The Cost of Using 1970’s Era Design Concepts and “FEAR”in Chilled Water Systems WM Group Engineers, P.C. Presented By: Hemant Mehta, P.E.

What is the “FEAR” No change in design as previous design had no complains from client –No complain because no bench mark exists –Fear to take the first step to change the concepts to use state of the art technology –Consultants sell time. Fear is any new concept will take lots of time and it is not worth the effort

What are1970’s Era Design Concepts? System Design for Peak load only Primary/Secondary/Tertiary Pumping 5°C (42°F) supply temperature System Balancing Circuit Setters Band Aid solution for any Problem Projected Demand way above reality Oversized chiller, pumps TDH and everything else to cover behind

State of the Art Plant concepts Plant designed for optimum operation for the year. Peak hours are less than 200 hours a year Variable flow primary pumping system 3.3°C (38°F) or lower supply temperature No System Balancing. Balancing is for a static system. No Delta P valves – No Circuit Setters No Band Aid solution for any Problem Use chilled water system diversity (0.63) to Project Cooling Demand The total Chilled water pumping TDH even for a very large system should not be more 63 meters(than 200 feet)

Selecting Equipment to Optimize Efficiency Chiller equipment is often erroneously selected based on peak load efficiency. Peak load only occurs for a small number of hours of the year, as shown on the load duration curve below:

The Design of the Human Body Heart (Variable Volume Primary Pump) Lungs (Chillers) Brain (Building End-Users)

Basic 1970’s Era Chiller Plant Design Primary Pump Secondary Pump Decoupler Line Building Loads Chiller

Current Design Used on Many Large District Chilled Water Systems Primary Pump Secondary Pump Decoupler Line Building Loads Chiller Energy Transfer Station Building Pump

Modern Variable Volume Primary Chiller Plant Design Building Loads Chiller Variable Speed Primary Pump

Lost Chiller Capacity Due to Poor ΔT 5°C (41°F) No Flow Through Decoupler 13°C (55.5°F) 5°C (41°F) 13°C (55.5°F) 150 L/sec (2,400 gpm) 150 L/sec (2,400 gpm) 150 L/sec (2,400 gpm) 150 L/sec (2,400 gpm) Chiller sees a ΔT of 8°C (14.5°F) at a flow of 150 L/sec (2,400 gpm) The chiller capacity is therefore 5,000 kW (1,450 tons) Ideal Design Conditions

Lost Chiller Capacity Due to Poor ΔT 5°C (41°F) 9°C (48.25°F) 5°C (41°F) 13°C (55.5°F) 75 L/sec (1,200 gpm) 150 L/sec (2,400 gpm) 75 L/sec (1,200 gpm) 150 L/sec (2,400 gpm) Chiller sees a ΔT of 4°C (7.25°F) at a flow of 150 L/sec (2,400 gpm) The chiller capacity is therefore 2,500 kW (725 tons) Case 1: Mixing Through Decoupler Line 75 L/sec (1,200 gpm) at 5°C (41°F)

Lost Chiller Capacity Due to Poor ΔT 5°C (41°F) No Flow Through Decoupler 5°C (41°F) 150 L/sec (2,400 gpm) 150 L/sec (2,400 gpm) 150 L/sec (2,400 gpm) 150 L/sec (2,400 gpm) Case 2: Poor Building Return Temperature Chiller sees a ΔT of 4°C (7.25°F) at a flow of 150 L/sec (2,400 gpm) The chiller capacity is therefore 2,500 kW (725 tons) 9°C (48.25°F)

Small Loss in ΔT Rapidly Reduces Chiller Capacity System ΔTChiller Capacity 8.0°C (14.4°F)100% 7.5°C (13.5°F)94% 7.0°C (12.6°F)88% 6.5°C (11.7°F)81% 6.0°C (10.8°F)75% 5.5°C (9.9°F)69% 5.0°C (9.0°F)63% 4.5°C (8.1°F)56% 4.0°C (7.2°F)50% Assuming a design ΔT of 8°C (14.4°F):

Technical Paper by Erwin Hanson (Pioneer in Chilled Water System Design) 8°C 9°C 11°C

Billing Algorithm for Buildings to Give Incentive to Owners to Improve ΔT Adjusted Demand Cost Adjusted Consumption Cost Total Cost = Demand + Consumption Total Site Demand Cost X Bldg ton-hrs Total ton-hrs X Cost Penalty Factor Total Site Electric Cost - Total Adjusted Bldg Demand Cost X Bldg ton-hrs Total ton-hrs

The Design of the Human Body Heart (Variable Volume Primary Pump) Lungs (Chillers) Brain (Building End-Users)

