Eastern High School Baltimore, MD

1. Eastern High SchoolBaltimore, MD Patrick Dempsey Mechanical Option

2. ProjectBackground • Renovation: Historical Building • Multi-Use Owner/Tenant: Johns Hopkins • Project Team • General Contractor: The Whiting Turner Construction Co. • Architect: Kahn & Associates • MEP Consultant: Schlenger/Pitz & Associates • Structural Consultant: Skarda and Associates • Developer/Owner: Johns Hopkins(DOME Real Estate) • Cost: $22 million • MEP Cost: $6 million

3. Existing Mechanical System • Design Objectives • Lack of Basic Cooling System • Limit the Ductwork • Reserve as much tenant space as possible • Energy Recovery • Off Peak Air Conditioning: Ice Storage • Components • 4pipe chilled water/hot water system • 3 Weil McClain 588 Boilers(Fuel Oil fired) • 2 Carrier water cooled screw chillers • 2 Baltimore Air Coil Cooling Towers • 1 Ice Storage Tank

4. Existing Mechanical System (cont.) 3. System Characteristics • Ice Storage associated with lab/off peak space use • Shell perspective: limited tenant information

5. Mechanical Redesign • Redesign Objectives • Re-examine the loads/modeling • Lighting Loads > 2.0 W/sq.ft • Equipment Loads > 4.0 W/sq.ft • Remodel the space using HAP • Reduced the Peak Cooling Load • Focused on cooling system • Reduce the First Cost & Operating Cost • Size down the Equipment • Smaller Chillers: (211 ton < 246 ton) • Smaller Cooling Towers: (227 ton < 272 ton) • Less Ductwork • Down-sized AHU’s • Pre-Cooling • Adjusted Method of Off Peak Air Conditioning

6. First Cost Analysis • First Cost Existing: $ 1285453 • First Cost Redesign: $ 1012213 • Difference: $ 273240 Adjusted(Baltimore): $ 253294 • Savings garnered • AHU’s saved $ 72000 • Diffusers/Return Registers $ 80000 • Ductwork • 55000 lbs < 38000 lbs $ 95323

7. Annual Cost Analysis • HAP Calculations (HVAC components only) • Baltimore Gas & Electric Rates • Existing Annual Cost • $ 104245 per year for HVAC costs • Redesign Annual Cost • $ 89710 per year • Differential • $ 14535 per year • Lifecycle Cost • Duration = 15 years • Nominal Interest Rate = 5% • $150868 saved (Present Value)

8. Pre-Cooling • Methodology: Dr. Braun • Cool the structure during off peak hours • Float the temperature • Control oriented • Building Candidacy • Significant Structure for thermal storage: Thick Walls • Utility Rate that penalizes peak usage • Mechanical system comfortable with off peak air conditioning • Modeling • Thermostat based ideally • Setpoints • 68 degrees Fahrenheit(unoccupied morning cooling) • 75 degrees (occupied cooling) • Issues: limited setpoints, temperature profiles • Not feasible • EQUEST • HAP

9. Pre-Cooling Continued • How to model the pre-cooling effect • Utility Based: Trying to Prove Annual Cost savings • Peak shifts to the morning then scales back up in the afternoon • Compare to the Ice Storage Setup • Load profiling • HAP thermostat schedules are limited to 2 setpoints • HAP loading schedules can stagger the load as a percentage on an hourly basis • Simulate the peak shifts using 3 load inputs • Occupancy • Lighting • Equipment • Keep the profiles close to equal(area under the curve) • Adjusted the throttling range(float)

10. Ice Storage Profile

11. Pre-Cooling Profile

12. Load Profiling Results • Annual Cost Analysis(HVAC components only) • Annual Cost of Redesign(Ice Storage): $89710 • Annual Cost of Pre-Cooling System: $84915 • Differential: $ 4795 • Primary Area of Reduction: Cooling • Air Fans, Heating, Pumps, Tower Fans: neglible total diff. • Lifecycle Cost • Duration= 15 years • Nominal Interest Rate = 5% • $ 49853 saved (Present Value)

13. Mechanical Redesign Summary • Remodeled building with lowered electrical loads • Resized equipment using newer model saving roughly a quarter of a million dollars in first cost and saving roughly $15000 annually. • Instituted a pre-cooling controlled system taking advantage of the existing off peak air conditioning apparatus. • Pre-cooling saved nearly $5000 annually. • Comparison between original system and smaller pre-cooled system results in nearly $20000 in annual savings. • All savings were tabulated for HVAC costs only.

14. Electrical Impact • Reduced lighting loads led to drastic reductions in the Non-HVAC annual cost • Existing Original System Component Costs • Lighting: $ 229807 • Equipment: $ 171315 • Ratios are off • Equipment Reduction would be justifiable but the reduction in peak load was overly generous

15. Electrical Impact Redesign • Redesign Reduced Annual Cost • Original Lighting Cost: $229807 • Redesign Lighting Cost: $ 59499 • Differential: $170358 • Distribution • Roughly $175000 Equipment Cost • 4.0 Watts/sq.ft • Savings support reduced loads • Existing Annual Cost: $401122 • Redesign: $236032 • Differential: $165090 • Illusory • Reduced lighting actual loading • Supports the rationale for reduction

16. Schedule Impact • Smaller Mechanical System = Shorter Schedule • Major Components • Air Handling Units • Original Schedule: 25 days • New Schedule: 17.5 days • Ductwork • Original Schedule: 194 days • New Schedule: 133 days • Diffusers & Return Registers • Original Schedule: 114 days • New Schedule: 78 days • Chillers & Towers: no real savings • Difference: 104.5 days • Conservatively: 74.5 days saved.

17. Conclusions • Reduced MEP First Cost by roughly 20% • Saved $15000 annually just by reducing the lighting loads to accepted levels • Saved another $5000 annually through pre-cooling • Supported my reduced lighting loads by examining the annual costs of the electrical equipment • Achieved a massive reduction in schedule, conservatively reduced to nearly 75 days

18. Acknowledgements Thanks to: • My sponsor, Jimmy Cachola, of Schlenger/Pitz • Penn State AE Faculty • Especially Dr. Mumma, Dr. Srebric, Dr. Freihaut, and Prof. Ling • Prof. Parfitt & Jonathan Dougherty • Special thanks to my thesis advisor: Dr. Bahnfleth • Fellow AE’s • Jason Borowski, Katie McGimpsey, Brad Cordek, Nicole Renno • Family & Friends • Any that I may have left out

19. Questions?