The Hearst Tower 959 Eighth Avenue New York

The Hearst Tower 959 Eighth Avenue New York, NY Jessica Lucas Mechanical Option

The Hearst Tower New York, NY Presentation Outline Introduction Background u Background Current System u Current System Proposed System u Proposed System Cost Analysis u Cost Analysis Electrical Breadth u Electrical Breadth Structural Breadth u Structural Breadth Conclusions u Conclusions Jessica Lucas Mechanical Option

The Hearst Tower New York, NY Site and Location Located along 8 th Avenue between 56 th & 57 th Street in Midtown Manhattan ü Introduction Background u Current System u Proposed System u Cost Analysis u Electrical Breadth u Structural Breadth u Conclusions Constructed through the center of the original Hearst Headquarters (1928) Landmark building will be hollowed with new Tower constructed through center Jessica Lucas Mechanical Option

The Hearst Tower New York, NY Project Team ü Introduction Background u Current System u Proposed System u Cost Analysis u Electrical Breadth u Structural Breadth u Conclusions Building Owner: Hearst Corporation Architect: Foster and Partners Associate Architect: Adamson Associates MEP: Flack+Kurtz CM: Turner Construction Jessica Lucas Mechanical Option

The Hearst Tower New York, NY Size and Architecture • 42 stories ü Introduction Background • 856, 000 SF • 2000 Hearst Employees Architectural Program • Open Office u Current System u Proposed System u Cost Analysis • Auditorium • Test Kitchens • Television Studio u Electrical Breadth Most notable features: u Structural Breadth • Diagrid Facade u Conclusions • LEED Gold certification Jessica Lucas Mechanical Option

The Hearst Tower New York, NY Existing Mechanical System ü Introduction ü Background Current System u Proposed System u Cost Analysis Central Chilled Water Plant serving a low temperature Variable Air Volume system Waterside System • 4 -1000 ton cooling towers on roof level • 2 -1200 ton & 1 -400 ton electric chillers in basement chiller plant Airside System • 4 -110, 000 CFM AHU’s, serve office tower • Indoor Design Conditions u Electrical Breadth u Structural Breadth • 75 F for cooling/50% RH cooling u Conclusions • 70 F for heating • Air supplied to spaces at 45 F Jessica Lucas Mechanical Option

The Hearst Tower New York, NY Proposed Mechanical System: ü Introduction ü Background ü Current System Proposed System u Cost Analysis u Electrical Breadth u Structural Breadth u Conclusions Combining Steam Driven Absorption Cooling with a Dedicated Outdoor Air/ Radiant Floor System Replace electric chillers with double effect steam driven absorption Replace the central VAV AHU’s with dedicated outdoor air (DOAS) units Install radiant floors to parallel DOAS for both heating & cooling Jessica Lucas Mechanical Option

The Hearst Tower New York, NY Goals of Proposed System ü Introduction ü Background ü Current System Proposed System u Cost Analysis u Electrical Breadth u Structural Breadth u Conclusions • Ensure ASHRAE Std. 62. 1 -2004 compliance • Obtain the LEED point for IAQ • Lessen the Tower’s dependence on an overextended electric grid • Lower annual operating cost • Meet the original criteria to create a reliable Class “A” office building Jessica Lucas Mechanical Option

The Hearst Tower New York, NY Proposed Mechanical System: Dedicated Outdoor Air System (DOAS) ü Introduction ü Background ü Current System Proposed System u Cost Analysis u Electrical Breadth u Structural Breadth u Conclusions What is DOAS? • 100% OA unit based on ASHRAE Std. 62. 1 • Decouples Sensible & Latent Loads • Utilizes Energy Recovery DOAS for Hearst: • Std. 62. 1 +30% OA for IAQ LEED point • Utilize an Enthalpy Wheel for total energy recovery • Maintain 45 F supply air temperature Jessica Lucas Mechanical Option

The Hearst Tower New York, NY Proposed Mechanical System: ü Introduction ü Background ü Current System Proposed System u Cost Analysis u Electrical Breadth u Structural Breadth u Conclusions The resulting DOAS Design: • 3 -40, 000 CFM Semco units with a molecular sieve desiccant coated enthalpy wheel • Chiller plant downsized by 30% • • Cooling coil load decreased from 44 tons to 10. 5 tons Supply Air at 45 F and saturation Jessica Lucas Mechanical Option

The Hearst Tower New York, NY Proposed Mechanical System: Radiant Floor Heating and Cooling ü Introduction ü Background ü Current System Optimize layout based on daylighting study using AGI 32 software Proposed System u Cost Analysis u Electrical Breadth u Structural Breadth u Conclusions Jessica Lucas Mechanical Option

The Hearst Tower New York, NY Proposed Mechanical System: Absorption Chillers 3 -600 ton Double-effect chillers arranged in parallel ü Introduction ü Background Lithium Bromide/Water- no CFC’s or HCFC’s ü Current System New chiller plant requires 60 k. W of electric input, compared to 1, 941 k. W used in the electric chiller plant Proposed System u Cost Analysis u Electrical Breadth u Structural Breadth u Conclusions Con Edison offers incentives for steam driven cooling during the cooling season Jessica Lucas Mechanical Option

The Hearst Tower New York, NY Proposed Mechanical System: Additional Alternative ü Introduction ü Background ü Current System Proposed System u Cost Analysis u Electrical Breadth u Structural Breadth u Conclusions Can I save even more with an Electric Chiller Plant w/DOAS System? • Still 30% reduction in chiller plant size • Still only minimum CFM • Higher COP with vapor compression cycle Jessica Lucas Mechanical Option

