Retrospective: Building Science Education in the Community College
Why aren’t we building more energy-efficient homes in this country? Technology and our understanding of home performance have evolved dramatically over the past ten years, but for the most part, these new technologies and techniques are not evident in the field. New technology suffers from slow acceptance, but basic energy-efficient building and design details are almost always missing as well. I have come to expect thermal defects (i.e., poorly installed and missing insulation, thermal bridging, and air intrusion), leaky duct systems, and a disregard for solar orientation and window placement in the design and construction of new homes. Lack of access to good information is one of the biggest obstacles to improving the efficiency of this country’s housing stock. Many architects and builders would design and build a better product if they were aware of the impact of their decisions, or if they were given good information about how to build efficient homes. The course I teach at Yavapai Community College in Prescott, Arizona—Energy- Efficient Building and Design: A Systems Approach—provides building professionals with the information and motivation they need to design and build more efficient homes. It also demonstrates that the community college system can be a successful and affordable vehicle for providing building-science education. The community college system can be used to make the building science perspective more accessible to the people who need the information most—builders and architects. Community colleges are strategically located and inexpensive, and the curriculum can be adapted to the local climate and the special needs of the local building community.
The most obvious benefit of teaching energy efficiency at a community college is its low cost. At Yavapai Community College in Prescott, Arizona, a semester-long, three-credit course costs only $90 (in 1998). Plus, the instructor can create a class that addresses regional weather patterns, building practices, local energy myths, and other indigenous concerns. For instance, if the course is being offered in a hot and humid climate, more time can be spent on moisture control and cooling strategies. Finally, most students attend a college-level course expecting that their performance will be evaluated. Homework enables people to learn at their own pace while testing gauges how well they are learning the material. For contractors and architects too busy to be bothered with homework and tests, however, college policy is flexible enough that they can attend the classes, lectures, and labs without worrying about a grade.
A Results-Oriented Curriculum
Course content should be relevant and should convey the systems approach to energy-efficient building and design. The course must be structured to insure that students leave the class with a firm grasp of the fundamentals. Architects and builders require practical information they can use in their businesses so the class must provide enough details to enable participants to design, build, test, and sell energy-efficient homes. Success is measured by the participants’ willingness to incorporate
energy-efficient building and design strategies into their projects. The curriculum must be grounded in the field, balancing principle and practice, as well as product and price information, to achieve the desired results.
Above all, builders and architects are busy people. Consequently, the content of the course has to address their needs, and the information must be presented in an engaging fashion. If the class falls short of this mark, students won’t return.
The curriculum for my course is organized around the “four Ps”: principles, practices, products, and prices. Principles form the core of the course and help students better understand the rationale behind the practices. Practices involve all of the steps taken to improve home performance. Practices are augmented by product and price information to complete the picture.
The first half of the course covers building-science principles such as heat transfer, air flow, moisture movement, and chemical and biological reactions, and how these forces interact with one another, the home, and its occupants. These interactions form the theoretical basis for a systems approach to energy-efficient building and design. The second half of the course takes a look at practices. The sequence of material is very important, because architects and builders need to know first why they are being encouraged to eliminate thermal defects and seal up duct systems. On a practical level, product and price information are as important as principles and practice to the professionals who have taken my course. Students need product and price information to form their own judgments about energy-efficient building and design strategies. For example, the installed cost of a heat-recovery ventilator is important information for practitioners deciding what type of system best suits their market’s needs. Builders and architects need information that is relevant in the field.
- What is the main prerequisite for building an energy-efficient home?
- What is a Btu (British thermal unit)?
- How many Btu are there in a therm? In a kilowatt?
- How many heating degree-days are there in a year in your community?
- What does AFUE stand for?
- What does the acronym VOC stand for? What is a VOC?
- Thermal comfort within buildings is primarily controlled by what four major factors?
- List three of the five principal thermal defects.
- What is the inverse of R-value and what does it represent?
- What air exchange/ventilation rate is most commonly recommended for homes?
- What is the most useful characteristic for evaluating a window’s ability to admit or repel solar radiation?
Uniacke’s students take this ungraded assessment test at the beginning of each semester. It gives them an idea of the kinds of things they'll be learning in the class, and by demonstrating how much they don't know, provides Uniacke with insurance against “know-it-alls.” Take the test and see how you do!
Answers at the end of the article.
I have developed a two-tiered approach to teaching building science. In essence, the first tier examines the goal—to build a house that is not only energy-efficient, but also affordable, healthy, safe, and durable—while the second tier describes how to achieve that goal.
The first tier covers health, safety, durability, comfort, and efficiency parameters and all the key relationships, practices, and technologies needed to build and design a home that is healthy and energy-efficient. For example, an examination of the relationship between airtightness, negative pressure differentials, and indoor air quality problems is part of the first tier.
The second tier presents the evidence and theory that support the broad framework, including formulas, precise definitions, construction details, and product information. The definitions of U-value, shading coefficients, and infiltration are examples of information that students often forget shortly after the end of the semester, but they need to understand the rationale behind the broad framework.
A local contractor and graduate of the class displays sample framing details he constructed to illustrate thermal defects.
Making It Exciting—Educational Tools and Techniques
The presentation of this information needs to be compelling. Education must be experiential and interactive to be effective, and I work hard to make classroom time as interesting and compelling as possible, using a variety of educational demonstrations, teaching tools, and guest speakers. These demonstrations are complemented by lots of background material, including videos and product information available in the college library. Some of the techniques I use to make theory more accessible to students are described below.
