Building Technology

The Federation of American Scientists has just released its latest tool to improve energy efficiency, sustainability, healthfulness, and safety in the affordable housing market.

In cooperation with six Habitat for Humanity affiliates from all over the U.S. and experts at the Florida Solar Energy Center (FSEC), Pacific Northwest National Laboratory (PNNL), and Lawrence Berkeley National Laboratory (LBL), FAS has created The High Performance Building Guide for Habitat for Humanity Affiliates.  Funded by the Building Technologies Program at the U.S. Department of Energy, the goal of this Guide is to provide Habitat’s construction partners (called affiliates) with the knowledge, resources, and basic background to make educated decisions about improving their building practices, materials and technology choices, and decision-making and planning processes.

Targeted to the needs of the Habitat for Humanity building community, this Guide features profiles and case studies of excellent Habitat affiliates, practical recommendations and steps for improving building practices and decisions, and guidance on obtaining the partners, education, and resources necessary to make the transition to higher performing housing.

Get the High Performance Building Guide on the FAS website here.

To learn more about the Guide and to read a synopsis of its contents, check out the new Earth Systems Program blog.

Because a kilowatt saved is a penny earned.

Actually, the average cost of 1 KW of electricity in the US as of September 2009 was 12.6¢.  And while this figure doesn’t seem very large, all those cents add up when you consider that an average household consumes more than 34,000 KWH of electricity annually, including about 1200 KWH/Year to run each refrigerator and even more to run a plasma screen TV.  And when you add in the natural gas, fuel oil, kerosene, and wood used to heat houses, run hot water tanks, and operate ovens and other appliances, that’s even more energy consumed and more ways for you to begin cutting your energy costs.

In celebration of National Cut Your Energy Costs Day, which is Sunday, January 10th, FAS has provided a brief list of easy steps  you can  take  to cut your energy use, energy costs, and carbon footprint.  While this list is by no means comprehensive, use it as a starting point to think about how you can begin cutting your energy consumption  today, this month, and over this coming year.  Why not make your New Years resolution to consume less energy in your home?  And as you implement this resolution, we welcome your input into the best ways you have found to reduce your energy consumption and costs.

What you can do today:

-Set your thermostat down to 55 degrees or less at night and when you’re away from the house.

- Caulk and weatherstrip around windows and door that have gaps or where the seam is not adequately sealed.  You can also use a removable caulk to seal windows that you will use in the summer—when the weather warms up, you can just peel off the strip of caulk.

-Reduce “vampire power” in your house by unplugging appliances and electronics when not in use (especially electronics that stay in “stand by” mode such as TVs and computer).

-Visit the Home Energy Saver, an online do-it-yourself energy audit tool that offers advice on how to save energy in your home.  Find it at: http://hes.lbl.gov/hes/.

What you can do this month:

-Upgrade to an Energy Star-rated programmable thermostat if you don’t have one.  Many local utilities and governments will provide and install a free programmable thermostat or will offer a subsidy or tax credits for installing one.

-Have a blower door test done to see where your house is leaking energy.  Many utility companies and some local/municipal governments will offer free or subsidized blower door tests.

What you can do this year:

-Based on the results of your blower door test, add and/or upgrade your house’s insulation.  Insulating around your ducts, in your attic, and in the basement or crawlspace especially is both highly effective and low in cost.

-If it’s time to upgrade your HVAC system, hot water heater, major appliances, or roof, look for Energy Star certified products, which can be found at: www.energystar.gov.  Note that not all Energy Star products are equal and make sure you compare to find those products with the greatest efficiency and lowest operating cost.   Don’t forget to look for state and local tax credits!

Over the opening days of the Copenhagen Climate Negotiations, which began this Monday, each country has been asked to consider how it can contribute to the 25-40% carbon emission reductions climate scientists believe to be necessary to keep climate change below the 2C mark.  Key issues at stake for the 170 nations represented include commitments to national and international carbon reduction emissions, financing of clean technologies and carbon emission reductions, and technology transfer to non-industrialized nations.   Leading up to the Copenhagen climate summit, deforestation has been primary focus of discussion as deforestation accounts for one-fifth of global carbon emissions and halting deforestation involves large financial investment, but no fundamental consumer behavior changes.  And with a Reducing Emissions from Deforestation and Degradation (REDD) agreement, developed nations would pay developing countries to not cut down their rainforests by treating the standing forest as a valuable commodity.  Such an agreement, if properly financed and implemented, will be necessary to meet global carbon emissions goals and avoid the numerous ecosystem and climate hazards associated with deforestation.

However, in order to meet national greenhouse gas abatement goals and make the economic and structural changes necessary to avoid or mitigate large-scale climate change consequences, industrialized countries must reduce both their total energy consumption and energy intensity.

Consuming 40% of all energy in the US and Europe and 30-40% worldwide, the building sector is one of the least energy efficient sectors and one in which efficiency investment has been generally highly fragmented, relying n the US on individual owners to finance energy efficiency new construction and retrofits.  Yet for many countries, especially the US and the European nations, cutting buildings sector consumption is not only essential to meeting these goals, but is also one of the most cost effective energy saving measures available (see the table from McKinsey, below). Furthermore, analysis by the World Business Council for Sustainable Development (WBCSD) indicates that market-driven reform can reduce building energy use by 60% by 2050, but will require a concerted and immediate effort on the part of industry, government, code and standard making bodies, and labor in order to achieve.

