The most recent blogs at Green Building Advisor

Using Total Effective Length in Duct Design

Posted on July 26, 2017 by Allison A. Bailes III, PhD in Building Science

Today I’m going to explain an important concept in one of the most popular ways of doing duct design. I’ve been writing a series on duct design over at my blog and began with a look at the basic physics of air moving through ducts. The short version is that friction and turbulence in ducts results in pressure drops. Then in part 2 I covered available static pressure. The blower gives us a pressure rise.

Footings and Frost Walls at Flatrock Passive

Posted on July 25, 2017 by David Goodyear in Guest Blogs

Editor's Note: This is one of a series of blogs by David Goodyear describing the construction of his new home in Flatrock, Newfoundland, the first in the province built to the 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. standard. The first installment of the GBAGreenBuildingAdvisor.com blog series was titled An Introduction to the Flatrock Passive House. For a list of Goodyear's earlier blogs on this site, see the "Related Articles" sidebar below; you'll find his complete blog here.

Choosing the Cheapest Path to Net Zero

Posted on July 24, 2017 by Scott Gibson in Q&A Spotlight

Writing from northeast Ohio, a reader with the screen name “User-6877304” — let's call him Steve — is seeking comments on his plans to build an affordable 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. home. The house, to be built on a 30-foot by 50-foot slab-on-grade foundation, seems to have many characteristics of a "Pretty Good House" — that is, it's well insulated and ventilated but not attempting to hit the 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. metric.

Steve plans to install R-10 rigid insulation beneath the slab. The house will have double-stud walls insulated with cellulose to R-40 and a raised-heel truss roof insulated to R-60.

Crawl Spaces vs. Skirts

Posted on July 21, 2017 by Martin Holladay in Musings of an Energy Nerd

Many older homes in rural areas have pier foundations. The piers may be made of wood (for example, creosoted posts or pressure-treated lumber), poured concrete, CMUs, or bricks. The space between the dirt and the underside of the floor framing may be enclosed or may be entirely open to the wind.

Pete’s Puzzle: Mold on Painted Clapboards is Food for Thought

Posted on July 20, 2017 by Peter Yost in Building Science

Whenever my wife starts a conversation with, “OK, Mr. Building Scientist,” I know I am in some kind of trouble. That proved to be the case one day when we were out hanging laundry on the south side of our house.

Empowering Customers to Choose Clean Energy

Posted on July 19, 2017 by Anonymous in Guest Blogs

By JULES KORTENHORST and JAMES MANDEL

A Net-Zero Community in Texas

Posted on July 18, 2017 by lsichelman in Guest Blogs

By LEW SICHELMAN

Richard Bruce is looking forward to moving into his new Austin, Texas, home with his wife by year's end. When construction is complete, the 1,700-square-foot abode will have three bedrooms, two bathrooms, plus lightning-fast Google Fiber internet service. But here are the real selling points: the geothermal heating and cooling system and photovoltaic(PV) Generation of electricity directly from sunlight. A photovoltaic cell has no moving parts; electrons are energized by sunlight and result in current flow. (PVPhotovoltaics. Generation of electricity directly from sunlight. A photovoltaic (PV) cell has no moving parts; electrons are energized by sunlight and result in current flow.) panels which will ensure the new house produces as much energy as the couple consume.

Urban Rustic: Let the Framing Begin

Posted on July 17, 2017 by Eric Whetzel in Guest Blogs

Editor's note: This post is one of a series by Eric Whetzel about the design and construction of his house in Palatine, Illinois, a suburb of Chicago. The first blog in his series was called An Introduction to a New Passive House Project; a list of Eric's previous posts appears below. For more details, see Eric's blog, Kimchi & Kraut.

Air Conditioner Performance In Extreme Heat

Posted on July 14, 2017 by Martin Holladay in Musings of an Energy Nerd

During the last week of June, many major U.S. news outlets sent reporters to Arizona to issue updates on the area’s extreme heat wave. Outdoor temperatures hit 119°F in Phoenix. Some airplanes were grounded because the hot air was too thin for small jets to take off. Car steering wheels were so hot that some drivers wore oven mitts. VinylCommon term for polyvinyl chloride (PVC). In chemistry, vinyl refers to a carbon-and-hydrogen group (H2C=CH–) that attaches to another functional group, such as chlorine (vinyl chloride) or acetate (vinyl acetate). records delivered by mail arrived warped. Emergency room physicians reported an increase in burn cases: hands were burned when people touched their cars, and children’s feet were burned when they went barefoot outdoors.

An Award-Winning Efficiency Program in Colorado

Posted on July 13, 2017 by Laurie Guevara-Stone in Guest Blogs

Like other forward-thinking cities, Fort Collins — a city of 167,500 located in northern Colorado — had a goal to cut greenhouse gas emissions 80% by 2050. However, following a Rocky Mountain Institute e–Lab design charretteMeeting at the beginning of an integrative design process that sets the stage for cooperation and collaboration among all participants, including the design team, engineers, contractors, clients, and any others involved in the project. Early involvement of the entire project team is fundamental to the successful use of a systems approach to green building. , the city decided to see if it could push that goal up by 20 years.

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