History of Variable Primary Flow Projects King Saud University - Riyadh (1977) Louisville Medical Center (1984) Yale University(1988) Harvard University (1990) MIT(1993) Amgen (2001) New York-Presbyterian Hospital (2002) Pennsylvania State Capitol Complex (2005) Duke University (2006) NYU Medical Center (2007) Memorial Sloan-Kettering Cancer Center (2007)

King Saud University – Riyadh (1977) 60,000 ton capacity with 30,000 tons for first phase Six 5,000 ton Carrier DA chillers Seven 10,000 GPM 240 TDH constant speed pumps Major Problem: Too much head on chilled water pumps Lesson Learned: Be realistic in predicting growth

Louisville Medical Center (1984) Existing system (1984) –Primary/Secondary/Tertiary with 13,000 ton capacity Current System (2007) –120 feet TDH constant speed primary pumps with building booster pumps – 30,000 ton capacity –Changed the heads on some of the evaporator shells to change number of passes –Primary pumps are turned OFF during winter, Early Spring and Late Fall. Building booster pumps are operated to maintain flow.

Yale University (1988) Existing system (1988) – Primary/Secondary/Tertiary with 10,500 ton capacity Current System (2007) –180 feet TDH VFD / Steam Turbine driven variable flow primary pumps – 25,000 ton capacity –Changed the heads on some of the evaporator shells to change number of passes

Amgen (2001) Creation of a computerized hydraulic model of the existing chilled water plant and distribution system Identification of bottlenecks in system flow Evaluation of existing capacity for present and future loads Two plants interconnected: Single plant operation for most of the year, second plant used for peaking Annual Energy Cost Savings: $500,000

Additional Variable Primary Flow Projects Harvard University (1990) MIT(1993) New York-Presbyterian Hospital (2002) Pennsylvania State Capitol Complex (2005) Duke University (2006) NYU Medical Center (2007) Memorial Sloan-Kettering Cancer Center (2007)

CCWP-1 plant was built four years ago CCWP-2 design was 90% complete (Primary/Secondary pumping) We were retained by Duke to peer review the design Peer review was time sensitive Plant design for CCWP-2 was modified to Variable Primary pumping based on our recommendations Duke University Background

Duke CCWP-1 Before

Duke CCWP-1 After Dark blue pipe replaces old primary pumps

Duke CIEMAS Building CHW System 90% closed Triple duty valves 50% closed

Balancing valve 50% closed Duke CIEMAS Building AHU-9

NYU Medical Center (2007) Plant survey and hydraulic model indicated unnecessary pumps 1,300 horsepower of pumps are being removed, including 11 pumps in two brand new chiller plants $300,000 implementation cost $460,000 annual energy savings

NYU Medical Center (2007) Plant survey and hydraulic model indicated unnecessary pumps 1,300 horsepower of pumps are being removed, including 11 pumps in two brand new chiller plants $300,000 implementation cost $460,000 annual energy savings 3 Pumps Removed 7 Pumps Removed 8 Pumps Removed 3 Pumps Removed

Memorial Sloan-Kettering - Before

Memorial Sloan-Kettering - After Bypass or removal of pumps Bypass or removal of pump

Pump Cemetery To date we have removed several hundred large pumps from our clients’ chilled water systems

Plant Capacity Analysis -Detailed System Analysis is a Necessity Modern computer software allows more complex modeling of system loads, which has proven to be very valuable to optimize performance and minimize cost. Return on investment to the client for detailed analysis is typically very high.

Applied revolutionary control logic New York Presbyterian Hospital Log Data ~ 20  F  T

Bristol-Myers Squibb Biochemistry research building 140,000 square feet AHU-1 (applied new control logic) 100,000CFM AHU-2 (existing control logic remained) 100,000 CFM

Bristol-Myers Squibb Applied revolutionary control logic

PA State Capitol Complex – CHW ΔT

South Nassau Hospital – CHW ΔT

Good Engineers Always Ask “Why?” Why does the industry keep installing Primary/Secondary systems? Why don’t we get the desired system ΔT? Why does the industry allow mixing of supply and return water?

Good Engineers Always Ask “Why?” Why does the industry keep installing Primary/Secondary systems? Why don’t we get the desired system ΔT? Why does the industry allow mixing of supply and return water? Answer: To keep consultants like us busy! Why change?

