Emerson Xtreme Density Liebert XDO Placement, Determining Spacing of Liebert XDOs in an Aisle

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Designing a Liebert XD Solution

3.6Liebert XDO Placement

3.6.1Determining Spacing of Liebert XDOs in an Aisle

Liebert XDO units should be placed in rows directly above the cold aisles of a room for optimum cool- ing. Each Liebert XDO serves an area equal in width to the cold aisle spacing, typically 12 to 16 feet (3.7 to 4.9m). The length of the area served includes any space between Liebert XDO modules in a row. Depending on the cooling capacity to be achieved, spacing between Liebert XDO modules in a row may vary from zero to as much as 6 feet (1.8m). When the spacing increases to more than 6 feet (1.8m), overall performance of the system may be negatively affected and gaps in cooling may occur.

Emerson recommends installing one Liebert XDO at the end of each aisle being cooled and to space the remainder between these end units in pairs as shown in Figure 15. This layout will block the incursion of hot air around the side of the end cabinets.

Figure 14 Liebert XDO placement over cold aisle

XDO

Hot air is

XDO

drawn into

 

the XDO for

 

 

cooling

 

Critical

Equipment

Critical

Equipment

Cooled air enters the

rack...

Hot air goes into the hot aisle

COLD AISLE

Critical

Critical

Equipment

Equipment

Cooled air

 

enters the

 

rack...

 

Hot air goes

 

into the hot

 

aisle

 

HOT AISLE

COLD AISLE

Cold Aisle Spacing

Table 3 can be used to determine the correct number and spacing of Liebert XDOs.

Table 3 Calculating quantity and spacing of Liebert XDO modules (example below is Liebert XDO20)

Input Information

Step

Result

Total heat load in the room, kW

A

 

Reserve capacity needed

B

 

(10% to 25% of A is recommended)

 

 

 

 

C

Required cooling capacity, kW = A + B

Existing/planned Liebert Deluxe/DS unit

D

 

sensible capacity, kW

 

 

 

 

E

Required Liebert XD system cooling capacity, kW = C – D

 

F

Number of Liebert XDO20s required = E ÷ 20, rounded up (60Hz)

 

= E ÷ 16, rounded up (50Hz)

 

 

 

G

Number of Liebert XDP/Liebert XDC modules required = F ÷ 8,

 

rounded up (60Hz and 50Hz)

 

 

Room area, square feet

H

 

 

I

Area served by each Liebert XDO20 = H ÷ F

Spacing of cold aisles, center-to-center,

J

 

typically 12-16 ft (3.7 to 4.9m)

 

 

 

 

K

Spacing between each Liebert XDO = (I ÷ J) - 2

 

 

Required Liebert XD system cooling density = E x 1000 ÷ H

 

L

OK if under 640; otherwise, additional cooling is required from

 

 

Liebert Deluxe or Liebert DS units.

