Consulting-Specifying Engineer - December 2007 - (Page 26) Table 1 - Energy usage, design versus budget End use Electrical receptacles Lighting Space cooling Fans/pumps Design case (kWh) 19,740 29,823 42,168 9,717 Budget case (kWh) 19,740 48,232 116,703 110,028 Table 2 - Energy management system data on energy use Date 07/15/2006 07/15/2007 Receptacles 40 x 106 W 88 x 106 W First floor 6 x 106 W 17 x 106 W Second floor 6 x 106 W 18 x 106 W A/C 44 x 106 W 83.5 x 106 W Electrical efficiencies “Our new building consumes so much less electricity than our previous building that the electrical savings alone will pay for the cost of the new building in 10 to 15 years at today’s electricity rates,” said Juan S. Quintana, president of Standard Refrig- eration. Strategies employed in this project yielded the results for electricity usage shown in Table 1. Using the LEED-NC Version 2.1 criteria, where receptacles are not considered, the electricity savings is in excess of 70% when compared with ASHRAE 90.1-1999. The building management system of the new facility, along with a separate energy monitoring system, provided the electricity use data shown in Table 2. For the period from July 15, 2006, to July 15, 2007, the results of a comparison between design and actual use are shown in Table 3. The hours of use and the square footage used in the model defined the difference in design vs. actual use of electricity for the receptacles. The complete building area should have been used in design for the receptacles rather than the air conditioned areas. The building receptacles serve refrigerators, water coolers, vending machines, uninterruptible power supplies, photocopiers, and other electrical units that consume electricity 24 hours per day. • For receptacles design: 12,000 sq. ft x 2,496 h x 0.66 W/sq. ft = 19,768 kWh High school makes the lifecycle grade inard Junior High School’s design almost makes you want to go back to school just to check out the building. The facility incorporates thermal advanced insulating systems, daylighting, lighting controls, and geoexchange heat pump technology with exhaust air heat recovery ventilation systems. A building automation system monitors and controls engineered systems throughout the 117,000-sq.-ft building. “Poudre School District (PSD) is very sensitive to total lifetime cost impacts of the design, construction, operation, and maintenance requirements, keeping in mind the total lifecycle costs rather than focusing primarily on the lowest first costs,” said Eric Young, PE, president of EMC Engineers Inc. and lead mechanical engineer on the project. This was the fourth project that project architect, RB+B Architects, Fort Collins, Colo., designed under PSD sustainability guidelines. EMC was selected to provide three separate areas of service for this project: energy analysis, mechanical design, and commissioning. PSD selected EMC’s energy team to help establish energy and sustainable goals for the facility, to create an energy model, and to update the model and advise the design team throughout the design process as relevant architectural and MEP systems features were determined. EMC also was selected for its experience in designing high-performance geoexchange systems. Finally, the firm was responsible for co-commissioning the building, working closely with Architectural Energy Corp., Boulder, Colo. The district challenged the design team not only to explore ways to make this project even more energy efficient than previous schools, but also to make it exceptionally easy to build and maintain. “The budget for the entire project was $17.45 million and the build- K Kinard Junior High School Fort Collins, Colo. MEP Engineer: EMC Engineers Inc., Lakewood, Colo. Bronze Winner ing was completed for a total cost of $17.5 million,” Young said. “The cost of the mechanical and plumbing portions of the project, including the geoexchange borefield, was $2.2 million, It came in on budget, equaling $18.86/sq. ft, a very competitive construction cost for this type of system.” PSD documented the energy performance of this school for one complete year from July 2006 through June 2007, and tracked its performance against another conventional, similar-sized junior high school in the district. Electrical and gas savings can be summarized by the amount of energy used in one year per square foot for each school: Kinnard’s 24.8 kBtu/sq. ft/yr compared to 55 kBtu/sq. ft/yr for the other school—an energy cost savings of approximately $30,000 in the first year of operation. Stu Reeve, energy manager for PSD, echoes the excitement in the performance results. “Based on previous high-performance schools in PSD, we increased our expectations and performance goals for this project and EMC exceeded them all,” Reeve said. 26 Consulting-Specifying Engineer • DECEMBER 2007 Photography courtesy of EMC Engineers Inc.
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