CHW Optimization Case Studies Presentation to: HESGNY CHW Optimization Case Studies NYUMED & MSKCC By WMGroup Engineers, P.C. May 14, 2009

Today’s Topics Discuss Case Histories of Chilled water system optimization for NYU MED and MSKCC Discuss NYSERDA funding programs for energy analysis and grants for implementations

Background Both NYU MED and MSKCC had multiple chiller plants Primary/Secondary and booster pumping Low Delta T Loss of chiller operating capacity

Background NYSERDA funding under FlexTech program provided opportunities to review the system and make recommendations for improvements NYSERDA provides 50% of the study costs directly to the engineer In both cases study recommended to create a virtual central system and converting primary/secondary/booster pumping system to variable volume primary pumping system

The additional benefit is fewer chillers required for operation Background The projected energy savings, implementation costs and NYSERDA grants are as follows: ITEM NYU MED MSKCC Pump HP Savings 1,300 1,600 Annual cost savings $460,000 $625,000 NYSERDA Grant $580,000 $598,000 Simple payback Less than 1 year 0.6 Years The additional benefit is fewer chillers required for operation

What is involved in Optimization study? Survey existing chiller plants and review System design Determine loads Create a hydraulic model of the system Evaluate pump head requirements Review compatibility of system components Evaluate system controls Recommend short term and long term system modifications

General Overview of NYUMC Chiller Plants

Summary of Main Chiller Plants

Main Chilled Water Distribution 12” Start of Distribution (Tisch Plant) End of Distribution * Drawing is not to scale (for illustration purposes only)

Site Chilled Water Distribution and Hydraulic Model

Hydraulic Analysis Measurements Plants were surveyed, pipe lengths were measured, and fittings were counted Distribution pipe lengths were estimated from satellite photos

Computerized Hydraulic Model Piping survey data and load estimates were entered into Pipe2006 software Model was run for multiple operating scenarios (newest plants operating, electric only, steam only, etc.) Program calculates flow and pressure distribution using the Darcy-Weisbach formula Output is dumped to a data file which must be evaluated with an Excel spreadsheet to interpret the results

Pipe2006 Software

Customized Excel Spreadsheets

Results of the Hydraulic Model Most of the distribution is sized properly Worst case pumping scenario is Smilow and Skirball at full load, Tisch offline. The only major bottleneck under these conditions is in the import line to Tisch where 5,600 gpm is being forced through a 12” line This may be alleviated in the future by adding an additional 12” line on supply (existing 12” Express Line on return would remain)

Current Distribution Bottleneck Current peak flow through the 12” distribution pipe is 5,600 gpm, with a head loss of 5.5 ft per 100’ Maximum pressure drop for good engineering practice is 2.5 ft per 100’, or 3,680 gpm

NYUMC Existing CHW system SMILOW TISCH SKIRBALL

NYUMC Modified CHW system SMILOW TISCH Bypass or removal of pumps Bypass or removal of pumps SKIRBALL Bypass or removal of pumps Bypass or removal of pumps

Tisch Plant Existing CHW Flow Diagram

Tisch Plant Modified CHW Flow Diagram Bypass or removal of pumps 20

Smilow Plant Modified CHW Flow Diagram Bypass or removal of pumps Bypass or removal of pumps 21

Skirball Plant Existing CHW Flow Diagram

Skirball Plant Modified CHW Flow Diagram Bypass or removal of pumps Bypass or removal of pumps Valves Closed Bypass NC 23

HCC Plant CHW Flow Diagram

Other Chiller Plants Coles contains a 280 ton steam chiller and MSB contains a 280 ton electric chiller, both of which should be decommissioned Coles and MSB loads should be served from the main distribution New 400 ton electric chiller in Tisch 7th floor should be kept to maintain redundancy for the Operating Rooms

Summary of Chiller Plant Recommendations Tisch, Smilow, and Skirball should all be converted to variable volume primary pumping Most of the loads will be taken up by Skirball and Smilow, with Tisch used to meet any peaking loads

Chiller Plants Operation

Chiller Plants Operation

Compatibility of Components

System Compatibility Mix of primary only, primary-secondary, and primary-booster pumping A single pumping method (variable volume primary only) must be selected to ensure compatibility between systems A consistent CHW supply and return temperature must be applied across the entire system (current plants have different ΔT’s) Large air handlers should be checked for the controls of cooling coils

Chilled Water System ΔT Tisch Plant is designed for 15°F ΔT Smilow Plant is designed for 12°F ΔT Many of the chilled water coils in the Medical Center are designed for 12°F ΔT Higher ΔT (and lower pumping energy) may be possible with careful control of chilled water coils

Pump Removals

Pumps to be Removed or Decommissioned Tisch PCHWP-1 100 hp Tisch PCHWP-2 100 hp Tisch PCHWP-3 100 hp Smilow P-5 100 hp Smilow P-6 100 hp Smilow P-7 100 hp Smilow P-11 75 hp Smilow P-12 75 hp Smilow P-14 25 hp Smilow P-15 25 hp Operating Room CHWP 20 hp Skirball P-35 100 hp Skirball P-36 100 hp Skirball P-37 100 hp HCC Data Center Pump 10 hp MSB CHW Pump 20 hp Coles CHW Pump 25 hp SLH CHW Pump 20 hp AHU-27 Pump 15 hp HCC P-4 40 hp HCC P-5 40 hp A total of 1,290 hp of pumps will be removed from service, reducing peak electrical demand by 962 kW

System Controls

System Controls All pumps must work together hydraulically All pumps should be controlled from a common differential pressure sensor located in the main distribution line Multiple differential pressure sensors should be installed on the main distribution to determine through experimentation the ideal one for control Optimum set-point for the pumps should be determined through experimentation

Executive Summary of Findings MSKCC

2. Total system Tertiary pump motor Hp = 531.5 Hp Chiller Plant Summary NOTE: 1. Total power values do not Include Standby pump power consumption values 2. Total system Tertiary pump motor Hp = 531.5 Hp

Chiller Plant Summary Loss of 650 Tons from Design point

MSKCC Existing CHW system Schwartz Bobst Memorial Zuckerman HX CH Haupt/OPB Howard CH HX CH Memorial 3rd Fl Rad/Onc CH Supply Rockefeller Not Connected to main system Return Haupt / Infill

MSKCC Modified CHW system Schwartz Bobst Memorial Zuckerman Bypass or removal of pumps HX Bypass or removal of pumps Bypass or removal of pumps CH Haupt/OPB Howard CH Rad/Onc HX Bypass or removal of pumps Bypass or removal of pumps CH Memorial 3rd Fl CH Bypass or removal of pumps Supply Rockefeller Connected to Main system Haupt / Infill Return

Summary A small first investment on your part of 50k to 70k will help you To save hundreds of thousands a year in operating costs Regain lost chiller operating capacity offsetting millions of dollars in future cost Reduce overall energy and help to make our planet Greener Contact any member of WM Group for a Free preliminary review of your system

The WMGroup Team Thank you