A Green Approach. Thermal

Transcription

1 A Green Approach to Thermal Management

2 Thermal Management - AGENDA Definitions & Thermal Facts Density Trends Rack Level Management Passive Solutions Thermal Sources & Green Solutions Data Center Layout Recommendations High Density Close-Coupled Solutions Efficiency Metrics

3 Heat & Cold HEAT: A form of energy (enthalpy) that acts on substances to raise their temperatures, Sensible Heat Heat that t causes a change in temperature of a substance Latent Heat Heat energy absorbed in process of changing the form of a substance without changing temperature or pressure COLD: The ABSENCE of heat Cold is not a `Thing as is heat and can not be `Made When something is cold, it just has less heat than something else or sometime else. Cold is the result of removing heat

4 Basic Facts 1 Watt of power consumed = 1 Watt of heat 100% of power used is converted to heat Heat will seek cold before it rises Common to cool the room, to cool the equipment Average data center has 2.7 times more AC than equipment needs Water removes heat 3467 times more efficiently than air Static pressure drops with one open floor tile

5 Current Trends within Data Centers 83% of data centers have Power or Heat problems Annual costs in the millions just for cooling Power density is increasing an average of 15-20% per year and has doubled in the last three years Average server power densities have increased 10 times in the last 10 years Under current efficiency trends the energy consumption of servers and data centers will nearly double by 2011 Your data center may not be able to accommodate new equipment because of power, cooling capacity or space limitations Your data center may have thermal hot-spots that cause system reliability issues Designs must ensure precision cooling

6 Data Center Manager Concerns 83% of DC Managers have Power / Heat Concerns Power 12% Cooling 21% Both 38% Suspect Both/Don t Track 12% Neither are Problems Now 17% What are they doing about it? Ran more power 44% Add more cooling 33% Stopped Buying / Consolidated 28% Changed Hot/Cold Layout 25% Increased Size of Data Center 23% Source: AMD

7 Increased Density Driving Data Center Changes Moore s Law: Chip density will double every 18 months 40 year trend of increasing clock speeds slowing New designs incorporate multiple processors Dual-Core & Quad-Core chips Dual Core chips initially consumed 130 watts Pat Gelsinger (Intel) predicts dozens of cores

8 Servers in use: Server Deployment 2U & 3U 31% (Stable) 1U 29% (Growing) 4U & 5U 17% (Declining) Blades 14% (Growing) Other 14% (Declining) Average Un-Used Rack Space = 18% Blade servers are the biggest driver of the heat demand within an enclosure IDC forecast that the cost of the server will be outweighed by the cost of running the cooling to support it by 2011 Source: AMD

9 IT Hardware Longevity Negatively Impacted by Overheating IT hardware reliability dramatically reduced d For every 18 F (10 C) increase in ambient temp long-term hardware reliability 20 is reduced by 50% 15 (Arrhenius Theory) 10 Significant problem for equipment at the top of cabinets Capacitor life is shortened by temperature CPU Operating Lif fe (yrs) Temperature ( C) Source: AMD

10 Power and cooling requirement can be #1 and #2 cost for operating a data center Cost of Cooling "In some cases, power & cooling costs account for 40-50% of the total data center operation budget" (Intel)

11 Four Levels of Thermal Challenges

12 Thermal Challenges for Data Centers Predict future cooling requirement for the data center Optimize layout and placement of new hardware capacity planning Optimize i internal rack configurations OBJECTIVE: Lower the components operating temperature Efficiently!

13 R k L l Th l M t Rack Level Thermal Management Changing the Approach

14 Improving Airflow Through The Cabinet The cabinet is a critical element of the data center cooling system Positioning of active hardware impacts component cooling The configuration of the cabinet must facilitate front-to-back airflow through equipment Prevent or limit the mixing of the hot exhaust air with the conditioned supply air Limit space where air can circulate between een & around Active Components

15 Rack Level Thermal Management Recirculation Internal Bypass Over top Through neighbor Proper Configuration Blanking Panels Door Perforation Source: Optimizing data centers for high-density computing HP technology brief, 2 nd edition

16 Thermal Cloud Cool air is heavier than warm air Static pressure may not be enough to reach to top of cabinets

17 Test Bed Case 1: Input Parameters Industry Standard d Server Cabinet Number of servers = 5 Total power (heat) dissipated in servers = kw Total airflow through servers = 1,580 CFM (316 CFM each) Supply airflow through floor tile = 515 CFM Supply air temperature = 53 F Raised floor plenum height = 16.5 inches Ceiling height (above the raised floor) = 9 ft Percent open specifications for perforated panels and leaky openings: Single floor tile: 25% Cable cutout in floor tile at rear of cabinet: 25% Front and rear cabinet doors: 63% Cabinet top panel: 25%

