Musings of an Energy Nerd

A Superinsulated House in Rural Minnesota

Posted on March 16, 2012 by Martin Holladay, GBA Advisor

Electric resistance heating systems have a bad reputation. While the required equipment is cheap (and sometimes cheap-looking), homes with electric heat are known for their high fuel bills.

Occupant Behavior Makes a Difference

Posted on March 9, 2012 by Martin Holladay, GBA Advisor

Energy experts often repeat the cliché, “There’s no such thing as a zero-energy home — just zero-energy homeowners.” Energy monitoring data from two well-publicized Massachusetts homes — the so-called Montague Urban Homestead house in Turners Falls and the home of Matt and Laura Beaton in Shrewsbury — prove the cliché to be true.

The High Cost of Deep-Energy Retrofits

Posted on March 2, 2012 by Martin Holladay, GBA Advisor

How much does it cost to perform a deep-energy retrofit at a 100-year-old single-family home? Thanks to a recent study in Utica, New York, we now know the answer: about $100,000.

The research was sponsored by New York State Energy Research and Development Authority (NYSERDA), an agency that administers programs funded by public benefit charges tacked onto electric utility bills. The program paid for deep-energy retrofits at four wood-framed buildings in Utica, New York.

Carl and Abe Write a Textbook

Posted on February 24, 2012 by Martin Holladay, GBA Advisor

Carl Seville, this website’s resident green building curmudgeon and blogger, has teamed up with Abe Kruger, an energy rater and BPI Building Analyst, to write a new textbook, Green Building: Principles and Practices in Residential Construction.

An Introduction to Photovoltaic Systems

Posted on February 17, 2012 by Martin Holladay, GBA Advisor

By now, 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 are familiar to most Americans. You’ve seen them on your hand-held calculator, on top of illuminated highway signs, and maybe even on your neighbors’ roofs. With PV systems becoming more common, perhaps you’ve been dreaming of making some homemade electricity. The dream is achievable, as long as you own a sunny patch of lawn or an unshaded south-facing rooftop, and as long as you have a bank balance of several thousand dollars.

All About Water Heaters

Posted on February 10, 2012 by Martin Holladay, GBA Advisor

If you want to save energy, there are lots of exciting appliances and building materials that you might want to specify for your home: triple-glazed windows, an efficient refrigerator, and compact fluorescent or LEDLight-emitting diode. Illumination technology that produces light by running electrical current through a semiconductor diode. LED lamps are much longer lasting and much more energy efficient than incandescent lamps; unlike fluorescent lamps, LED lamps do not contain mercury and can be readily dimmed. lighting, for example.

When it comes to choosing a water heater, though, clarity evaporates. Simple, affordable water heaters aren’t very efficient, and efficient equipment is complicated and costly. So how do you go about choosing a water heater?

New Green Building Products — February 2012

Posted on February 3, 2012 by Martin Holladay, GBA Advisor

My folder of interesting new building products is getting thick, so it’s time for another new product roundup. I’ll review three brands of 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. roofing designed to integrate with asphalt shingle roofs. I’ll also discuss several new types of insulation: a new type of rigid foam, batts made from plastic fibers, and batts made from hemp.

Is This Building Passivhaus-Certified?

Posted on January 27, 2012 by Martin Holladay, GBA Advisor

UPDATED February 7, 2012 with a response from Wolfgang Feist

The first residential 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. building in Canada is the Rideau Residences, a duplex at 279 Crichton Street in Ottawa. The building has impressive specifications: an R-70 foundation, R-50 walls, an R-70 roof, and triple-glazed low-eLow-emissivity coating. Very thin metallic coating on glass or plastic window glazing that permits most of the sun’s short-wave (light) radiation to enter, while blocking up to 90% of the long-wave (heat) radiation. Low-e coatings boost a window’s R-value and reduce its U-factor. windows. The building’s air leakage rate was tested at 0.58 ach50.

Service Cavities for Wiring and Plumbing

Posted on January 20, 2012 by Martin Holladay, GBA Advisor

Conventional wood-framed walls perform many functions. Exterior walls are supposed to support the roof load, resist racking, and provide insulation. They must also provide space for routing electrical cables and (in some cases) plumbing pipes or even ductwork. If the walls are built properly, they should also include an air barrierBuilding assembly components that work as a system to restrict air flow through the building envelope. Air barriers may or may not act as a vapor barrier. The air barrier can be on the exterior, the interior of the assembly, or both..

Fukushima’s No-Entry Zone

Posted on January 13, 2012 by Martin Holladay, GBA Advisor

UPDATED February 27, 2012

Why is it that trivial news stories (for example, reports on Kate Middleton’s wedding dress) often receive disproportionate coverage, while important news stories are sometimes neglected?

Here’s my vote for the most neglected news story of 2011: the radioactive contamination of hundreds of square miles of land around the Fukushima-Daiichi nuclear plant in Japan. Although most news outlets have reported some details of this story, I think it deserves much more attention than it has received.

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