Johns Hopkins ospital Hospital N ew New Clinical Building Baltimore, MD

Transcription

1 Johns Hopkins Hospital New Clinical Building Baltimore, MD Dan Weiger ege 5 th Year CM

2 Agenda 1 Project Background 2 Chilled Beam Technology 3 Research Motivation 4 Cost & Schedule Impact 5 Conclusion 6 Questions

3 Project Background New Clinical Building Two Towers Adult and Children s with Connector 1.6 Million SF $573 Million GMP Oct Dec Design Bid Build, Fast Track Schedule Children s Tower Adult Tower Connector

4 Chilled Beam Technology Emerging Technology from Europe Few Projects in the U.S.A. SA Constitution Center in D.C. Yale Hospital Expansion in New Haven, CT Hospital Healthcare Trust # of Chilled Beams Year Consulting Engineer Royal Sussex, Bih Brighton Brighton & Sussex University i Hospitals Whichloe Macfarlane UCLH London University College 1, DSSR London Hospitals Beatson Oncology Greater Glasgow DSSR Health Board QMC Nottingham Nations Healthcare TB&A ACAD Hospitals, Greater Glasgow 1, DSSR Scotland Health Board Wakefield Mid Yorkshire Buro Happold Hospitals Hospitals Barts & Royal London The London 4, TB&A and DSSR

5 Chilled Beam Technology Two Types of Chilled Beams Passive Active 1. Primary Air 2. Nozzles 3. Room Air 4. Cooling Coil 5. Mixed Conditioned Air

6 Chilled Beam Technology Advantages Energy Efficient Space Savings Improved Comfort No Regular Maintenance Easy Commissioning

7 Chilled Beam Technology Disadvantages Possible Condensation Space Flexibility Increased Chilled Water Piping Increased Initial Cost of HVAC System

8 Research Motivation HVAC Accounts for 13.9% of Cost Largely on the Critical Path Campus Central Utility Plant Current VAV System with Reheat Coils Significant Impact from Changes

9 Research Motivation Goal: Demonstrate that a Chilled Beam HVAC System in non Invasive spaces has the potential to lower the cost (initial and life cycle) and accelerate the construction schedule. e

10 Only Applied to Non Invasive Spaces Primarily Office and Patient Rooms Sizing the System Extrapolate Results from Typical Areas Supply CFM on Drawings Used to Determine Design Loads

11 Sizing Example Cost & Schedule Impact Typ. Office Space on Level 6 6 Person Occupancy VAV Box S6D 1 1 Room is Served by VAV Total Supply = 300 CFM Room Temp = 70 F Supply Temp = 55 F VAV Box Supply pp y CFM

12 Sizing Example Continued 1. Total Sensible Design Load = 1.08 x Total Supply CFM x (Room Temp Supply Temp) = 1.08 x 300 CFM x (70 F - 55 F) = 4,860 BTU/hr 2. Ventilation i air required per ASHRAE is 25 CFM/person for patient rooms. Office spaces are not shown. To be on the conservative side, 25 CFM/person will be used for both the office and patient rooms. 3. Ventilation Air Required = 25 CFM/person x 6 persons = 150 CFM 4. Assume that ventilation air governs primary air supply right now and then check to see if it is greater than the latent load air requirement later. 5. Sensible Cooling Capacity of Primary Air = 1.08 x Vent. Air x (Room Temp Supply Temp) = 1.08 x 150 CFM x (70 F - 55 F) = 2,430 BTU/hr

13 Sizing Example Continued 6. Sensible Cooling by Chilled Beam = Total Sensible Load Sensible Capacity of Primary Air = 4,860 BTU/hr 2,430 BTU/hr = 2,430 BTU/hr 7. Latent load in the room can be approximated by the general rule of thumb that each person gives off 200 BTU/hr of latent load. 8. Latent Load = 200 BTU/hr/person x 6 person = 1,200 BTU/hr 9. Latent Cooling Capacity of Primary Air = 4,840 x Vent. Air CFM x (W Room W Primary ) = 4,840 x 150 CFM ( ) = 1,452 BTU/hr 10. The latent cooling capacity of primary air is greater than the latent load. Therefore, the ventilation air is adequate in supporting the latent load for the zone.

