Musings of an Energy Nerd

Passivhaus Windows

Posted on October 2, 2009 by Martin Holladay

UPDATED on June 11, 2013 with new information on European 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 windows available in the U.S.

German windows, like German cars, have a very solid reputation for high performance and durability. U.S. interest in German windows has grown in recent years, especially among Passivhaus builders, leading several U.S. importers to conclude that the time is ripe to offer German windows to North American customers.

Martin’s Useless Products List

Posted on September 25, 2009 by Martin Holladay

Every day, marketers convince hundreds of people to spend money on useless “energy saving” gadgets. Since these marketers show no signs of going away, it’s time to highlight their products with a ten-worst list.

Pinpointing Leaks With a Fog Machine

Posted on September 18, 2009 by Martin Holladay

In the last few years, energy consultants have developed a quick and easy way to pinpoint air leaks in a building envelopeExterior components of a house that provide protection from colder (and warmer) outdoor temperatures and precipitation; includes the house foundation, framed exterior walls, roof or ceiling, and insulation, and air sealing materials.. The technique uses a theatrical fogTo fog a room or building is to use a fog machine during a blower door test, revealing locations of air leaks where the fog escapes. The fogging material is usually a glycol-based solution, completely non-toxic. machine — a small, inexpensive device that creates smoke-like fog for dances, Halloween parties, or theatrical events. Fog machines have heating elements that vaporize “fog juice,” a solution of water and glycol or water and glycerin.

With the help of a blower door or a window fan, a fog machine can dramatically reveal holes in a building envelope.

‘Insulating’ Paint Merchants Dupe Gullible Homeowners

Posted on September 11, 2009 by Martin Holladay

Scammers have been selling “insulating” paint to gullible consumers for at least 27 years. Among the exaggerated claims made by distributors of these overpriced cans of paint is that the “low-e” coatings will “lower energy bills.” In addition to liquid paint, some fraudsters sell powders or paint additives, usually described as “miracle” products containing “micro-spheres” or “ceramic beads.”

The Jevons Paradox

Posted on September 4, 2009 by Martin Holladay

UPDATED with new photo on May 6, 2011

Let’s say you’ve sold your old, leaky house and moved into a new, well-insulated home with Energy StarLabeling system sponsored by the Environmental Protection Agency and the US Department of Energy for labeling the most energy-efficient products on the market; applies to a wide range of products, from computers and office equipment to refrigerators and air conditioners. appliances. With all of its efficiency improvements, your new home requires 30% less energy than your old home. That’s got to be good for the planet, right?

Well, maybe not — especially if you save so much on your energy bills that you decide to fly to Florida for your next vacation.

Solar Hot Water

Posted on August 28, 2009 by Martin Holladay

If you’re aiming to reduce your carbon footprintAmount of carbon dioxide and other greenhouse gases that a person, community, industry, or other entity contributes to the atmosphere through energy use, transportation, and other means. , you’ve probably thought about installing a solar hot water system. Here’s the good news: if you have an unshaded south-facing roof, you can install a solar hot water system that will meet about half your annual hot water needs.

The bad news: the typical solar hot water system costs between $6,000 and $10,000.

Can Foam Insulation Be Too Thick?

Posted on August 21, 2009 by Martin Holladay

In the U.S., designers of cutting-edge superinsulated homes generally recommend 2 to 6 inches of rigid foam insulation under residential slabs. For builders who use extruded polystyrene (XPSExtruded polystyrene. Highly insulating, water-resistant rigid foam insulation that is widely used above and below grade, such as on exterior walls and underneath concrete floor slabs. In North America, XPS is made with ozone-depleting HCFC-142b. XPS has higher density and R-value and lower vapor permeability than EPS rigid insulation.), the most commonly used sub-slab insulation, that amounts to R-10 to R-30.

The History of the Chainsaw Retrofit

Posted on August 14, 2009 by Martin Holladay

To achieve the carbon reductions needed to prevent a global ecological catastrophe, almost every house in North America will need a deep-energy retrofit. If the projecting elements on a home’s exterior — especially the eave and rake overhangs — can be stripped away, the best retrofit option is to wrap the exterior of the house with an airtight membrane and a deep layer of insulation, followed by new siding, roofing, and windows.

Getting Insulation Out of Your Walls and Ceilings

Posted on August 7, 2009 by Martin Holladay

More and more builders have realized the advantages of leaving stud bays empty and putting all of a home’s insulation outside of the wall and roof sheathingMaterial, usually plywood or oriented strand board (OSB), but sometimes wooden boards, installed on the exterior of wall studs, rafters, or roof trusses; siding or roofing installed on the sheathing—sometimes over strapping to create a rainscreen. . If done correctly, exterior insulation can help produce a building that is almost airtight, very well insulated, and almost immune to water damage.

High-Solar-Gain Glazing

Posted on July 31, 2009 by Martin Holladay

Homeowners can now receive a federal tax credit for 30% of the cost of new energy-efficient windows. The credit was authorized by the American Recovery and Reinvestment Act (ARRA) signed by President Obama in February.

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