Consulting-Specifying Engineer - September 2007 - (Page 48)

As the kids gather their backpacks, notebooks and pencils for the new school year, MEP engineers are working tirelessly through issues of IAQ, energy efficiency and maintenance in their ongoing quests to design high quality, energy-efficient and cost-effective learning environments. And considering the fact that K-12 enrollment is expected to grow by 3 million—or 5.4%—between 2005 and 2014, according to the National Center for Education Statistics, Washington, D.C., there will be plenty of opportunities to offer innovative design solutions for what is considered to be the largest nonresidential U.S. building market, based upon construction value. Where to start? Being that the nature of classroom spaces is such that they must accommodate a high density of occupants—a typical classroom is between 900 sq. ft. and 1,500 sq. ft. with 22 to 35 kids—most classrooms require 900 cfm to 1,700 cfm of cooling airflow with 30% to 50% outside air requirements. “This high percentage of outside air has a high level of moisture content that must be dehumidified continuously or humidity levels will rise to unacceptable levels,” explains Brian Cumming, P.E., principal at BCA Consulting & Design Engineers, Maitland, Fla. “Prolonged exposure to humidity levels above 60% in a building can lead to mold and mildew growth, resulting in IAQ issues.” Terrance R. Liette, P.E., LEED AP, principal and executive director of engineering at Fanning Howey Engineering Group, Toledo, Ohio, concurs that IAQ ranks very high on schools’ lists of concerns. “Most school districts have had experiences with poor indoor air quality and, therefore, have high expectations for our approach to HVAC system design that will enhance the IAQ of a new or renovated facility.” While most A/C systems do a decent job of meeting heating and cooling requirements at full load, humidity buildup often can be an issue when the systems are only operating at part load because they usually respond only to temperature. “Most school districts have had experiences with poor indoor air quality and, therefore, have high expectations.” Consequently, Cumming, who has specialized in the K-12 market for the past 20 years, stresses, “The design engineer must carefully choose what type of system will dehumidify under all design conditions while minimizing energy consumption.” One approach Cumming recommends, especially in cases where energy consumption is more important than first cost, are the new static air-to-air heat exchangers that transfer both heat and moisture from the exhaust air to the outside air. “These heat exchangers media use new material technology, require little to no New LEED rating system for schools Expected to drive sustainable design for K-12 schools, the U.S. Green Building Council’s new LEED for Schools Rating System is geared for these facilities addressing issues such as classroom acoustics, master planning, mold prevention and environmental site assessment. Addressing the issue of first cost, a recent study by Capital E, a Washington D.C.-based consulting firm, “Greening America’s Schools: Costs and Benefits 2006,” concludes that it costs, on average, less than 2% or about $3 per sq. ft. more to build a green school than a conventional school—and the payback, from energy savings, comes within a year. “The LEED guide for schools is a good first step in the right direction. However, the budget restrictions that most school districts must face causes the real challenge for engineers,” points out Brian Cumming, P.E., principal at BCA Consulting & Design Engineers, Maitland, Fla. “While the LEED hype says it doesn’t cost that much more, some districts have found out the hard way that some of the LEED points can be very expensive and can add considerable cost to a project.” Martin Schmidt, P.E., LEED AP, mechanical engineer at The Schemmer Assocs., Omaha, Neb., agrees saying, “The development of LEED for Schools can only help raise the awareness of sustainable options; however, with the budgets that most school districts have to work with, it is questionable whether or not schools will actually pursue the accreditation.” At the same time, for those that can get over the budget issue, schools like the idea of teaching their students about the importance of environmentalism and sustainability through the built environment, not to mention having a building that is healthier and more comfortable for students and teachers. All in all, Cumming concludes, “Unlike previous energy conservation programs, I believe the LEED program will drive the trend toward budgeting and building schools considering the entire picture—learning, comfort, environment and conservation of natural resources.” For more information about the LEED for Schools Rating System, go to www.usgbc.org/LEED. 48 Consulting-Specifying Engineer • SEPTEMBER, 2007 Photography Courtesy of Fanning/Howey http://www.usgbc.org/LEED

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

For optimal viewing of this digital publication, please enable JavaScript and then refresh the page. If you would like to try to load the digital publication without using Flash Player detection, please click here.