Reasons to Change The technology has changed Chiller manufacturing industry supports the concepts of Variable Primary Flow Evaporator flow can vary over a large range Precise controls provides high Delta T

Change is Starting Around the World Most of the large district cooling plants in Dubai currently use Primary/Secondary pumping By educating the client we were able to convince them that this is not necessary We are now currently designing three 40,000 ton chiller plants in Abu Dhabi using Variable Primary Flow as part of a $6.9 billion development project

Summary There are many chilled water plants with significant opportunities for improvement WM Group has a proven record of providing smart solutions that work We will be happy to review your plant logs with no obligation 1985: $ 0.171/ton-hr 2002: $0.096/ton-hr

Thank You Hemant Mehta, P.E. President WM Group Engineers, P.C. (646)

September 16, 2008 The New Royal Project Central Energy Plant Study By

Determine the Optimum Central Energy Plant Configuration and Cogeneration Feasibility Project Objective

A new tertiary hospital for the region 95,000 m 2 initial area (basis of analysis) Disaster Recovery Consideration N+1 Onsite Power Generation (+/- 70% of peak demand) Two separate central plants The New Royal Project

Project Site

Typical Utility Tunnel

Developing load profiles for Heating, Cooling and Power Developing and screening of Options Creating a computer model for energy cost estimate Performing Lifecycle Cost Analysis Performing Sensitivity Analysis Conclusions Study Approach

Cooling/Heating – Daily peaks provided by Bassett Cooling:7,400 kWt (2,100 RT) Heating:8,000 kWt Power – Daily peaks provided by Bassett Peak demand: 4,500 kWe Min. demand:1,400 kWe Load Profiles

Cooling Loads

Daily Cooling Load Profile

3-D Cooling Load Profile

Cooling Load Duration Curve 607 Equivalent Full-Load Hours

Heating Loads

Daily Heating Load Profile

3-D Heating Load Profile

Heating Load Duration Curve 1,742 Equivalent Full-Load Hours

Electric Loads

Daily Electrical Load Profile

3-D Electrical Load Profile

Natural Gas:$9.00 / GJ Electricity (taken from hospital bill): Demand Charge: $ per kVA per day Based on contracted annual demand About $10.00 per kW per month Energy Charge: $ / kWh (on-peak, 7 am to 10 pm) $ / kWh (off-peak, 10 pm to 7 am and weekends) Fixed Charges: $ per day About $830 per month Utility Rates

Minimum first cost Two locations Conventional equipment Electric chillers Gas-fired boilers Diesel emergency generators No cogeneration or thermal storage Operational efficiency and reliability Base Option Considerations

Central Energy Plant – Base Option Plant Component East CEPWest CEP Chiller Plant (2) 2,500 kWt electric motor driven, water-cooled chillers Boiler Plant (2) 2,750 kWt fire tube boilers producing hot water Thermal Storage None Power Generation (1) 2,000 kVA diesel generator (emergency power)

Non-Electric Chillers Absorption Chillers (with or without heaters) Steam Turbine Driven Chillers Gas Engine Driven Chillers Thermal Storage Ice Storage Chilled Water Storage Cogeneration Geothermal Alternative Plant Considerations

Electric vs. Non-Electric Chillers Sample taken from another project

Hybrid Plant – Option 1A Plant Component East CEPWest CEP Chiller Plant (1) 2,650 kWt electric motor driven, water-cooled chiller (1) 2,450 kWt direct-fired absorption chiller/heater (1) 2,650 kWt electric motor driven, water-cooled chiller (1) 2,450 kWt direct-fired absorption chiller/heater Boiler Plant (2) 1,750 kWt fire tube boilers producing hot water (1) 1,500 kWt direct-fired absorption chiller/heater (same unit as above) (2) 1,750 kWt fire tube boilers producing hot water (1) 1,500 kWt direct-fired absorption chiller/heater (same unit as above) Thermal Storage None Power Generation (1) 2,000 kVA diesel generator (emergency power)

Advantages of ice storage Ice storage requires less space Suitable for low temperature operation Disadvantages of ice storage Ice generation requires more energy Ice storage system has a higher first cost Ice storage is not considered for this project Ice Storage vs. Chilled Water Storage

Thermal Storage – Option 2 Plant Component East CEPWest CEP Chiller Plant (2) 1,750 kWt electric motor driven, water-cooled chillers Boiler Plant (2) 2,750 kWt fire tube boilers producing hot water Thermal Storage (1) 30,000 kWt-hr chilled water storage tank connected to site chilled water distribution system Power Generation (1) 2,000 kVA diesel generator (emergency power)

Cogeneration Alternatives SystemApplication Assessment Reciprocating EnginesSuitable for high electric but low thermal loads such as NRP. Fuel CellsEmerging technology not for commercial use. MicroturbinesLimited capacity of units and requires skilled labor. High Pressure Steam Boiler and Back Pressure Turbine No steam required by NRP. High Pressure Steam Boiler and Condensing Turbine No steam required by NRP. Gas Turbine with HRSG Typically for larger installations, requires skilled operators, and possible emissions treatment issues. Combined Cycle Generation Typically for larger installations, requires skilled operators, and possible emissions treatment issues.

