The most recent blogs at Green Building Advisor

A Passivhaus Doesn’t Have to Look Weird

Posted on April 1, 2014 by alan abrams in Guest Blogs

Does a 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. have to look weird? The short answer is, no.

Passive House Training, One Year Later

Posted on March 31, 2014 by Robert Swinburne in Guest Blogs

I have been asked about my 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. Consultant training by other architects enough times that I thought I’d write up a quick synopsis, one year later.

For me, the training was very useful for several reasons, not the least of which was the networking aspect. It is a small community with some really great conversation happening and it is fun to be a part of that.

Deep Energy Retrofits Are Often Misguided

Posted on March 28, 2014 by Martin Holladay, GBA Advisor in Musings of an Energy Nerd

All through the 1980s and 1990s, a small band of North American believers worked to maintain and expand our understanding of residential energy efficiency. These were the pioneers of the home performance field: blower-door experts, weatherization contractors, and “house as a system” trainers. At conferences like Affordable Comfort, they gathered to share their knowledge and lick their wounds.

These pioneers understood what was wrong with American houses: They leaked air; they were inadequately insulated; they had bad windows; and their duct systems were a disaster.

Reinventing Concrete

Posted on March 27, 2014 by Alex Wilson in Energy Solutions

I’ve been in the San Francisco Bay Area for the past week speaking at various conferences. (When I travel I try to combine activities to assuage my guilt at burning all the fuel and emitting all that carbon dioxide to get there. Between conferences, I’m now spending time with my daughter in Petaluma and Napa.)

An Interview with Dr. Iain Walker on Ventilation

Posted on March 26, 2014 by Allison A. Bailes III, PhD, GBA Advisor in Building Science

The debate over how much to ventilate a home has been going on a long time. Last year, Building Science Corporation introduced its own standard to compete against ASHRAE 62.2A standard for residential mechanical ventilation systems established by the American Society of Heating, Refrigerating, and Air-Conditioning Engineers. Among other requirements, the standard requires a home to have a mechanical ventilation system capable of ventilating at a rate of 1 cfm for every 100 square feet of occupiable space plus 7.5 cfm per occupant. because (according to Dr. Joseph Lstiburek) of problems that weren't adequately addressed in the 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. standard. I've written about the standard and interviewed Lstiburek and ASHRAE 62.2 committee chair Paul Francisco. (See links at bottom.)

Disaster Responses

Posted on March 25, 2014 by Paul Eldrenkamp in Guest Blogs

In this blog I will periodically discuss particular numbers and other metrics that I think can be of value in helping you run your business.

In this installment, I discuss the concept of “triage,” which ultimately derives from the Latin word for “three.” Literally and historically, “triage” refers to a simple way of allocating emergency medical care among a group of injured people who outnumber available medical resources.

In its original form — dating from the Napoleonic Wars — these were the three categories to consider when doing triage:

Fixing a Leaky Log Home

Posted on March 24, 2014 by Scott Gibson in Q&A Spotlight

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.

Stay Away from Foil-Faced Bubble Wrap

Posted on March 21, 2014 by Martin Holladay, GBA Advisor in Musings of an Energy Nerd

Most brands of foil-faced bubble wrap are only 3/8 inch thick or less, and have an R-valueMeasure of resistance to heat flow; the higher the R-value, the lower the heat loss. The inverse of U-factor. of only 1.0 or 1.1. Since the product often costs more per square foot than 1-inch thick rigid foam rated at R-5, why would anyone use bubble wrap as insulation?

Lessons From Our House That Could Be Applied More Affordably

Posted on March 20, 2014 by Alex Wilson in Energy Solutions

My wife and I tried out a lot of innovative systems and materials in the renovation/rebuild of our Dummerston, Vermont home — some of which added considerably to the project cost. Alas!

The induction cooktop that I wrote about last week is just one such example.

For me, the house has been a one-time opportunity to gain experience with state-of-the-art products and technologies, some of which are very new to the building industry (like cork insulation, which was expensive both to buy and to install). We spent a lot experimenting with new materials, construction details, and building systems. While we haven’t tallied up all the costs, we think that the house came in at about $250 per square foot.

Induction Cooktops, Steve Jobs, and a Lone Nut Dancing

Posted on March 19, 2014 by Allison A. Bailes III, PhD, GBA Advisor in Building Science

Last Friday was Pi Day, named for that special number, 3.14159265358979323846264338327950288...

The three dots at the end mean that I've exhausted my memory of the digits of pi, but pi doesn't care. It just goes on and on. Anyway, Pi Day is a perfect day for a physics lesson because so many physics equations (and solutions) use that special number. And what better physics lesson for Pi Day than one about a device that cooks yummy things for us!

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