Free Cooling in Data Centers. John Speck, RCDD, DCDC JFC Solutions

Transcription

1 Free Cooling in Data Centers John Speck, RCDD, DCDC JFC Solutions

2 Why this topic Many data center projects or retrofits do not have a comprehensive analyses of systems power consumption completed in the design phase Many cooling systems do not take advantage of lower ambient temperatures when available. As system designers and influencers we should try to help customers make smart and efficient data center decisions

3 Data Center Power Use Data Centers can use 100 times more energy than a standard office cebuilding. Often, less than 15% of original source energy is used for the information technology equipment within a data center Source:

4 Introduction to PUE PUE is a measure of how effectively energy is used to support the facilities computer load. PUE is calculated by: Complete facility power IT Equipment Energy 500kW facility with a 250kW computer load = PUE of 2.0

5 PUE as Reported by Google Comprehensive PUE Source:

6 PUE as Reported by Google

7 That s great What about the rest of us! According to results from a recent Digital Realty Trust survey of selected large companies (greater than $1 billion in annual revenue or more than 5,000 employees) in North America, the average power usage effectiveness (PUE) is 2.9 The survey found that only 20% of participants reported a PUE below 2.0 Ouch!!!

8 How do they do it! What do large mega data centers have that small and mid size data centers do not! A = Free cooling (Economizers) C = Efficient cooling infrastructure B = Efficient power infrastructure

9 Data Center Power Use 500 PUE 2.4 Servers 42% CRAC 41% Cooling Lighting 1% UPS 2% Transformers 6% Condenser 8% Cooling

10 Data Center Power Use PUE 2.0 Computer Load 50% AHU 15% Cooling Chiller 23% Cooling Lighting 1% 0% UPS 2% Pumps 3% [CATEGORY NAME] [PERCENTAGE] Cooling

11 Data Center Power Use 500 PUE 1.6 Computer Load 63% AHU1 15% Chiller 11% Cooling Cooling Pumps 2% 0% Lighting 1% Transformers 6% UPS 2%

12 Data Center Power Use - PUE 1.2 Cooling Economizer 12% UPS 1% Transformers 4% Lighting 1% Computer Load 82%

13 PUE Data center power use is closely tied to cooling efficiency PUE is a snapshot of one moment in time A properly designed cooling system should be much more efficient when the ambient temperature is low. PUE should be averaged over an entire year to truly show a sites power consumption during all 4 seasons. PUE varies considerably in a 24 hour period (Or it should).

14 DC Cooling with Glycol Economizer DC Kw/H CRAC 1 kwh CRAC2 kwh CRAC3 kwh CRAC4 kwh Fluid Cooler Total PUMP L23 P-15 Pumps Lighting PUE Total Cooling Night Time Mid day Afternoon

15 April 12, :00:00 0 1:00:00 0 2:00:00 0 3:00:00 0 4:00:00 0 5:00:00 0 6:00:00 0 7:00:00 0 8:00:00 0 9:00: :00: :00: :00: :00: :00: :00: :00: :00: :00: :00: :00: :00: :00: :00:00 0 Supply to Fluid Coolers Return from Fluid Coolers OAT Total Cooling Supply to Fluid Return from Date Time Power Use IT Load Coolers Fluid Coolers OAT PUEc 4/12/2013 0:00: /12/2013 1:00: /12/2013 2:00: /12/2013 3:00: /12/2013 4:00: /12/2013 5:00: /12/2013 6:00: /12/2013 7:00: /12/2013 8:00: /12/2013 9:00: /12/ :00: /12/ :00: /12/ :00: /12/ :00: /12/ :00: /12/ :00: /12/ :00: /12/ :00: /12/ :00: /12/ :00: /12/ :00: /12/ :00: /12/ :00: /12/ :00:

16 Types of Economizers Airside Waterside

17 Direct Airside Economization - Winter Exhaust Air Mixing Outdoor Air CRAC Rack Rack

18 Airside Economizer - Summer Exhaust Air Outdoor Air CRAC Compre Rack Rack Outdoor Unit = ssor

19 Glycol Economizer - Winter Outside Air FAN Outdoor unit Water/Glycol Pump CRAC = No Compr ressor Rack Rack

20 Glycol Economizer - Summer Outside Air FAN Outdoor Unit Water/Glycol Pump CRAC = Compres ssor Rack Rack

21 Chilled Water System Outside Air FAN Chiller = Compressor Water/Glycol Pump No Compr ressor CRAH = C FAN Coil + Rack Rack

22 Chilled Water System with Economizer Outside Air FAN Chiller = Compressor FAN Economizer Water/Glycol Pump No Compr ressor CRAH = C FAN Coil + Rack Rack

23 Chilled Water System - Rear Door with Economizer Outside Air FAN Chiller = Compressor FAN Economizer Heat excha anger Rack Rack Heat excha anger Pump Water/Glycol

24 Chilled Water System with Inrow Cooling Outside Air FAN FAN Chiller = Compressor Economizer Rack Rack Pump Water/Glycol

25 Inrow Cooling

26 Inrow Cooling with Containment

27 Indirect Air-side Economizer Rack Rack Outdoor Air Indoor Air

28 Evaporative Cooling Evaporative cooling enhances the effectiveness of Airside AND Waterside economization by cooling close to the ambient wet bulb temperature.