Engine Generator Topping Cycle

Option 3 – Cogen w/ Gas Engines Plant Component East CEPWest CEP Chiller Plant (2) 1,750 kWt electric motor driven, water-cooled chillers (1) 1,140 kWt hot water-fired absorption chiller (2) 1,750 kWt electric motor driven, water-cooled chillers (1) 1,140 kWt hot water-fired absorption chiller Boiler Plant (2) 1,750 kWt fire tube boilers producing hot water Thermal Storage None Power Generation (1) 2,000 kVA natural gas generator (cogeneration) (1) 2,000 kVA diesel generator (emergency power) (1) 2,000 kVA natural gas generator (cogeneration) (1) 2,000 kVA diesel generator (emergency power) * Diesel generators not required if onsite LNG storage is provided

Option 4 – Cogen & Thermal Storage Plant Component East CEPWest CEP Chiller Plant (2) 1,750 kWt electric motor driven, water-cooled chillers (1) 1,140 kWt hot water-fired absorption chiller (2) 1,750 kWt electric motor driven, water-cooled chillers (1) 1,140 kWt hot water-fired absorption chiller Boiler Plant (2) 1,750 kWt fire tube boilers producing hot water Thermal Storage (1) 10,000 kWt-hr chilled water storage tank connected to site chilled water distribution system Power Generation (1) 2,000 kVA natural gas generator (cogeneration) (1) 2,000 kVA diesel generator (emergency power) (1) 2,000 kVA natural gas generator (cogeneration) (1) 2,000 kVA diesel generator (emergency power) * Diesel generators not required if onsite LNG storage is provided

Summary of Options OptionChiller PlantBoiler PlantThermal Storage Power Generation 1 (4) 2,500 kWt electric(4) 2,750 kWt boilersNone (2) 2,000 kVA diesel backup generators 1A (2) 2,650 kWt electric, (2) 2,450 kWt absorbers (4) 1,750 kWt boilers, (2) 1,500 kWt absorbers None (2) 2,000 kVA diesel backup generators 2 (4) 1,750 kWt electric(4) 2,750 kWt boilers (1) 30,000 kWt-hr chilled water storage (2) 2,000 kVA diesel backup generators 3 (4) 1,750 kWt electric, (2) 1,140 kWt absorbers (4) 1,750 kWt boilersNone (2) 2,000 kVA natural gas cogen units, (2) 2,000 kVA diesel backup generators 4 (4) 1,750 kWt electric, (2) 1,140 kWt absorbers (4) 1,750 kWt boilers (1) 10,000 kWt-hr chilled water storage (2) 2,000 kVA natural gas cogen units, (2) 2,000 kVA diesel backup generators

Simulation of plant operation Calculation of total energy use (power and fuel) and cost Energy Model

Hourly Computer Model

Detailed Equipment Data

Monthly Energy Cost Summary

Monthly Energy Cost Graphs

Comparison of Annual Energy Costs $4.3 M $4.2 M $3.0 M

Thermal Storage Economics Installed Cost (Opt. 1A):$1,700,000 Annual Energy Savings: $98,000 Simple Payback: 17 years Low cooling load reduces benefits of thermal storage

25-Year Lifecycle Cost Analysis Capital Cost Energy Cost (gas and electric) Maintenance and Consumables Cost Staffing Cost Economic Rates Discount Rate

Construction Cost Estimates

Project Cost Factors Based on typical healthcare development projects Preliminaries and Margin:23% Project Contingency:15% Cost Escalation to Start Date:15% Consultant Fees:10% Total multiplier is approximately 1.8

Comparison of Initial Costs

Maintenance and Staffing Costs OptionAnnual Maintenance CostAnnual Staffing Cost 1$84,000$130,000 1A$90,000$130,000 2$86,000$130,000 3$105,000$195,000 4$107,000$195,000 Options 3 and 4 also require a $240,000 engine overhaul every 5 years (included in analysis) Staffing cost based on $65,000 per year for each full-time staff employee

Economic Parameters Based on estimated government rates Discount Rate:8.00% Gas Cost Escalation Rate:4.30% Electric Cost Escalation Rate:3.40% Maintenance Escalation Rate:4.00% Consumables Escalation Rate:4.00%

25-Year Lifecycle Cost Analysis

Cost Summary OptionFirst Cost Annual Energy Cost 25-Year Present Worth Cost 1$20,839,000$4,345,000$87,223,000 1A$22,879,000$4,311,000$88,825,000 2$23,558,000$4,243,000$88,473,000 3$32,176,000$2,988,000$83,303,000 4$33,704,000$2,978,000$84,722,000

Results of Lifecycle Cost Analysis

Sensitivity Analysis Varying electric demand charge Varying gas cost Change economic parameters Carbon emission tax Use of geothermal energy

Thank You Hemant Mehta, P.E. President WM Group Engineers, P.C. (646)