18 Case 1: Traditional Cabinet Design

19 Case 1: Traditional Cabinet Design

20 Case 1: Traditional Cabinet Design

21 Case 2: Cabinet with Air Dam Air Dams Introduced Air Dams Introduced Solid Top Panel Front and rear cabinet doors: 79% Perforation

22 Case 2: Cabinet with Air Dam

23 Internal Air Ducts Introduced Case 3: Air Dam & Internal Air Ducts te a ucts t oduced Solid Top Panel Front and rear cabinet doors: 79% Perforation

24 Cable Management Cable management no longer done for pride Increasing density & redundancy brings more data & power cable into cabinets Redundancy d also means more power strips Re-thinking cable management policies Overhead vs. Under floor Allows frequent access to cable Protects system static pressure

25 Importance of Cable Management Airflow from Server is blocked, cable support arms become heat sinks Temperature increases can have a significant impact on cabling systems The differences in the quality of the cable, for instance, between Category 6 and Category 6a cable can be significant Anixter LAB has done substantial testing ti on the impact of elevated temperature on copper cabling systems

26 Cable Cutouts must be sealed To ensure static pressure and maximize the efficiency of raised floor cooling, all holes in the floor must be sealed, including cable cutouts t

27 High Air-flow Dispensation Floor Tiles: Patented fit-all design and built in handles lbs. load rating 7 feet of dispersed air flow Removes Flat Bottom short cycles Cooling improvement 3-5 degrees bottom, 5-10 middle, degrees upper servers! 20-50% reduction in cooling costs through higher HVAC set points.

28 Perforated Floor Tiles Floor vents in a raised floor environment Average perforated floor tile delivers 300 to 500cfm Perforated tiles should only be located in cold aisles

29 Passive (Green) Thermal Management Solutions Filler Panels Air Dams Air Diverters Ducted Exhaust Solid Tops & Side Panels 65/35% Perforation Front & Back Doors Remove any Obstacles (i.e.. Cable Management) Well Sealed Floor Panels & Unwanted Openings High Flow Air Tiles

30 Data Center Layout Hot Aisle / Cold Aisle Close but Not Quite Right

31 Traditional Data Center Cabinet Arrangement Cabinets arranged front to back CRAC units positioned on perimeter of room Source: Optimizing data centers for high-density computing HP technology brief, 2 nd edition

32 Hot and Cold Aisles TIA 942 Even proper classic design may provide insufficient cooling for some high-density devices Source: TIA 942

33 Hot and Cold Aisle Placement Hot Aisle: Min 2 Cold Aisle: Min 3 Source: TIA 942

34 Cooling Concepts Standard Hot Aisle / Cold Aisle Front & Rear Vented Doors 63-68F in Cold Aisle 65-72F at server intake 90-95F at server exhaust Recirculation from exhaust back to the intake causes the CRAC units to be less efficient as they have to cool all of the white space first

35 Hot Aisle, Cold Aisle Airflow pattern for raised floor configuration with CRAC units at either end of hot aisles Source: Optimizing data centers for high-density computing HP technology brief, 2 nd edition

36 Thermal Management Common Mistakes Floor vents in a raised floor environment Proximity of floor vents to supply source Never closer than 8 As velocity decreases, static pressure increases Source: Optimizing data centers for high-density computing HP technology brief, 2 nd edition

37 Thermal Management Cooling system settings CRAC systems optimal when return air temp at maximum & humidity at lowest possible Disperse heat & power load when feasible

38 Thermal Management Alternate Solution Using drop ceiling as a return air plenum Reduce the distance hot air has to travel Source: Optimizing data centers for high-density computing HP technology brief, 2 nd edition

39 Progressive Layout Design Positioning of Air Delivery & Return Vents Supply airflow always in same direction as cable runs Locate CRAC units on either end of hot aisles

40 Inefficient Use of CRAC Unit Total Cooling = Latent Cooling + Sensible Cooling Latent Cooling Humidity decreases with no change in dry bulb air temperature Sensible Cooling Dry bulb air temperature decreases with no change in humidity

41 Temperature Variations Anixter Data Center

42 Airflow from Cabinets to CRAC s Anixter Data Center

43 Raised Floor Airflow Anixter Data Center

44 Isolated Return Air Path Hot air is segregated with return air ducts Rear door is sealed to prevent exhaust air from leaking into room Air Dams in front of cabinet prevent air recirculation inside cabinet Room A/C is easy to manage, with little regard to concentrated heat loads Cabinets can be placed and oriented any way desired Cold air delivery can be shared throughout room with fewer zone issues Total Heat Load Dissipated > 20 Kilowatts

45 Isolated Return Air Path I f ll d l d ith hi bi t th l th f th l In a room fully deployed with chimney cabinets, the only path for the supply air to return to the cooling unit is through a server

46 Passive Cooling Concepts Standard d Cold Aisle / Ducted Exhaust Front Vented Door / Solid Rear Door 63-68F in Cold Aisle 65-72F at server intake 90-95F at server exhaust The return air temp is increased which increases the CRAC unit efficiency The white space of the room does not get heated from the Hot aisle recirculation. The CRAC unit can run at a lower setting (cost savings) and still achieve the same Cold Aisle temps.

