CURBING THE COST OF DATA CENTER COOLING. Charles B. Kensky, PE, LEED AP BD+C, CEA Executive Vice President Bala Consulting Engineers

Transcription

1 CURBING THE COST OF DATA CENTER COOLING Charles B. Kensky, PE, LEED AP BD+C, CEA Executive Vice President Bala Consulting Engineers

2 OVERVIEW Compare Cooling Strategies in Free- Standing and In-Building Data Centers Consider the Role of Portable Spot Cooling Learn How Changes in IT Equipment and Racks can affect Cooling Needs Increasing Cooling Efficiency

3 SINGLE BUILDING VS. IN-BUILDING Building Height is a Factor Single Bldg. is < 4 Stories dedicated to Data Center In-Building is Bldg. with a Data Center in it. Can be any height. Single Building Total Cooling Flexibility Dx, Water Cooled, CHW Free Cooling Airside Economizer Waterside Economizer Adiabatic Cooling System Type Flexibility Access Floor In Row Containment Overhead Duct Pumped Refrigerant (load dependent) In-Building Cooling Plant limited by building height, location and existing infrastructure Floor to Floor height limits type of system Typically Water Cooled or Chilled Water

4 Free Cooling Air Side Direct Air Exchange T RH F I L T E R T RH Data Center Greatest Energy Savings Longer Free Cooling Periods Humidity Control Key Not Ideal for All Climates Sensible & Latent Capacity IT IT

5 Free Cooling Air Side Heat Exchanger T RH Data Center T RH Sensible Capacity Only Slightly Less Energy Savings Slightly Shorter Free Cooling Periods Slightly More $$ IT IT

6 Free Cooling Air Side Energy Wheel Data Center F I L T E R Sensible & Latent Capacity Slightly Less Energy Savings Slightly Shorter Free Cooling Periods IT More $$ IT

7 Free Cooling Water Side Glycol/Dry-Cooler Moderate Free Cooling Periods Slightly More Fan Energy at CRAC Sensible & Latent Capacity Smaller Tonnages

8 Free Cooling Water Side Air Cooled Chiller Moderate Free Cooling Periods Less Fan Energy than Glycol/Dry Cooler Sensible & Latent Capacity Larger Tonnages Limited Manufacturers Available CRAC

9 Free Cooling Water Side With Heat Exchanger CRAC Better Free Cooling Periods Freezing of CT is Key Sensible & Latent Capacity Less Fan Energy than Glycol/Dry Cooler Larger Tonnages More Water Treatment Required

10 Adiabatic Cooling Free Cooling Reduced Refrigerant Usage Combo Mode Great for Dry Climates Extends Free Cooling Period Comparable to Cooling Tower System High Water Treatment $$

11 IN-ROW COOLING Cooling Unit Cold Air Chamber

12 IN-ROW COOLING Rear Door Heat Exchange (RDHX) P C R A C Piping can be over cabinets or under floor Room Temperature & Humidity Conditioning

13 ROW BASED COOLING No Access Floor Required Cascade Effect Reduced Reduced Fan Energy Provides T+RH Control Redundancy Moderate Challenge Free Cooling Available Cooling Unit w/ Chilled Water Units More Units Required VFDs Adjust Airflows to IT Loads (energy savings) IT Changes Challenging Cold Aisle Service Required In Every Row Hot Aisle

14 WHY CONTAINMENT?

15 CONTAINMENT Comes in All Different Configurations

16 CONTAINMENT Hot Aisle Provides Room Conditioning Provides Ride-Through Capacity During Failure IT Staff Work in Hot Zone Easier for Free Cooling Applications (hot air is captured) Cold Aisle Room is Hot Limited Ride-Through in Failure

17 HOT CONTAINMENT Vertical Exhaust Ducts (Chimneys) Easier to Retrofit on Legacy Data Centers Rear Cabinet Doors Must be Sealed Airflow Differential Pressure Should be Studied Same Performance as Hot Aisle Containment

18 CLOSE COUPLED COOLING Overhead in the Rows Flexible Configurations Redundancy Moderate Challenge (Interlaced) Requires Min. IT Loads Higher Efficiency due to Supply Air Temps & Reduced Fan Energy Reduced Cascade Effect Free Cooling Available Room Conditioning (T+RH) or Supplement Cooling for HD Areas

19 Pumped Refrigerant Summer Operation Free Cooling Outdoor Ambient 95 F 70% Load 24.1 Check Valve Condenser Solenoid Valve Refrigerant Pumps OFF Check Valve Electronic expansion valve Evaporator Circuit 2 Circuit 1 Compressors ON Check Valve

20 Partial Economization Fall/Spring/Evening Operation Pumped Refrigerant Outdoor Ambient 65 F 70% Load 15.1 Check Valve ON Condenser Solenoid Valve OFF Refrigerant Pump Check Valve ON Electronic expansion valve Evaporator Circuit 2 Circuit 1 Compressor OFF Check Valve

21 Full Economization Winter Operation Pumped Refrigerant Outdoor Ambient 25 F 70% Load 3.7 Check Valve ON Condenser ON Solenoid Valve Electronic expansion valve Refrigerant Pump Moderate Free Cooling Periods Less Fan & Pump Energy than Glycol/Dry Cooler & Chiller Options Sensible & Latent Capacity Evaporator Limited Manufacturers Available Circuit 2 Circuit 1 Check Valve OFF Compressor OFF Check Valve

22 SYSTEM TYPES IT Load Determines System Type: Lower Densities (10kW/cabinet) CRAC (underfloor) Overhead Distribution Higher Densities (15kW-25kW/cabinet) In Row Pumped Refrigerant Contained Cabinet Door Cooled Combined with CRACs Extreme Density (25+kW/cabinet) CRAC Underfloor Spread out cabinets throughout the Data Center Adjacent Cabinets should be Lower Density Supplemental Cooling

23 PORTABLE SPOT COOLING VS. LOCALIZED Portable Spot Cooling Temporary Provision ONLY! Sudden Addition of IT Equipment Band-aid for Cooling System Failure Placed at Point of Urgent Need (typically air-cooled Dx) Localized Cooling Planned Redundancy Reliable More Efficient (heat rejection) Not Portable, but Delivered Directly to added IT Load In Row Overhead Supplemental Cooling Contained Cabinet

24 IT EQUIPMENT CHANGES Current IT equipment more tolerant of higher server inlet temps and humidity

25 ASHRAE CHART ASHRAE Recommended (2004) 59DP Inlet Server Conditions Allows Longer Free Cooling Hours Reduces Humidification Needs & Water Usage Improves Mechanical Equip. Efficiency ASHRAE Allowable 62.6DP 41.9DP ASHRAE Recommended (2008 TC9.9)

26 IT EQUIPMENT CHANGES Increased cabinet depth and width allows more airflow in cabinet Taller cabinets add more IT equipment and airflow space Perforated Cabinet Doors VS. Solid Cabinet Doors Improved cable management can eliminate need for articulating cable arms (air dams) Virtual servers can run at higher utilization and require more cooling and power Fiber Channel over Ethernet VS. UTP Cabling reduces power consumption and increases bandwidths (FCoE avg. 9 Watts/port vs. Traditional Ethernet avg.17 Watts/port). More uniform air flow configuration through the server (front-side, side-back, front-back)

27 SUMMARY Cooling Efficiency Tips Hot/Cold Aisle Containment Free Cooling ( Air or Water) Air Delivery (don t over CFM) Chase the Cold Spots Increase Supply Air Temperatures Lower Humidity Set Points Balance Air Flows and Pressure Localized Cooling Reduces Fan Horsepower

28 Contact Us at