Benefits of. Air Flow Management. Data Center

Transcription

1 Benefits of Passive Air Flow Management in the Data Center

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3 Learning Objectives At the end of this program, participants will be able to: Readily identify if opportunities i where networking equipment performance could be maximized through the introduction of passive air flow management for side vented equipment in racks or cabinets Identify five steps that can be taken to enhance CRAC efficiency in a flooded data center environment Examine the cooling performance of a flooded ddata center and compare the cooling efficiency of that data center environment as passive air control solutions have been installed Analyze the incremental improvements in data center air flow management and how that translate into energy savings through CFD analysis

4 Power Consumption on the Rise in Data Centers Demand for higher density in the rack Average: 20 servers per rack by 2010 Up 50% from 2002 The Rack is drawing more power than ever Average kw per rack 2000: 1kW 2006: 6-8kW 2010: 20kW+ for many large data centers Source: IDC - The Impact of Power and Cooling on Data Center Infrastructure 4

5 Demands On Networks Today Virtualization Convergence Consolidation Cloud Computing High-bandwidth applications Streaming video Digital medical records Social media

6 It s Hot in Here! Heat Exhaust & Equipment Failure Heat exhaust Raises ambient temperature Creates hot spots Can cause equipment failure Increases cooling costs Electrical cooling can add to the load

7 Passive Cooling at the Network Equipment Rack or Cabinet Cisco Nexus and Catalyst Cooling Considerations Racks and Cabinets passive airflow management Baffle system maintains efficient cold-aisle/hot-aisle airflow, ifl providing maximum cooling for side-vented equipment Reduces risk of equipment failure from overheating by passive removal of extra heat generated by switch fans Cisco Nexus 7018 in Server Rack

8 Infrastructure Management Designs that Positively Impact Airflow

9 9 Flooded Data Center Data Center with Air Flow Management

10 Enhance Energy Efficiency True passive thermal management Cold air should only go where it is needed Prevent hot and cold airflow from mixing Hot air should return as hot as possible Isolate, redirect airflow from side vented equipment Network equipment airflow is unobstructed Cooling without fans

11 Fact: Flood cooling is the most common approach to data center cooling Associated issues: Lower than necessary temperature set points Higher than required humidity set points Poor airflow requires fans to run more often Cold return air to CRAC intake reduces efficiency Wasted rack space

12 It s Hot in Here! ASHRAE guidelines have just changed recommended operating temperatures in a data center. 20 C 26.7C 21.1C 23.9C ASHRAE TC 9.9, 2011

13 Containment design lowers energy costs for cooling Data center managers can save 4% in energy costs for every degree of upward change in the ambient ttemperature. t - Mark Monroe, Director of Sustainable Computing at Sun Microsystems What is your set-point today? (the higher the temperature set-point the greater the potential savings) 13

14 Hot or Cold Aisle Containment? Use the natural properties of airflow Cold air requires containment Hot air naturally rises Both hot air and cold air must be managed 14

15 Reasons the cooling system may not be efficient Cold air pumped into raised floor not rising through perforated tiles Mixing of hot and cold air through spaces in racks and cabinets CRAC units pulling in cold air instead of hot Too many obstacles for good airflow

16 Air Flow Control address: Subfloor pressure balancing and cable cutout management Elimination of cabinet level cool air loss Loss of cooling air from cold aisle areas Return air mixing with cooling air Loss of cooling air to cold aisle and isolated equipment Baseline 9000 Sq. Ft. Data Center The air patterns show areas where hot air is mixing with the cold supply air

17 CRACs: Cooling & Temperatures Rack Statistics: Only 11 of the 105 racks are within the ASHRAE standard for intake temperatures Range of Max Inlet Temp Number of Racks Above 80 F 5 Between 75 F and 80 F 11 Between 70 F and 75 F 27 Below 70 F 62 5 are above the standard d 89 are below the standard

18 Step One Control the supply airflow The goal is to have CFM per floor tile in the cold aisle Two impediments to desired air flow 1. An imbalance of subfloor air pressure 2. Subfloor plenum is leaking cold supply air into the room

19 Step Two Prevent supply air from flowing through the equipment racks Stop hot exhaust air from recirculating into the equipment intake With blanking panels

20 The Results From blocking raised floor openings, disrupting air velocity, and adding blanking panels in unused rack and cabinet space

21 CRACs: Cooling & Temperatures Rack Cooling Statistics: 1 rack is within the ASHRAE standard for intake temperatures; the rest are lower Range of Max Inlet Temp Number of Racks (Before changes) Number of Racks (After changes) Above 80 F 5 0 Between 75 F and 80 F 11 1 Between 70 F and 75 F 27 4 Below 70 F

22 Step Three Partition hot and cold aisles above the racks Two cold aisles contained by using solutions such as Vinyl Panels and Vinyl Strip Doors The separation enabled the shut off of one 22T CRAC unit! Note: Proper design of containment solution does not limit the use of overhead cable routing which can be a problem when using permanent devices like ducts or chimneys. Air Curtains

23 CRACs: Cooling & Temperatures Rack Statistics: The results of all 3 steps All racks are between the 70 F and 80 F range Name Airflow Return Temp Supply Temp Cooling (Tonnage) Cooling (kw) CRAC 1 13, CRAC 1_1 1 Turned off CRAC 3 10, CRAC 1_2 13, CRAC 3_1 10, Cooling capacity efficiency increased enough to turn one CRAC unit off while maintaining the same level l of cooling.

24 Step Four Direct hot exhaust air to the AC coil through the drop ceiling void Prevent mixture of hot and cold air by funneling exhaust directly into the drop ceiling void Increase CRAC efficiency Raise set point 10 F Air Extension

25 The Results Air Plugs, Air Disrupters, Air Blanking Panels, Air Curtains and Air Extension Before After

26 Isolated equipment Step five addresses lost cooling efficiency in the isolated equipment areas. These p g y q p areas are not laid out in a hot / cold aisle configuration.

27 Step Five Complete containment Supply S l air coming from the subfloor bubbles out like a water fountain Air spills in all four directions Three walls are needed to hold, or pool, the supply air so that its only direction is through the IT equipment Air Booth

28 The Results Air Plugs, Air Disrupters, Air Blanking Panels, Air Curtains, Air Extensions and the Air Booth Our model shows that with Our model shows that with full containment, including isolated equipment, two CRAC units can be shut off

29 CRACs: Cooling & Temperatures Rack Statistics: The results of all 5 steps All racks are still between the 70 F and 80 F range Name Airflow Return Supply Cooling Temp Temp (Ton) Cooling (kw) CRAC 1 13, CRAC 1_ 1 Turned off CRAC 3 10, CRAC 1_2 Turned off CRAC 3_1 10, Two 22T CRAC units have been shut off Huge increase in cooling capacity of the three CRAC units

30 Enhance Energy Efficiency True passive thermal management Prevent hot and cold airflow from mixing i Isolate, redirect airflow from side vented equipment Network equipment airflow is unobstructed Cooling without fans

31 Thank you!

32 Cooling Capacity Mechanical engineers have long seen the underutilization of the AC equipment due to low temperature and high humidity air return. Where a 30 ton unit will only supply 23 tons of cooling. Containment of supply and return airflow will greatly increase cooling capacity of your AC units. Then a 30 ton unit can produce 46 tons of cooling! Containment keeps the hot return air isolated so that the temperature of the return air at the CRAC is higher. Hotter return air will greatly increase the Hotter return air will greatly increase the AC cooling capacity.