Energy-10: A New Look at an Old Friend

Last time Bion Howard covered software in Home Energy, he discussed a couple of new energy design software products that had recently come on the market (see "Two New Software Gems," HE Sept/Oct '99, p. 36). With the first appearance of this new column, which will run in the magazine on a regular basis, he takes a close look at an old favorite, Energy-10, which was developed by the National Renewable Energy Lab (NREL).

Software guru Bion Howard weighs in:

Energy-10 now claims more than 1,200 registered users. Preliminary results of the survey showed that, among architects, engineers, and energy analysts, the current version of Energy-10, Version 1.3, is being used primarily on residential and office buildings. The average building size is 10,000 ft², and the average energy savings estimated to be provided through using Energy-10 is 35%. Energy-10 appears to have a big user friendliness advantage over other EDS tools.

Version 1.3 was released in December 1999. Changes in this version address several nagging problems and incorporate many suggestions from the tool's large user base. Version 1.3 utilizes Typical Meteorological Year (TMY) data files that have been improved (now called TMY-2). For the sophisticated user, a utility program called Weathermaker allows customization of the data to reflect local conditions.

Version 1.3 also includes the following new features:

• A formerly preset building aspect ratio (ratio of width to depth) can now be changed.
• Minor bugs involving pollution coefficients and metric conversions have beencorrected.
• The number of windows allowed in daylighting simulations has been tripled.
• New and revised example exercises have been added.
• More informative titles are used in the RANK displays (these show data ranked inorder of priority).
• The help and how-to sections have been expanded.
• As a long-term user (and a project reviewer during the early stages of development), I can tell you that these updates smoothed out many of the rough edges of an already very useful program.

Schroeder was also excited to report that SBIC is planning to greatly expand its Web site to support building designers using Energy-10. For example, the council has created "NetForum," an on-line discussion group for users to share technical support questions and compare notes; this is located at www.crest.org/cgi-bin/netforum/psic-buildings/a/1. Another cool feature is a growing "frequently asked questions" (FAQ) page. Here, users can keep up with minor bugs, changes in features through various versions, and so forth. To view this page, go to www.sbicouncil.org/enTen/updates.html. For more on Energy-10, go to www.nrel.gov/buildings/energy10. Registered users can also download weather files from the SBIC or NREL Energy-10 Web sites.

--Bion Howard

Bion Howard is principal of Building Environmental Science & Technology (BEST), an environmental building consulting firm in the Washington, D.C. area.

Wanted Alive: Energy-10 Case Studies SBIC and NREL are looking for Energy-10 success stories that can be written and publicized. The building does not have to be constructed, but design drawings should be available. The purpose is to show how Energy-10 resulted in developing a superior building. Please call Doug Schroeder at (202)628-7400, Ext 210.

This new column in Home Energy will cover software tools for improving residential energy efficiency performance. It will also offer a dialogue on what readers hope to see in future energy design software programs and packages. Please feel free to write us with your thoughts on energy software and on what you would like this column to cover, as well as your specific questions on how best to utilize the software that you have. Send your e-mails to software@homeenergy.org.

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