Graph demonstrating the cost effectiveness of buildings energy efficiency (McKinsey)

Looking at energy use in the residential sector as a case study, according to the 2005 Residential Energy Consumption Survey 59% of houses in the US were built before 1980 and in the vast majority of cases have not been substantively renovated or retrofitted. These hugely inefficient houses feature little or no insulation in the attics, walls, and foundations, inefficient HVAC systems, leaky ducts, poor air sealing, outdated windows and doors, and are often expensive to operate due to high energy waste rates, especially during peak heating and cooling periods.

US households spend on average just over $1800 annually on house energy consumption, with over 40% of that energy consumed in maintaining thermal comfort through space heating and air conditioning. However, energy consumption reductions of up to 50% have been proved cost effective in both the retrofit and new housing market by focusing on insulating and air sealing to reduce heating and cooling costs.  In the retrofit market, the efficacy of energy efficiency retrofits in decreasing annual operating costs of a building through energy savings is supported by analysis of the DOE Weatherization Assistance Program.  Independent reports conclude that for every $1 spent to weatherize a house (up to $5000 under the current program), the occupants save $1.67 in utility costs, a savings achieved through measures such as adding insulation, air sealing, installing airtight doors and windows, and occasionally upgrading HVAC equipment and ducts.

In the new homes market, Habitat for Humanity affiliates across the country have succeeded in building affordable housing units that are up to 50% more energy efficient to operate (achieving HERS scores in the low to mid-50s), feature materials with low embodied energy, and are cost-effective, saving the families hundreds of dollars per year in operating costs. (To see case studies on high performance Habitat building, see upcoming FAS report titled “Habitat for Humanity High Performance Building Guide”.)

The US Federal Government has begun to address the need for improved energy efficiency in the building sector through legislation in areas such as:  investments in weatherization (the American Recovery and Reinvestment Act of 2009), commercial and residential energy efficiency tax credits (among others, the Energy Improvement and Extension Act of 2008), federally backed energy efficient mortgages, and setting energy use goals and standards for federal buildings (the Energy Policy Act of 2005 and Executive Order 13423 of 2009).  However, all current US energy legislation will save only a fraction of President Obama’s recently announced target of 17% energy savings by 2020.  My comparison, the European Commission has just tentatively approved an “Energy Performance of Buildings Directive,” which mandates that all new construction be “near zero energy”; this directive is estimated to have the potential to reduce the EU’s greenhouse gas emissions by 70% of their energy savings target of 20% by 2020.

In order to fulfill any promises that are made at Copenhagen over the coming days and weeks, the US will need to set an ambitious buildings energy efficiency target akin to that approved by the European Commission.  This target must be supported by both public and private action and investment, including:  government legislation, incentives, and workforce training; private sector financial investment and the development of a strong, competitive, energy efficiency market; technological innovation both from industry and the national labs; and the rapid development and deployment of high performing building energy codes and standards.

You can meet up with friends, go shopping for high fashion clothing, browse through a fanciful New York City, and build your dream house.  You can also participate in your company’s annual conference, practice patient care in an O.R., and attend a lecture by a Harvard professor.  All in the Second Life virtual world.  And recently added to that list of activities to do in Second Life is: learn how to inspect a home built from structural insulated panels (SIPs), an advanced, energy efficient building system.

But why construct a building inspector training module in Second Life?

Both the American Clean Energy and Security Act of 2009 and in the American Recovery and Reinvestment Act of 2009 set aside billions for energy efficiency and energy savings programs and green industries.  A key aspect of these bills is the creation of “green” jobs and training workers to fill these positions, with a strong emphasis on existing home weatherization and retrofits.  After all, the building sector in the United States currently use more energy and more electricity than any other sector, and much of this energy is lost to inefficient structures with a leaky thermal envelope and poor (or no)  insulation.  Substantively reducing energy demand therefore requires a combination of constructing more energy efficient, sustainable new buildings and performing deep retrofits on existing buildings.  Doing so will save money at both the household and national levels and will decrease our nation’s carbon emissions from energy.

The federal government has appropriated money to advance the state of energy efficient housing technologies and subsidize retrofits and new construction projects.  However, neither retrofits nor new construction can take place without a well-trained workforce of architects, engineers, building professionals, tradesmen, and code officials who know how to design, built, and inspect energy efficient structures.  At present, many industry professionals have no experience with or training in how to properly utilize advanced building technologies and materials and this lack of training and experience has proven to be a huge barrier to their adoption.  And so in order to transition the building industry into a more efficient and sustainable sector, tools and programs must be rapidly developed to train industry professionals in energy efficiency theories and practical applications.

In order to train workers effectively within a short period of time, the tools must be virtually based to eliminate geographical restrictions, they must be interactive and engaging to enable learning, and they must be able to simulate scenarios and situations in the real world, promote collaboration between students and instructors, and provide the means by which to learn through problem solving and independent exploration.  And at the present time, one of the only tools available that fulfills all of these requirements is virtual world technology.

