Location Efficiency and Housing Type

According to this EPA study, regardless of the type of housing, living in an area with good transit access saves more energy than building a “green home”. Of course, living in a mixed use, transit accessible apartment that’s also energy efficient uses the least energy, but it’s important to realize how limited the potential for cost-effective energy efficiency is in a sprawling suburban context.

Leveraging digital design in synthetic biology

Automatic Design of Digital Synthetic Gene Circuits from PLoS Computational Biology.  They seem to be saying look, real biology isn’t generally digital, and all that continuum behavior means we need a bunch of new and complex tools to do anything with it.  However, there are plenty of instances of pseudo-digital biological control systems, and we’ve already got a gigantic toolbox from EE/VLSI world for building very complex digital circuits, so why not limit ourselves to using an artificially digitized subset of biology so we can leverage the existing design tools, and see how far we get?  Weird to think of this particular kind of very intimate digitization of life.  Talk about historical effects.  What would our post-dark-age descendants think, rediscovering a strange class of metabolic networks, in which everything is binary?

Into Eternity by Michael Madsen

I am now in this place where you should never come.  We call it Onkalo.  Onkalo means hiding place.  In my time it is still unfinished, though work began in the 20th century when I was just a child.  Work will be completed in the 22nd century, long after my death.  Onkalo must last 100,000 years. Nothing built by man has lasted even a tenth of that time span.  But we consider ourselves a very potent civilization.

If we succeed, Onkalo will most likely be the longest lasting remains of our civilization.  If you, some time far into the future find this, what will it tell you about us?

It isn’t often that you find people seriously thinking about deep time in a concrete way.  Usually it’s abstract, just a thought experiment, not an engineering problem or a gut wrenching moral quandry.  But this is apparently not the case for the Scandinavians who have taken on the task of storing their spent nuclear fuel.  Finland has decided to go forward with permanent storage, in a typically responsible, deliberate, earnest Nordic way.

Continue reading Into Eternity by Michael Madsen

The (HVAC) Elephant in the Room

A look at the difficulties of getting good HVAC design in high performance homes.  Most HVAC professionals are not familiar with the design requirements of very energy efficient homes with tight envelopes.  Most rules of thumb and the very basic modeling that is done in support of sizing the systems implicitly assume a “code” home… which is the least efficient house you can build without getting sued.  Oversized systems cause different problems than undersized ones, but they’re still significant problems.  As high performance homes become more common, more people are running into these issues.  Better contractor, builder, and homeowner education is needed.

Toward a Zero Energy Home by David Johnston and Scott Gibson

I’ve been looking, apparently in vain, for a good book (that’s not in German!) detailing Passive House building and modeling techniques.  The best I’ve been able to do so far is Toward a Zero Energy Home, and it must have been pretty good, since I read it cover-to-cover in less than 24 hours.  It’s not particularly dense or detailed, but it was a nice quick overview of low energy building systems, with lots of pretty pictures, and a dozen case studies from all over North America, including a couple right here in Boulder.

Refurbished with passive house components, kindergarten in Estonia Valga

The goal that the authors have chosen to highlight — “Net Zero” — means that the buildings in question produce as much energy as they consume on an annually averaged basis.  This necessarily means that they all have some on-site production, wind, PV, solar-thermal hot water, etc.  However, to keep such projects reasonably cost effective, it’s necessary to focus first on energy efficiency measures.  Most important among these is a very tight building envelope, much more insulation than code requires, and appropriate glazing for passive solar gain.  Then the internal power loads need to be minimized, by using energy efficient appliances and LED or CFL lighting.  Only after doing all that is it financially worthwhile to start adding on-site renewable generation, capable of meeting the overall annual energy demands of the dwelling.  Financially worthwhile, that is, if you have already decided that you want to create a Net Zero building.

Continue reading Toward a Zero Energy Home by David Johnston and Scott Gibson

German Passive House building robots

A short video from German home fabricator Hanse House.  They do both stock and custom homes, but both are fabricated off-site.  The video shows their production facility, and some of the techniques for putting together a building in pieces.  It’s pretty awesome.  Half robotic assembly line, and half humans, building to what’s essentially a CAD specification, with pipes and wires already laid in place within the structural elements before it gets loaded on the truck that takes it off to the building — or rather assembly — site, where the foundation awaits:

And here’s a time-lapse of one of their Passive Houses being assembled on-site:

I wonder if they do multi-family buildings too.  What it would take to get a facility like this operating in Boulder County?  Other than a rebound in the housing industry of course.

Boulder’s Passive Aggressive Building Standards

Usually when people say that “better is the enemy of good enough”, they’re pointing out that striving for perfection can be a distraction from just getting the job at hand done.  There are other dynamics that involve these concepts too.  As social animals, we tend to judge ourselves against those around us.  Once our basic needs have been satisfied, our relative wealth or deprivation often becomes more important to us than our absolute level of well being.  We have little concept of how much is enough.  This can lead to the familiar runaway acquisitiveness (keeping up with the Joneses) when there is a well established (or constructed…) social norm favoring consumption.  Less obviously, it can also lead to an inappropriate lack of ambition when faced with an objective task that is not supported by widespread social norms.

Over the last couple of years Boulder has upped its building energy efficiency standards.  The new permitting regime requires buildings to perform better — net of on-site generation like photovoltaics — than the 2006 international building codes (IBC).  Smaller dwellings (< 3000 square feet) have to use 30% less energy than the baseline.  Medium homes (3000-5000 sq ft) need to do 50% better, and large ones (> 5000 sq ft) have to beat it by 75%.  Obviously this is an improvement over the previous situation, but in comparison to what is possible, and what is necessary to combat climate change, it’s actually pretty unimpressive.  Homes of all sizes built to the Passive House standard use 80-90% less energy than the baseline code, and they do it without counting any on-site power generation against the building’s energy consumption, whereas the HERS index that is used in the Boulder code does count on-site generation.  This is an important distinction, because the atmosphere doesn’t cancel out your nighttime coal-fired emissions with the solar electricity that you sell onto the grid during the day.  All it cares about is the total amount of CO2 released.

Continue reading Boulder’s Passive Aggressive Building Standards

Links for the week of December 9th, 2010

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Continue reading Links for the week of December 9th, 2010

Links for the week of December 3rd, 2010

If you want to follow my shared links in real time instead of as a weekly digest, head over to Delicious. You can search them there easily too.
Continue reading Links for the week of December 3rd, 2010