Diagnostic tools. I rely on a blower door, smoke pencil, digital manometer, hygrometer, infrared thermometer, and videos of thermographs to help me make the invisible visible. These diagnostic tools are excellent instructional aids because they let students “see” concepts that are often difficult to understand.
Framing details. Early in the semester when I am discussing thermal defects, a former student and local contractor brings a dozen constructed framing details into the classroom. This demonstration is superior to any handouts or sketches that can be drawn on a chalkboard.
Low-E demo. The best way to highlight the difference between a window with a high- and low-shading coefficient is with a hands-on demonstration. A local window distributor brings in a heat mirror demonstration, in which a heat lamp is set behind two windows with different coefficients, to demonstrate the tangible benefits of invisible low-E coatings.
Solar demonstration. To demonstrate the importance of window placement and solar orientation, I have built a sun machine based on a design in Norbert Lechner’s book, Heating, Cooling, and Lighting for Architects. This demonstration complements my lecture on passive solar design, which is based on the rules of thumb found in Passive Solar Strategies: Guidelines for Home Builders.
Multiple chemical sensitivity syndrome. Last semester I invited a level-headed young man who suffers from multiple chemical sensitivity syndrome to speak to my class, who made a far more compelling case for the need to take this issue seriously than I could have made myself. Healthy House Building, by John Bower, is an excellent resource on this subject (available from the Healthy House Institute and Amazon, along with an updated edition, Healthy House Building for the New Millennium).
Slides and overheads. I use more than 200 overheads and 400 slides to make the case for energy-efficient building and design. Slides of poor workmanship in the community, and accompanying anecdotes, really get students’ attention.
Videos. Videotapes can enhance a lecture or discussion. For example, since I don’t have access to a thermographic camera, I use a video of one to show what they can do. The Building for Performance Series and The Energy Conservatory videos are excellent.
Textbooks. The rapid evolution of our understanding of the indoor environment and home performance over the past four years has made it impossible to identify a current book for my students. I have been using the Residential Energy Design Construction Workbook by Ned Nisson as the class workbook. I supplement this book with photocopied chapters from Nisson’s and Dutt’s original text, The Superinsulated Home Book (which is available on Amazon). The latter book does an excellent job of covering the principles, while the former does a better job on construction and design details.
Product information. The college library now has a copy of the Energy Source Directory, a superb resource for locating products and equipment. I strongly encourage students to become familiar with it (from Iris Communications).
Workshops. Hands-on workshops are crucial to the course. Students participate in diagnostic work and tour an energy-efficient home under construction. Talking about blower-door testing and backdrafting never has the same impact that actually setting up a blower door does. Scheduling the construction site tour near the end of the semester provides an opportunity for students to synthesize what they have learned and to expand upon it. It also helps students to see an airtight duct system, transfer grilles, energy-efficient framing details, and ventilation systems. Seeing is believing—that’s what these workshops are all about.
The Measure of Success
A large turnout for the class does not equal success— the effectiveness of building-science education must be measured in the field. A course is only successful if its participants modify their approach to design and building in order to incorporate principles of energy efficiency. If builders and architects don’t respond to the course, then it needs to be evaluated and improved.
Marketing for the class is minimal, and most of the students find out about the class through an informal mix of word-of-mouth, my talks for contractors’ associations, or just from the course catalog. Some people who take the class have turned around and sent their employees through it. Last semester, I was pleased when 27 people enrolled in my class, but I am happier when I see the material covered in the course manifested in the field, as I often do. For the education to have been effective, the material must be reflected in designs and homes under construction. As I watch former students struggle with specifications, building details, cost control, and marketing, I continue to discover opportunities for improving the curriculum.
One of the biggest challenges facing the building-science community today lies in getting technology and building-science fundamentals to the people who need the information most—builders and architects. There is a significant amount of latent interest in building-science issues. Tapping this interest and effectively channeling it will be a tall order. Offering a building science class at the community college level is an important step toward getting technology into the hands of the people who can use it.
Read Alan Meier's editorial, “Learning Applied Building Science Is Still Hard to Do."
Answers to quiz:
- Quality construction.
- One Btu is the amount of energy it takes to raise the temperature of 1 pound of water 1° Fahrenheit.
- There are 100,000 Btu in a therm, and 3,413 Btu in a kilowatt.
- See the edition of Climatography of the United States for your state to determine local heating degree-days.
- Annual fuel utilization efficiency, which accounts for the effects of on/off cycling, flue losses and other fac- tors that affect furnace efficiency under actual operating conditions.
- Volatile organic compounds, a class of carbon-based chemicals that evaporate easily, thus giving off vapors that can be inhaled.
- Relative humidity, air temperature, velocity of air flow, and mean radiant temperature.
- Insulation voids, thermal bridging, convective loops in dropped soffits, air leakage through insulation, and air intrusion.
- The U-value, which is a measure of the number of Btu that will actually flow through a square foot of a given material in an hour for each degree of difference in temperature between either side of the material.
- The ASHRAE Standard 62-1989 Ventilation for Acceptable Indoor Air Quality suggests minimum ventilation rates for residential living areas of 0.35 air changes per hour (ach) of continuous fresh air based on volume of con- ditioned space, but not less than 15 cfm per person based on design occupancy.
- Shading coefficient, which is the ratio of total solar heat gain through a specific window, to the total solar heat gain through a single sheet of glass under the same set of conditions.
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