To assess the utility of virtual worlds to building industry training, the Federation of American Scientists Building Technologies Program has created a pilot training module for building inspectors that utilizes the Second Life virtual world and web-based tools.  This module educates building inspectors about how to inspect houses constructed with structural insulated panels (SIPs).  In this interactive virtual environment, building inspectors can investigate structural and architectural details, interact with animated models, click on details to obtain descriptions, CAD Images, and drawings of the detail, watch a presentation, and take a self-assessment of knowledge gained.  Through these features, users learn about the importance of energy efficiency and how to achieve a tight building envelope, constructability and code compliance issues commonly found in SIP construction, and information about SIPs themselves.

While not a fully functional pilot, initial feedback indicates that virtual worlds are indeed valuable training tools, especially when coupled with an independent web-based learning module.  By combining classroom learning with field-based learning scenarios, virtual world training improves comprehension of classroom material and shortens the in-field learning curve, thereby speeding up the training process.  And due to its web-based nature, virtual world training can allow students to be trained in areas of the country where there are few trainers or certified professionals.  As such, FAS recommends further development of virtual training modules as a solution to the need to train workers for a more energy efficient building sector.

To read the Building Technology Program’s report to Lawrence Berkeley National Lab on the training, click here.  To visit the building inspector training module in Second Life, teleport to: 142, 18, 27.

In the ongoing efforts to reduce our nation’s carbon output by improving the energy efficiency of our built environment, a new old idea is shaping up to be a key player: cool roofs.  Used throughout the Mediterranean and tropical climates worldwide, the solar reflectance value (albedo) of a white or light-colored roof has been long understood—the more sunlight the roof reflects, the less the building absorbs and the easier it is to keep the building cool.

A recent report by Hashem Akbari, Surabi Menon and Art Rosenfeld titled, “Global Cooling: Effect of Urban Albedo on Global Temperature”, quantifies cool roofs’ potential impact on improving energy efficiency and slowing climate change.  The report notes that painting 100 feet² of black roof a lighter color offsets the extra heating caused by 1 metric ton of CO₂ in the atmosphere.  Scaled up to the national level, converting dark-colored roofs and pavements in urban areas around the world to lighter colors would offset the extra heating caused by 44 billion metric tons of CO₂in the atmosphere, effectively offsetting over 6 years of the U.S.’s CO₂ equivalent greenhouse gas output and saving the country over $1 billion per year in energy costs.

Clearly, cool roofs are a big deal.  But from a building technology perspective, just painting the roof a lighter color isn’t enough, since the lighter color only solves half of the cool roof equation.  Calculating the coolness of a roof requires measuring both solar reflectance (the fraction of solar energy reflected by the roof) and thermal emittance (the measure of a roof’s ability to radiate absorbed heat as infrared light); the most useful method available for calculating roof coolness is the solar reflective index (SRI).  This index utilizes both factors to generate a 1-100 SRI rating, where 100 indicates a roof with perfect solar reflectance and thermal emittance.  The higher the SRI, the cooler a roof will be, even in full sunlight on a hot day.

Much like the HERS index for whole house energy efficiency, this rating index is essential to meeting the goal of retrofitting and constructing new buildings with cool roofs.  Without a scientifically sound method to rate the cooling properties of various roofing materials, consumers cannot make educated decisions and the maximum cooling benefits cannot be harnessed.

And while many current cool roof materials apply the latest and most advanced technologies, from spray polyurethane foam systems to brightly-colored tiles that reflect infrared energy, our historic understanding of the relationship between color and solar reflectance retains its preeminent importance.  Lighter roofing materials keep buildings cooler than darker materials, yielding more energy efficient structures that have a lower carbon footprint and are less expensive to operate.

Resources on Cool Roofs:

Hashem Akbari, Surabi Menon and Arthur Rosenfeld, “Global Cooling: Effect of Urban Albedo on Global Temperature”, 2008.  http://repositories.cdlib.org/lbnl/LBNL-63490/

Energy Information Administration, “Emissions of Greenhouse Gases Report”, December 2008.  http://www.eia.doe.gov/oiaf/1605/ggrpt/

The Lawrence Berkeley National Laboratory (LBNL) Cool Roofing Materials Database. http://eetd.lbl.gov/coolroof/

The Cool Roof Rating Council (CRRC).  http://www.coolroofs.org/

Celeste Allen Novak and Sarah Van Mantgem, “What’s So Cool About Cool Roofs”, GreenSource, March 2009.  http://continuingeducation.construction.com/article.php?L=68&C=488&P=1

The DOE Cool Roof Calculator provides an estimate of cooling and heating savings for small to medium size facilities that purchase electricity with a demand charge and an alternative version for larger facilities. http://www.ornl.gov/sci/roofs%2Bwalls/facts/CoolCalcEnergy.htm

The EPA Cool Roof Calculator allows the designer to input specific details about a building, including heating and cooling systems as well as location and the cost of energy. http://www.roofcalc.com/RoofCalcBuildingInput.aspx

A PDF version of this document is available here.