using David White’s Global Warming Calculator

Posted on December 7, 2016 by Allison A. Bailes III, PhD, GBA Advisor in Building Science

Everyone knows about the impact of burning fossil fuels on global warming. Maybe not everyone believes it, but scientists first started focusing attention on increasing carbon dioxide levels way back in 1827. The impact of insulation on global warming, however, is relatively new.

Passive House in China, Part 1

Posted on December 6, 2016 by Katrin Klingenberg in Guest Blogs

This year I was invited to give the keynote address at Passive HouseA 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. Alliance China’s 3rd China Passive Building Summit in Shanghai, with the explicit request to report on passive building progress in the U.S. and on PHIUS’ climate-specific standards.

In light of the immense amount of development currently taking place in China, with whole cities springing up practically overnight and a huge stock of existing buildings in need of energy efficiency upgrades, China’s interest in the passive building work being done in the U.S. is significant.

Best Path to Net-Zero Energy

Posted on December 5, 2016 by Scott Gibson in Q&A Spotlight

Joshua Greisen thinks he's found an ideal building lot in Yakima, Washington, a city in the south-central part of the state in Climate Zone 5B. Now, can he find a design for a zero-net-energy house to go with it?

Working with a limited budget, but on a south-facing lot ideal for passive solar gain, Greisen is looking for a cost-effective way of reaching his goal. "I'm by no means a rich man," he writes in a Q&A post at GreenBuildingAdvisor, "and can only afford to do what has a return on investment that will be realized within a decade or so."

Worries About Trapping Moisture

Posted on December 2, 2016 by Martin Holladay, GBA Advisor in Musings of an Energy Nerd

A significant number of questions posted by readers on the GBAGreenBuildingAdvisor.com site are variations of, “Will this wall detail (or roof detail) trap moisture?”

When I entered “trap moisture” into the GBA search box, I got 182 results. The search terms “trapping moisture” yielded another 104 results. Clearly, there is a high level of concern around the issue.

‘Peer Diffusion’ Can Make Better Homes a Must Have

Posted on December 1, 2016 by Anonymous in Guest Blogs

By DOUGLAS MILLER and LARRY ZARKER

Peer Diffusion: A form of communication within and between networks of people that (1) occurs through varying forms of social comparison and social interaction around an innovation (i.e., a new behavior, idea, or technology) and (2) ultimately promotes the broader adoption of that innovation.

Wolfe Island Passive: Building With Cross-Laminated Timber

Posted on November 30, 2016 by David Murakami Wood in Guest Blogs

Editor's note: David and Kayo Murakami Wood are building what they hope will be Ontario's first certified Passive HouseA 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. on Wolfe Island, the largest of the Thousand Islands on the St. Lawrence River. They are documenting their work at their blog, Wolfe Island Passive House. For a list of earlier posts in this series, see the sidebar below.

Biofuels Turn Out To Be a Climate Mistake

Posted on November 29, 2016 by John DeCicco in Guest Blogs

Ever since the 1973 oil embargo, U.S. energy policy has sought to replace petroleum-based transportation fuels with alternatives. One prominent option is using biofuels such as ethanol in place of gasoline and biodiesel instead of ordinary diesel.

Transportation generates one-fourth of U.S. greenhouse gas emissions, so addressing this sector’s impact is crucial for climate protection.

Making the Case for Prefab Zero-Energy Homes

Posted on November 28, 2016 by Bruce Sullivan in Guest Blogs

Because zero-energy homes are built to higher standards than most ordinary homes, they require greater attention to detail and often cost somewhat more. These two realities make zero energy homes especially well suited to the economies of scale, the speed of construction, and the precision industrial methods involved in modern prefab construction.

Cold Floors and Warm Ceilings

Posted on November 25, 2016 by Martin Holladay, GBA Advisor in Musings of an Energy Nerd

During the winter, the air near your floor is cold, while the air near your ceiling is hot. Similarly, during the summer, the air conditioner keeps your first floor comfortable, while the rooms on the second floor are unbearably hot. What’s going on?

The usual answer is, “Heat rises.” But that explanation isn’t quite accurate. (It’s true that hot air rises by convection. But heat travels in all directions, including sideways and downward, by conductionMovement of heat through a material as kinetic energy is transferred from molecule to molecule; the handle of an iron skillet on the stove gets hot due to heat conduction. R-value is a measure of resistance to conductive heat flow. and radiation.)

Break It or Lose It

Posted on November 24, 2016 by Andrea Love in Guest Blogs

Over the past 20 years, the building industry has experienced renewed interest in reducing the energy demand of buildings. At the building code level, groups such as the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAEAmerican Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE). International organization dedicated to the advancement of heating, ventilation, air conditioning, and refrigeration through research, standards writing, publishing, and continuing education. Membership is open to anyone in the HVAC&R field; the organization has about 50,000 members. ) have been steadily raising the bar on performance criteria for building envelopes and systems. Designers have been challenged to find and implement technologies and solutions that can practically and economically affect the energy demands of our buildings.

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