Consulting-Specifying Engineer - September 2007 - (Page 50)

maintenance and can cost $6 to $10 per cfm,” Cumming says. “First cost can be offset by reducing the capacity of the AC and heating equipment, and electrical gear serving that equipment—all of which reduce the equipment’s first cost.” Another HVAC strategy that Cumming finds useful for K-12 projects is the use of small packaged air-cooled chillers. “For renovations and additions to older schools, we like these small units using multi- ple scroll compressors with integrated pumps,” he explains. “These have a small footprint and good part-load efficiency with multiple, low cost and readily available compressors.” But when it comes to specifically dealing with IAQ and ventilation requirements, Martin Schmidt, P.E., LEED AP, mechanical engineer, The Schemmer Assocs., Omaha, Neb., recommends vertical, packaged ventilators designed to serve individual classrooms. “The ventilators allow designers to retrofit school classrooms to meet the current ventilation requirements and simplifies the installation by eliminating distribution ductwork from a central ventilation system,” he explains. “Its vertical configuration takes up a very small footprint in the classroom and allows it to be worked in with the cabinetry and shelving along the wall.” Through Liette’s holds extensive experience in the K-12 market with more than 400 projects nationwide under his belt, he has had much success with displacement ventilation systems. “Overall, this approach can result in reduced energy use and certainly has a positive impact on the indoor air quality of the classroom spaces,” he says. “There are several manufacturers that have taken very positive steps in the development of the displacement diffuser and the engineering calculations necessary to design an effective system.” Liette also considers geothermal systems as a potential design solution for schools, once a number of variables are evaluated. Although these systems have higher first cost and maintenance requirements, Liette emphasizes operational cost savings. Furthermore, he points out, “there are a number of high-efficiency heat pump manufacturers, so competition in the bidding environment is quite good, thus closing the gap a bit on bid day costing.” Along with energy conservation comes water conservation, more fully completing the sustainable picture, which more and more schools are striving to achieve. Consequently, K-12 designers are looking more seriously at products like waterless urinals. At the same time, it’s important to point out that even though retrofitting conventional urinals with no-water urinals leads to significant water conservation, “there is an Input #228 at csemag.com/quickResponse 50 Consulting-Specifying Engineer • SEPTEMBER, 2007 http://www.uecorp.com http://www.uecorp.com http://csemag.com/quickResponse

Table of Contents Feed for the Digital Edition of Consulting-Specifying Engineer - September 2007

Contents M/E Roundtable Cover Story: Airborne Superbugs Third-Party Liability Back to School Product Spotlight Codes & Standards Professional Practices How To New Products Jobs/Cliassifieds Specifier’s Notebook Pure Power Supplement New Technologies, Same Old Transmission Problems Wireless Battery Recharging Solar Concentration Renewables Tracking System A Mighty Wind The Importance of Load Bank Testing Quality Power for Security Systems

Consulting-Specifying Engineer - September 2007

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