The Hearst Tower New York, NY Proposed Mechanical System: Cost Analysis ü Introduction ü Background ü Current System ü Proposed System Cost Analysis u Electrical Breadth u Structural Breadth u Conclusions Electric w/VAV Electric w/DOAS Absorption w/DOAS Total Electricity Total Steam $93. 1 M $41. 2 M $33. 9 M $31 M $29. 4 M $39. 4 M Total O&M $25. 6 M $14. 5 M $15. 9 M 20 year LCC $156. 4 M $93. 4 M $98. 8 M Jessica Lucas Mechanical Option

The Hearst Tower New York, NY Proposed Mechanical System: Mechanical Summary Electric/DOAS ü Introduction ü Background ü Current System ü Proposed System Cost Analysis u Electrical Breadth u Structural Breadth u Conclusions • Lowest LCC • Lowest Operating Cost • Higher COP However… • Still dependent on electric grid • Black-outs = diminished reliability Recommendation: Absorption/DOAS Radiant Jessica Lucas Mechanical Option

The Hearst Tower New York, NY Electrical System Breadth Current Electrical System: ü Introduction • 4 -4000 amp service take-offs ü Background • ü Current System Each takeoff is served by 1 -6000 amp service switch ü Proposed System ü Cost Analysis Electrical Breadth u Structural Breadth u Conclusions • Each takeoff provides 480/277 V 3 phase service from primary transformers Daylighting & Occupancy sensors used throughout for energy conservation High efficiency ballasts, helped obtain rebates from NYSERDA Jessica Lucas Mechanical Option

The Hearst Tower New York, NY Electrical System Breadth Existing Chiller Plant ü Introduction ü Background ü Current System ü Proposed System ü Cost Analysis Electrical Breadth Chiller 1&2: 2000 A fuses, 6 sets of 3 - 400 MCM with 1 -#3/0 ground in 3”conduit Chiller 3: 800 A fuse, 2 sets of 3 -500 MCM with #2/0 ground in 3. 5” conduit Cost of wiring & conduit: $932. 00/LF New Plant u Structural Breadth Chiller 1, 2, 3: 40 A fuses, 1 set of 3 -#6 with 1#10 ground in 1”conduit u Conclusions Cost of wiring & conduit: $46. 80/LF Jessica Lucas Mechanical Option 1 -

The Hearst Tower New York, NY Electrical System Breadth Existing VAV System ü Introduction 8 supply fans- 124 FLA ü Background 4 return fans- 65 FLA MCC total connected load of 1, 697 FLA ü Current System ü Proposed System ü Cost Analysis Electrical Breadth u Structural Breadth u Conclusions Proposed DOAS System 3 supply fans- 77 FLA 3 return fans- 65 FLA MCC total connected load of 632 FLA Jessica Lucas Mechanical Option

The Hearst Tower New York, NY Electrical System Breadth: Conclusions ü Introduction Downsizing equipment results in: ü Background First cost savings for wire & conduits ü Current System ü Proposed System ü Cost Analysis Decreased switch sizes Increased distribution board space Allows for easier installation Electrical Breadth u Structural Breadth u Conclusions Jessica Lucas Mechanical Option

The Hearst Tower New York, NY Structural System Breadth: Current System ü Introduction ü Background ü Current System ü Proposed System ü Cost Analysis ü Electrical Breadth Structural Breadth u Conclusions Half of the foundation is supported by spread footings, half by caissons Primary lateral support provided by the perimeter Diagrid Secondary lateral system defined by braced frame at the service core Structure below 10 th floor uses a mega-column system to support a large unbraced height Jessica Lucas Mechanical Option

The Hearst Tower New York, NY Structural System Breadth: Effect of Radiant Floors ü Introduction ü Background ü Current System ü Proposed System ü Cost Analysis ü Electrical Breadth Structural Breadth u Conclusions • International Fire Code 2003 2 hour fire rating • Vulcraft Deck 6” slab • Radiant tubes 1. 5” concrete cover • Check deck, beams, girders with additional concrete load • LRFD Manual example for Composite W-shape flexural member design (unshored construction) Jessica Lucas Mechanical Option

The Hearst Tower New York, NY Structural System Breadth: Conclusion ü Introduction ü Background ü Current System ü Proposed System ü Cost Analysis ü Electrical Breadth Structural Breadth u Allowable Shear Stud Capacity greater than Maximum shear under applied loading Vu < ΣQn i. e. 42. 8 k < 451 k Allowable Flexural Capacity exceeds Maximum moment under the applied factored loading Mu < ФMn i. e. 428 ft-k < 450 ft-k No changes needed to member sizes! Conclusions Jessica Lucas Mechanical Option

The Hearst Tower New York, NY Conclusions Proposed mechanical system satisfied criteria set forth at the beginning of the design process: ü Introduction Lower annual operating costs ü Background ü Current System Lessen dependence on electric grid ü Proposed System Increase reliability ü Cost Analysis Maintain Class “A” market status ü Electrical Breadth ü Structural Breadth Positively impact electrical system by lowering first cost & allowing for easier installation u Conclusions No nominal impact on Structural system Obtain LEED point for IAQ Jessica Lucas Mechanical Option

The Hearst Tower New York, NY Acknowledgements A huge Thank You to: ü Introduction ü Background ü Current System ü Proposed System ü Cost Analysis ü Electrical Breadth ü Structural Breadth ü Conclusions JJ, Dr. Freihaut, Dr. Bahnfleth, Dr. Mumma, Dr. Srebric and the rest of the AE Faculty. My fellow classmates especially Jenny, Jayme, Yulien, Dave, Bryan, and Adam. Paul Reitz of Flack+Kurtz Jessica Lucas Mechanical Option

The Hearst Tower New York, NY ü Introduction ü Background ü Current System ü Proposed System ü Cost Analysis ü Electrical Breadth ü Structural Breadth ü Conclusions Questions? ? Jessica Lucas Mechanical Option