47 Passive Cooling Concepts Plenum Air Diverter / Ducted Exhaust Front Vented Door / Solid Rear 68-72F in white space 60-65F at server intake 90-95F at server exhaust Perforated tiles are required to cool the white space only The intake air is forced through an adjustable Air diverter directly from the CRAC. Having an adjustable opening allows the raised floor pressure to be maintained throughout the Data Center.

48 Passive Cooling Concepts Ducted Intake / Ducted Exhaust Solid Front Door / Solid Rear Door 68-72F in white space 60F at server intake 90-95F at server exhaust Perforated tiles are required to cool the white space only The intake air is completely contained and is able to be adjusted at the CRAC unit level. This concept can be implemented on slab floor as well. Less CapEX for building (cost of raised floor)

49 Passive Cooling Concepts - Cold Aisle Containment Eliminates mixing of air Addresses the air supply at the rack Cold air direct to server inlet, hot air dispersed into the room CRAC s installed outside the containment area Addresses the prevalence of existing Raised Floor environments Increased efficiencies at the CRAC s with increased intake temperatures

50 Passive Cooling Concepts - Aisle Containment Curtains Allows tuning of airflow CFM Supply to match CFM demand Promotes warmer return air temperatures to CRAC units Provides better supply temperature control Mid 70 s supply temperature Eliminates Hot Spots

51 Supplemental Cooling Units Close Coupled Cooling Close-coupled cooling aims to bring heat transfer closest to its source: the equipment rack Designed for high density environments >20kW per rack As compared to conventional CRAC/CRAHs, supplemental cooling units can reduce cooling costs by up to 30% Moving the air conditioner closer to the equipment rack ensures a more precise delivery of inlet air and a more immediate capture of exhaust air Use more efficient heat exchangers and delivers only sensible cooling, which is ideal for the dry heat generated by electronic equipment

52 High Density Cooling Options Precision Air Brings the air distribution and return much closer to the enclosures Units sit directly on or above the server enclosure Cold air delivery and hot air return much more precise Deployed overhead, the units do not occupy any floor space Eliminate hot-spots Flexible

53 High Density Cooling Options Door Heat Exchangers Replace the rear door of an existing rack Leverage the front to back air dissipation of most IT equipment Warm exhaust air passes through the heat exchanger coil and is returned to the room Return air similar to server inlet temperature Heat removal at source of heat Reduced real estate cost

54 High Density Cooling Options Hot Air Containment Uses In-Row, In-Line Air Conditioners Brings the functionality of the perimeter CRAC to a data center row Benefit is proximity: neither the cold air nor the hot exhaust air has far to travel Dimensions similar to the actual enclosures, modular Captures exhaust air at it s hottest temperature Most Efficient

55 Data Center Efficiency Metrics PUE Power Usage Effectiveness = Total Facility Power IT Equipment Power Total Facility Power delivered d to a site divided id d by the IT equipment power Total Facility Power is defined as the power measured at the utility meter The total power dedicated solely to the datacenter Difficult to identify in mixed-use buildings that house datacenters as one of a number of consumers of power PUE captures the efficiency of all components from input power, through UPS and to the RPP level A data center at 100 percent efficiency would have a PUE value of 1.0 DCiE Data Center Infrastructure Efficiency = IT Equipment Power x 100% Total Facility Power The inverse of PUE and another way to look at power and cooling efficiency of the IT equipment compared to the power coming in to the site Expressed as a percentage

56 Data Center Efficiency Metrics Reduce your operation costs by utilizing measurement, benchmarking, modeling, and analysis to improve your Data Center's energy efficiency. PUE DCiE Level of Efficiency i % Very Inefficient % Inefficient % Average % Efficient % Very Efficient Source: Green Grid

57 PUE /DCiE Most widely accepted, and adopted d benchmarks for efficiency i in data centers Both offer an uncomplicated metric that is easily to understand, measure, and discuss between IT, Facilities, and management Enables you enable you to compare how efficient your facility is compared with other data centers around the world Helps establish a benchmark you can track, report, and continually improve Keeping your data center energy efficient should be an ongoing process Implement power and cooling best practices to improve p p g p p efficiency and then monitor how those changes improved your PUE/DCIE

58 THANK YOU! MERCI! QUESTIONS?