29 Wet Bulb Cooling Effectiveness - BC

30 Free Cooling Analyses - Canada Analyses of cooling effectiveness in various Canadian cities Supply temperature to server = 24 Celsius Efficiency of the various types of free cooling systems varies by design, heat load, and location and is not the focus of this presentation

31 Vancouver, British Columbia Mechanical Cooling + Evaporation Free Cooling - Evaporation Free Cooling - Dry

32 Toronto, Ontario Mechanical Cooling + Evaporation Free Cooling - Evaporation Free Cooling - Dry

33 Montreal, Quebec Mechanical Cooling + Evaporation Free Cooling - Evaporation Free Cooling - Dry

34 Calgary, Alberta Free Cooling - Evaporation Free Cooling - Dry

35 Considerations for Selecting a Type of Economizer Location Server supply temperature Chilled water supply temperature Location of data center / computer room in building Budget Cost of power

36 Common Objections to Free Cooling It s great idea, but it is very expensive - Efficient cooling systems are cost effective when you consider the facility cost per kw, cost of power use etc. It does not work well in this climate There is usually a good option for economization when you consider all of the design options that are available It is too cold for free cooling to work here properly - This can be a concern for chilled water systems, but alternatives are available

37 Retrofit Projects -

38 Improving Heat Rejection Performance In retrofit projects, there is sometimes no payback for replacing an existing cooling system. Note the following improvements as listed in the BICSI DCDC Data Center Design and Implementation best practices

39 Targets for Retrofit Improvement - DCDC % of improvement possible Area for attention 10-40% hot-aisle or cold-aisle containment 10-40% cabinets with isolated air supply or isolated air return 1 6% Optimized quantity and location of floor vents only in the cold aisles, assisted by computational fluid dynamics (CFD)

40 Targets for Retrofit Improvement - DCDC % of improvement possible Area for attention 1 5% or more use of blanking panels in equipment racks to prevent mixing of cold inlet air and hot exhaust air. 1 5% or more blocking access floor cable cut-outs and sealing floor tile openings to prevent escape of cold air where it is not needed

41 Targets for Retrofit Improvement - DCDC 10-40% hot-aisle or cold-aisle containment 10-40% cabinets with isolated air supply or isolated air return This is the same result, from different methods

42 Cooling Utilization - It is all about Delta T Delta T = 2C Total Cooling 3.5 kw/h

43 Delta T = 8C Total Cooling 11 kw/h

44 Airflow Requirements of Servers CFM = 1.78 equipment power (W) temperature difference ( C) 1.78 x 300 Watts = 574/8 (Delta T) = 66 CFM With 10 servers noted above installed in a cabinet the cool air requirement would be estimated at 660 CFM at a 8 Celsius temperature rise If a cooling unit produces 4000 CFM of airflow. How much of it makes it to the server inlet? How much is bypassed?

45 Adding Containment has a Large Impact

46

47 Airflow Analyses Data Center Row Air recirculation Air recirculation

48 Data Center Row Without Containment Air recirculation

49 Data Center Row Without Containment Air recirculation Air recirculation

50 Airflow Analyses Data Center Row Air recirculation Air recirculation

51 Inlet Temperature Analyses Server Row Rack inlet supply TEMP to high Air recirculation i

52 Side View With Containment No recirculation

53 Top View With Containment Only cool air is delivered to load

54 Containment Result With VFD at 70% No hot spots VFD at 70%

55 Containment Result With VFD at 70% No hot spots

56 Key Point: Fan Power Versus Fan Speed

57 Turn it up! Sun Microsystems Data center managers can save 4 percent in energy costs for every degree of upward change in the set point... Lawrence Berkeley Labs found that raising the chilled water temperature from 42F (5.5C) degrees to 55F degrees (13C) could improve chiller efficiency by 15 to 25 percent!

58 ASHRAE Typically, the equipment selected for data centers is designed to meet either Class 1 or 2 requirements. Class 3 is for applications such as personal computers and Class 4 is for applications such as point of sale IT equipment used indoors or outdoors.

59 Where to Measure Supply Temperature

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61 ASHRAE Locations for Temperature Sensors T T T T

62 Customer Metering Examples

63 Room Cooling

64 Data Center Temperature Networking gear is exhausting into the Cold Aisle Rack Supply TEMP is extremely low Space is over cooled. Hot Aisle is not that warm

65 Pressure PA

66 Cooling Unit TEMP and Delta T Target Delta T for the cooling units is not being reached. Units are supplying to low a temperature. CRAC return temperatures are lower than most Data Centers rack supply temperature

67 Rack Cooling Supply and Return Racks highlighted in yellow are being supplied air that is below the ASHRAE recommended minimum temperature

68 Business Case for PUE Consider our PUE examples presented earlier PUE CPU Load Total power Annual kwh kwh$ Yearly $ 5 Year $ 10 year $ ,512, $840,960 $4,204,800 $8,409, ,760, $700,800 $3,504,000 $7,008, ,008, $560,640 $2,803,200 $5,606, ,256, $420,480 $2,102,400 $4,204,800

69 A Closer Look at the Numbers PUE Yearly $ 5Year$ 10 year $ 2.4 $840,960 $4,204,800 $8,409,600 2 $700,800 $3,504,000 $7,008, $560,640 $2,803,200 $5,606, $420,480 $2,102,400 $4,204,800 Electrical l Savings of $4,204K Over 10 years

70 A Closer Look at the Numbers PUE Yearly $ 5Year$ 10 year $ 2.4 $840,960 $4,204,800 $8,409,600 Total Facility Power 1200 KW 2 $700,800 $3,504,000 $7,008, $560,640 $2,803,200 $5,606, $420,480 $2,102,400 $4,204,800 Total Facility Power 600 KW

71 Business Case Detailed Analyses What is the cost to build out the extra 600 kw electrical infrastructure to support an inefficient data center Generator Switchgear Electrical distribution

72 Closing Comments Economization and data center optimization are practical ways to improve your data centers planned or current power use. Airside containment strategies and metering temperature and pressure at the racks is the correct method for assuring proper heat rejection performance

73 Thank You John Speck, RCDD, DCDC JFC Solutions Telephone: