Engineering by the inch

I remember a “Get Smart” TV episode where Maxwell Smart, in describing how a Chaos agent fell to his death while trying to jump from a building to moving truck, said, “Missed it by that much,” and used his pointer finger and thumb to indicate a very small space. If engineering isn’t that way, I don’t know what is.

By Michael Ivanovich, Editor-in-Chief April 1, 2008

I remember a “Get Smart” TV episode where Maxwell Smart, in describing how a Chaos agent fell to his death while trying to jump from a building to moving truck, said, “Missed it by that much,” and used his pointer finger and thumb to indicate a very small space. If engineering isn’t that way, I don’t know what is.

The article by David Sellers, PE, on page 27 about commissioning campus chilled water systems describes how elevations of cooling towers and piping systems can’t be off by “that much”—they must be precise for proper flow. Gravity is always in the wings, waiting to mess up a system if things aren’t just right. At risk are energy efficiency, noise and vibration, premature wear, and outright system failure. Keeping in mind how large cooling towers are, and how complex chilled water designs, specifications, and installations can be, it’s not uncommon for there to be flow problems when starting up a system. It’s good to see an article that describes the challenges and approaches to resolving them.

Sellers doesn’t say so, but it can be inferred from this article and his blog, “A Field Guide for Engineers” at www.csemag.com , that to get to the level of precision needed for large-system design, engineers need to get out into the field more and visit construction sites while their designs are being installed. By seeing how things are connected and at what phase of construction, along with talking to contractors, inspectors, and commissioning providers, designers will be more prepared for future designs.

The article also illuminates key differences among commissioning providers and services that are available today. Some owners opt to contract commissioning services before design completion, when making changes is least expensive, while others do not. Some owners opt to have commissioning providers witness construction; others just have commissioning providers become part of the paper-pushing process. While it’s easy to shrug this off as owners get what they pay for, poorly planned or insufficiently funded commissioning efforts are giving commissioning a bad rap.

But back to the matter of “that much.” In a totally different realm of engineering, William Sako describes the challenges of engineering and implementing mass notification systems for campuses on page 18. Sako asserts that no matter how well such systems are planned, events will occur and people will be hurt or killed. What matters is how fast and effective mass notification will be when an event occurs. The seconds or minutes it takes for alarms to go off and the accuracy with which people are directed to shelter or evacuation are where the proper engineering and implementation make a difference.

Finally, the article on radiant cooling by Geoff McDonell, PEng, on page 46, adds degrees to the margins engineers have to deal with. Many engineers are skeptical of radiant cooling systems because they are fearful of condensation problems. McDonell addresses that concern squarely in his article.

So rather than mess up a job by “that much,” we bring you articles and information that will help you stay squarely on your feet while jumping from one project to the next. Happy reading.

Send your questions and comments to: Michael.Ivanovich@reedbusiness.com