14 Sizing Example Continued 11. On average, a chilled beam can produce 1,000 BTU/hr/ft /f of sensible cooling capacity. 12. Chilled Beam Size = 2,430 BTU/hr 1,000 BTU/hr/ft = 2.43 ft Chilled Beam 3 ft Chilled Beam 13. Primary Air Reduction = 1 (Primary Air CFM Total Current Supply CFM) = 1 (150 CFM 300 CFM) = 50%

15 Cost Impact Add Deduct Cost Analysis Total Current HVAC Cost for ENTIRE Project Break down into Material and Labor Cost Total Current HVAC Cost for Non Invasive Spaces 60% of SF is Non Invasive Space 50% of HVAC Cost is for Non Invasive Space Analyze the Cost Impact of Each Line Item

16 Ductwork 75% Reduction in Primary Air 50% Savings in Material 30% Savings in Labor Cross Section =100 in 2 5 Cross Section =25 in 2

17 AHUs, Fans, Variable Frequency Drives 75% Reduction in Capacity 60% Savings in Material 40% Savings in Labor

18 Chilled and Heating Hot Water Piping 2 Pipe System in Interior Rooms (Cooling Only) 4 Pipe System on Exterior Rooms (Winter Heat) Analyzed Typical Space Assume At Least 1 Chilled Beam/Room 0.21 LF/SF of Chilled Water Piping Unit Pricing from Hot Water Piping Cost

19 Chilled Beam Units Substitute Chilled Beams for VAV Boxes and Diffusers Average Cost of Chilled Beam = $140/ft Average Cost of Installing Chilled Beam = $140/ft Office Rooms Patient Rooms Average VAV Boxes $0.61/SF $0.48/SF $0.55/SF Chilled Beams $4.16/SF $3.46/SF $3.81/SF % Increase 682% 721% 693%

20 Chilled Beam HVAC System Initial Cost Impact Other Cost Impacts Building Façade Structural Steel Extra Revenue Generated Energy Cost

21 Building Façade Cost Impact Critical Ceiling Plenum Clear Space 2 7 Reduce Clear Space by 50% Reduce Building Height by 1 4

22 Structural Steel Cost Impact Reduce Building Height by 1 4

23 Extra Revenue Generated by Space Savings 8,434 SF Savings in Mechanical Shafts 10,015 SF Savings in Mechanical Rooms

24 Energy Cost Impact Need Detail Energy Model to Accurately Predict Energy Savings Constitution Center Saved 23.8% Industry Experts Expect 20 35% 3 Scenarios 15%, 25%, 35%

25 Total Cost Impact Initial Cost Savings = $3,207,684 Total Yearly Revenue Generated = $18.2M Energy Savings 5 Year Savings = $1.5M $3.5M 10 Year Savings = $3.2M $7.5M 20 Year Savings = $7.6M $17.7M 30 Year Savings = $13.4M $31.3M

26 Schedule Impact Analyzed a Typical Floor Baseline Schedule Mechanical Overhead on Critical Path Piping has Significant Amount of Float

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28 Schedule Impact Install Duct Risers in Shafts Decrease by 30% Install Duct Mains Decrease by 30% Install HVAC Equipment Decrease by 40% Install Duct Branches Decrease by 30% Install OH CHW/RHHW/Steam Mains Delete Reheat Hot Water (RHHW) and add 275% Install OH CHW/RHHW/Steam RO Dlt Delete Reheat Hot Water and add 275% Install OH CHW/RHHW/Steam Connections Delete Reheat Hot Water and add 275% Install Grilles, Registers & Diffusers Delete and add Install Chilled Beams

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30 Conclusion Viable Alternative to VAV Could Have Taken Mech. System Off Critical Path Project Worked Well for Chilled Beams 48% of HVAC Cost was Ductwork Central Utility Plant Small Room Sizes = 1 Chilled Beam/Room High Energy Cost High Revenue per Area Many Assumptions More Research and Data Needed

31 Questions??? s