Greenbriar East Elementary School Fairfax, Virginia

1. Greenbriar East Elementary SchoolFairfax, Virginia Michelle L. SianoMechanical OptionSpring 2005 Senior Thesis

2. Presentation Outline • Project Background • Current Mechanical System • Redesign Objectives • Mechanical Redesign • Daylighting Redesign • Conclusions • Acknowledgements • Questions

3. Greenbriar East Elementary SchoolProject Background • Location: Fairfax, Virginia • Site: 10 acres surrounded by residential neighborhoods • Building Size: • 59,000 sq. ft. renovation • 14,000 sq. ft. addition • Total of 73,000 sq. ft. when complete • Dates of Construction: • December 2003 - January 2006 • Construction Cost: $6.8 million

4. Project Team • Owner • Fairfax County Public Schools • Architect/Engineers • Hayes, Seay, Mattern and Mattern (HSMM) • General Contractor • Caldwell and Santmyer, Inc. HSMM

5. Presentation Outline • Project Background • Current Mechanical System • Redesign Objectives • Mechanical Redesign • Daylighting Redesign • Conclusions • Acknowledgements • Questions

6. Current Mechanical System • Classrooms • Served by a Dedicated Outdoor Air System (DOAS) with a Parallel Unit Ventilator System • 5 100% OA units ranging in size from 1,480 to 2,460 cfm

7. Current Mechanical System • Non-classroom spaces • Constant Volume System • Served by 7 rooftop units ranging in size from 1,750 to 8,050 cfm • Rooftop units provide full ventilation, heating, and cooling RA Space OA SA RTU

8. Current Mechanical SystemEvaluation • ASHRAE Standard 62-2001 • Required – 26,910 cfm • Designed – 16,110 cfm

9. Presentation Outline • Project Background • Current Mechanical System • Redesign Objectives • Mechanical Redesign • Daylighting Redesign • Conclusions • Acknowledgements • Questions

10. Redesign Objectives • Meet ASHRAE Standard 62 • Removes indoor air pollutants from the space • Results in better health among the occupants • Provide humidity control • Minimizes the potential for bacterial growth • Mold can trigger asthma attacks • Asthma has risen 49% since 1982 • Use energy efficient equipment to lower operating costs

11. Presentation Outline • Project Background • Current Mechanical System • Redesign Objectives • Mechanical Redesign • Daylighting Redesign • Conclusions • Acknowledgements • Questions

12. Mechanical Redesign Dedicated Outdoor Air System • Provides ventilation air and meets some of the thermal loads • Benefits • always meet ventilation requirements due to a lack of mixing • reduces amount of ventilation air • reduces duct and equipment sizes

13. Mechanical RedesignDOAS Equipment • Energy Recovery Units by Semco • EPHC Model - Enthalpy Wheel plus full heating and cooling • 8 units needed of approx. 3000 cfm • $33,000 - $39,000

14. Mechanical RedesignDOAS Equipment • Reduction in Coil Sizes 29% Reduction in Cooling Coil 46% Reduction in Heating Coil

15. Mechanical RedesignParallel System • Geothermal Heat Pumps • Dependent on large amounts of water or ground • Utilizes the constant temperature of the ground • Results in highly efficient system Refrigerant Loop HP HP Ground Loop

16. Mechanical RedesignParallel System • Console Units for Classroom spaces • Allows for reuse of current piping for refrigerant loop • Horizontal Ceiling units for non-classroom spaces • Serve multiple spaces Heat Pump

17. Mechanical RedesignParallel System • Ground Loop • Sized for 55.4 tons of heating vs. 52 tons of cooling • Typical Soil – 200-300 ft/ton • Sized based on 250 ft/ton  13,573 ft of ground pipe • Cost of $750/ton  $41,550 for piping and installation

18. Mechanical RedesignDOAS Savings

19. Mechanical RedesignDOAS Savings

20. Presentation Outline • Project Background • Current Mechanical System • Redesign Objectives • Mechanical Redesign • Daylighting Redesign • Conclusions • Acknowledgements • Questions

21. Basis for Evaluation

22. Daylighting Analysisfor Current Classroom • Average Illuminance • 2.94 fc • Maximum Illuminance • 41.8 fc • Minimum Illuminance • 0.3 fc

23. Classroom Redesign • Eight 2’ x 3’ windows at 5’ from finished floor

24. Daylighting Analysisfor Classroom Redesign • Average Illuminance • 12.86 fc • Maximum Illuminance • 33.5 fc • Minimum Illuminance • 0.7 fc

25. Presentation Outline • Project Background • Existing Conditions • Current Mechanical System • Redesign Objectives • Mechanical Redesign • Daylighting Redesign • Conclusions • Acknowledgements • Questions

26. Conclusions • DOAS • Reduced Ventilation Quantity by 33% • ERUs utilized enthalpy wheels to reduce heating and cooling loads • Geothermal Heat Pumps • Utilize the constant temperature of the ground for heating and cooling • Combination • Removes need for chiller • Saves $111,000 in energy use for chilled and hot water systems • Daylighting Redesign • Improved average illuminance to 12.86 fc

27. Presentation Outline • Project Background • Current Mechanical System • Redesign Objectives • Mechanical Redesign • Daylighting Redesign • Conclusions • Acknowledgements • Questions

28. Acknowledgements • AE Faculty and Staff • Dr. Freihaut • HSMM • Mike Kirkpatrick • Cortney Houghland • Fairfax County Public Schools • Dave Becker • My family, James, and friends

29. Presentation Outline • Project Background • Current Mechanical System • Redesign Objectives • Mechanical Redesign • Daylighting Redesign • Conclusions • Acknowledgements • Questions

30. Questions?