Monday, January 23, 2012
Passive Solar Strategies
At this time of the year, when it’s cold outside but the days are getting longer, I think about passive solar strategies for reducing heating bills. The sun can provide heat for your school. Passive solar heating involves designing a building with south-facing windows and building overhangs so that the sun can heat in the winter but not the summer. Since the sun is higher in the sky in the summer than in the winter, those low-angle rays, in a properly designed building, will provide heat at this time of the year. When the sun’s angle is higher, during the warmer part of the year, a properly designed passive solar building’s roof overhangs will block the sun’s rays so no rays will strike directly on the glazing later in the year. For more information about using the sun to heat, follow this link: http://www.energysavers.gov/your_home/designing_remodeling/index.cfm/mytopic=10280 . Although it’s “home designing and remodeling” the explanation of the idea behind passive solar heating is the same as for schools.
The easiest passive solar strategy that reduces cooling bills is that of planting trees. Trees are often overlooked as an important passive solar cooling strategy, but it’s easy enough to incorporate deciduous trees into your landscaping. Plant deciduous trees on the southeast and southwest corners of your school. The trees provide shade during the seasons when they are leafed out, which is when cooling is needed. When the trees lose their leaves in the fall the sun shines on the school building, which provides passive solar heating if the building is designed for passive solar heat gain.
Another strategy is known as “indirect gain” (sometimes called a Trombe Wall) which uses a building’s mass to collect, absorb, then redistribute heat. The sun’s rays shine into a space between the building’s glazing and a masonry or concrete wall, which acts as a heat sink. Then various methods are used to move the heat into the rest of a building. http://www.energysavers.gov/your_home/designing_remodeling/index.cfm/mytopic=10300 .
I’ve discussed the use of daylight harvesting or daylighting in schools in a previous blog; check my blogs to see how to utilize this strategy to increase student health.
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As a professional architect who practiced in the design and construction of energy efficient building systems for over two decades I strongly support the integration and use of Passive Solar Strategies in the built environment. Having taken part in planning and designing of dozens of LEED certified projects I would like to emphasize a key component of passive solar strategies and design, which is the very culture of users.
ReplyDeleteAs important as providing these subtle and passive systems is the culture of users who use them day-in and day-out for the rest of their life-cycles. I cannot tell you how many instances I have witnessed where the owner, design, and construction teams spare no effort to implement various strategies, that actually get no use due to a host of different reasons.
It really does take a different culture to make use of the Passive Solar (and other) Strategies that are incorporated in our daily lives. It takes a higher level of sensitivity, a deeper level of understanding and concern for our own actions, as well as our impact on our immediate and overall environment. Without that kind of a genuine concern and care on the part of the user, even the best passive strategies go unutilized, taken offline like light-shelves that are used for books and pots.
Relatively few percentage of buidling users subscribe to this type of culture, certainly not all. Some by ignorance, some by choice. That's why I think it is so critically important to educate, and make everyone aware of the incremental difference that they can make through their own actions for the limited resources and environment. Old habits can be changed, new ones can be adopted only through a culture of understanding and care for these kinds of issues.
I know we are getting off topic, but I agree that if your idea is to be more energy-efficient in schools (while supporting a culture that implements and maintains energy-efficient methods and design), that this implementation needs to start at the educational level. If students (whatever grade) are instilled with this mindset in their educational institution, it could really help with the follow-through of projects related to passive solar strategies employed in schools. These projects can also serve as educational tools, both for analysis of the mechanisms and systems that make it work, as well as through the actual construction and maintenance of these systems in class work. I know that in middle school they often offer technology courses that deal with design and construction, in addition to woodshop and metal-working classes. These courses, as well as new courses related to home-built sustainable design systems, offer students the opportunity to be an integral part of implementing these increasingly important systems into their schools.
ReplyDeleteM. Bennett
Regional and Community Planning
Kansas State University
The concept of Passive Solar Strategies is definitely a product of an educational culture committed to stewardship of the environment. Judy Fosdick wrote an article for Whole Building Design Guide, “Passive Solar Heating” (2010), which stated “Passive solar heating systems do not have a high initial cost or long-term payback period, both of which are common with many active solar heating systems”. The benefits of passive solar heating necessitate building users (e.g., administrators, teachers, students) to be an instrumental influence to implement this design feature for new construction or major renovation. In addition, suggested benefits of passive solar heating are reaped by the occupants of the building, such as increased satisfaction and productivity (Fosdick, 2010).
ReplyDeleteH. Ortiz (Tarleton State University)
Fosdick, J. (2010). Passive Solar Heating. Retrieved from Whole Building Design Guide, A Program of the National Institute of Building Sciences: http://www.wbdg.org/resources/psheating.php