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Dealing with Wildfires and Drought

October 31, 2007 By 4 Comments


Wildfires aren’t usually on my radar, because I don’t live in a region that is much susceptible to them. But, in the past couple of weeks, everyone has become more aware of them. They have been widely across the news because of the number of serious wildfires in southern California recently. At the same time, recent news coverage has also looked at drought conditions which are being felt in Georgia and North Carolina. While these two are be peripherally linked in other ways, it makes some sense to look at these issues from the perspective of sustainable building.

Addressing the issue of preparation for these extreme conditions as part of a sustainable building strategy only makes sense. Water use and xeriscaping (drought tolerant landscaping) are issues that are included in the LEED rating system, and are well regarded as part of the overall sustainability of buildings. But addressing a building and it’s site in terms of wildfires should be equally considered for regions where fire susceptibility is high. Keeping the building from burning down is also an issue of conservation of resources and should be part of a green building approach.

The Efficient Materials Trap

October 29, 2007 By 10 Comments


Efficient materials can sometimes seem to be the ideal path for green building. If we can find a way to more efficiently produce the materials we need to build our buildings, it would seem that we would be well on our way to reducing our impact on the planet.

For example, rather than using lumber sawn from old growth forests, engineered lumber and I-joists make more efficient use of lumber resources and can take advantage of smaller trees. Instead of needing to find trees old enough and large enough to produce a piece of 2 x 12 lumber, an engineered I-joist can be made that uses chipped wood and glue manufactured wood board (like oriented strand board) and narrow, laminated strips of wood (again, made of smaller pieces of wood and glue). These engineered joists are lighter, straighter, and less prone to warping, cupping and twisting than even kiln dried sawn lumber is.

Engineered joists would seem to be an ideal solution. They are made from small, rapidly renewable trees, which can be farmed, rather than requiring the logging of large trees. Builders and carpenters like them because they are more regular, and they make for flatter floors, straighter walls, and truer roofs, with less variability when they are installed and less likelihood to move and twist over time.

But there are downsides to these more efficient materials.

Green Building Elements: Building Controls

October 24, 2007 By Leave a Comment

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<img src="/files/111/613px-Honeywell_thermostat.jpg" alt="wikimedia" width="249" height="244" align="right" />For all our technological advances, our buildings remain incredibly dumb constructions. Automobiles have multiple onboard computers that help maximize their performance and improve efficiency and coordinate the various systems. But the average house has very little, if any, control to aid in its operation despite the wide range of conditions (from below freezing winter nights to scorching summer days) they are forced to deal with. Even large, complex buildings operate with fairly minimal control systems. Yet we expect them to provide a standard comfortable environment for us year round.
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We need some smarter building controls.
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Some building controls are already available. The oldest and best known is the simple thermostat. A thermometer control that turns on heating or cooling, depending on the temperature. It doesn't do much, but it does help to regulate furnaces and air conditioners to keep the temperature within a range of few degrees. But, temperature is not the only factor in comfort. Reducing the humidity can sometimes be all that is needed in warm weather. If the temperature is not too hot, the cooling effect of a breeze may be better than running an air conditioner. But a thermostat can't do that for you.</p>

Prohibited Green Technologies

October 22, 2007 By 3 Comments


Green technologies make good sense to most of us, but incomplete or uncoordinated implementation can lead to circumstances where green technologies are not able to provide the full benefits that they can. In some instances, regulatory requirements can even lead to making green technologies counterproductive.

Waterless urinals present one striking example of how regulations and green technology are not yet working together. In some municipalities, waterless urinals have not been allowed by building inspectors because they do not meet code requirements. Or, in some cases, building inspectors have allowed waterless urinals to be installed, but have required the builder to provide plumbing supply lines to bring water to the waterless urinal locations (though capped off and hidden behind the finished wall). The rationale for this is that if the waterless urinals are later removed and replaced with conventional urinals, extensive renovation will not be necessary to bring water to the location.

This upsets many of the green benefits of using waterless urinals in the first place. While waterless urinals provide water savings, that is not the only green benefit to incorporating them into a green building. Waterless urinals, when installed without a water supply line, provide savings in materials by avoiding the installation of likely dozens of feet of water supply pipe. Given the material cost, the high embodied energy content, and the extensive mineral use in mining, refining, and creating even ten feet of copper pipe, much of the savings from installing a waterless urinal is wiped out. Because of this, it will take much longer to realize the savings that using a waterless urinal should provide.

Terra Preta for Carbon Reduction

October 17, 2007 By 10 Comments


Terra preta (or agrichar, as it is also sometimes called) is not a new concept, but it is probably unfamiliar to most readers. The term terra preta refers to rich black soils found in the Amazon. These soils are not natural, but were human-made, produced by the civilizations living in the region before the arrival of Western settlers. The terra preta has a high level of nutrients, with three times the nitrogen and phosphorus and twenty times the carbon of normal soils. But producing fertilizer is not even the most interesting part of agrichar. The agrichar process also releases gasses which can be used as fuel for electrical generation or even for powering vehicles, and, most interestingly of all, more carbon goes back to the earth than was released in the process.

The process of producing agrichar uses low-temperature burning (called pyrolization) to break down the plant materials and produce two products, syngas and char. Syngas is mostly carbon monoxide and hydrogen, and can be used as a fuel for electrical production. (Wood gas, which is very similar to syngas, has widely used in the past for lighting, heating, and as a fuel for internal combustion engines.) The char turns out to be a good soil amendment that helps fertilize the soil. More importantly, the carbon that has been captured in the char breaks down very slowly so it remains sequestered for a long period of time.

"[B]urn biomass (preferably agricultural waste) in a special way that pyrolisizes it, breaking down long hydrocarbon chains like cellulose into shorter, simpler molecules. These simpler molecules are more easily broken down by microbes and plants as food, and bond more easily with key nutrients like nitrogen and phosphorus. This is what makes terra preta such good fertilizer. Because terra preta locks so much carbon in the soil, it’s also a form of carbon sequestration that doesn’t involve bizarre heroics like pumping CO2 down old mine shafts."

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