15

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Contents Liebert Xtreme Density Page Table of Contents XDH and Liebert Xdcf SpecificationsIii Tables Liquid Liquid/Vapor Mix CoolFrame, XDH European Union Fluorinated Greenhouse Gas Requirements Direct and Indirect System ConfigurationsLiebert Heat Rejection Air Cooled or Water/Glycol Cooled Pumped RefrigerantLiebert XDO-Overhead Cooling Module Liebert XDV-Vertical, Above-Cabinet Cooling Module Liebert XDH-Horizontal Cooling Module Liebert Xdcf units on BladeFrame EX cabinets Liebert XdcfLiebert XDA-Air Flow Enhancer Liebert XDP Minimum Load Liebert XDP-Pumping UnitLiebert XDC Minimum Load Liebert XDC-Refrigerant ChillerLiebert XD Piping Liebert XD field-installed port kits header connection sizeLiebert XD Field Piping Flexible Piping Kit Prefabricated HeadersDetermining Cooling Equipment Needs Hot aisle-cold aisle arrangement with under-floor source Implementing a Hot-Aisle/Cold Aisle DesignCalculate the Heat Load to be Handled by Liebert XD System Determine Cooling Requirements and Select Liebert XD SystemConfiguring a Liebert XD System Airflow Requirements for Liebert XD SolutionsSelecting Liebert XD Cooling Modules Number of Modules Supported by a Liebert XDP or Liebert XDCDetermining Spacing of Liebert XDOs in an Aisle Liebert XDO PlacementLiebert XDO spacing-horizontal and vertical Liebert XDV Unit Placement Liebert XDV is suspended From ceiling structureInput Information Step Results Liebert Xdcf unit mounting locations Liebert Xdcf PlacementLiebert XDP/Liebert XDC Placement Liebert XDH PlacementFor enhanced protection Interlaced piping arrangementInterlaced piping arrangement for enhanced protection For enhancedProtection Liebert XD Piping System Design Liebert XD RefrigerantKey to Piping Pipe Function Size / Equivalent Pipe Length Supply, return pipe sizes for refrigerant loopBypass Flow Controllers Liebert XD Piping SlopeRefrigerant Pumped XD CoolFrame, XDH, XDO or XDVLiebert XDP Liebert XDC Determining Refrigerant Volume Liebert XDP/Liebert XDC Pumped R-134a Circuit VolumeSystem refrigerant charge for the supply and return mains Return Line Diameter Return Line Diameter 5/8Calculating Refrigerant Charge-Example Liebert XDC DX R-407c Circuit Volume-Air Cooled UnitsCalculating refrigerant charge-example Worksheet to calculate refrigerant chargeElectrical Chilled Water PipingOutdoor condenser charge-R-407c Indoor water/glycol cooled module R-407c refrigerant chargeOptional Features Liebert XDO Liebert XDO Standard FeaturesLeft Side XDO 24-1/8 Rear of XDO Liebert XDO internal mounting location Liebert XDO top and front electrical access points Liebert XDV Standard FeaturesLiebert XDV dimensions Optional Features-Liebert XDVDetail Area a Detail a Power Source Liebert XDV electrical connections for CSA-approved units Suspending single Liebert XDV from Unistruts Page Liebert Xdcf Standard Features Liebert XDPXD CoolFrame, XDH, XDO or XDV Liebert Xdcf Mechanical Considerations Liebert TMReturn Pipe Liebert Xdcf Installation Considerations Liebert Xdcf Piping Connection Methods and PointsEgenera BladeFrame Liebert XDH Standard Features Optional Features-Liebert XDHHeader System Supply and return piping connections Liebert XDH dimensionsRear XD Cooling Module Either 5/8 or 7/8 Or 2-5/8 O.DRecommended Arc Refer to for detailsLiebert XD Flex Pipe assemblies, supply and return Liebert XD Flex Pipe KitLiebert XD Liebert XDV CoolFrame Liebert XDHLiebert XD Piping Dimensions and Features Piping Installation Method prefabricated headersTwo-port prefabricated piping legend Branch Piping Standard Run Long Run Four Port 186551G21 Four-port prefabricated piping legendBranch Piping Standard Run Long Run Five Port Five-port prefabricated piping legendBranch Piping Standard Run Long Run Ten Port 186650G51 Ten-port prefabricated piping legend33-1/8 990 1067 XDP160 Liebert XDP Standard FeaturesModel Pipe Connection Point 50/60 HZ Unit piping outlet connection sizes, inches, OD CuEnclosure Cover Customer Power Liebert XDC Optional Features Liebert XDC Standard FeaturesLiebert XD Chiller piping connection sizes Liebert XDC piping locationsLiebert XDC Water/Glycol Piping Connection Sizes Piping locations-floor stand and valve assembly Front view of Liebert XDC and electrical enclosures Switch Transformer Electrical handy box, factory-installed with cover Liebert XDC Extra Low Voltage field connections points Liebert XDC160 specifications Heat Rejection Equipment Performance DataPiping Connections Performance Data204 Liebert XDP160 specifications Liebert XDO16 specifications Liebert XDO20 specifications Pipe Connections without flex pipeSides, Front and Rear Liebert XDO20 dimensions-domestic and export Liebert XDV8 specifications Liebert XDV10 specifications Liebert XDV8 dimensions-domestic and export Liebert XDV10 dimensions-domestic and exportLiebert Xdcf specifications Liebert XDH specifications Specifications Specifications Page Iti Ne tTi n That