Airflow Management in Data Rooms Data Room Cooling

Airflow Management in Data Rooms

Data Room Cooling Load Density Smaller, Sq. Cheaper, Faster Ft. / Ton dropping Indoor Air Temperatures are Rising Density and down time 99. 999% Reliability -5. 26 minutes/year CRAC restart time

Redundancy Requirements IT equipment and heat Thermal shut off Shortened life > 80. 6°F Need for redundant equipment Average $9, 000/minute of downtime What is N + 1 in the real world Air-cooled Chilled water? Dual Cooling

30 Ton Unit at Different E. A. T. 72/60/52. 2 80/63. 6/52. 2 85/67. 5/52. 2 (DB/WB/DP) Total Capacity MBH 371. 9 393. 5 405. 5 Sensible Capacity MBH 318. 9 393. 5 405. 5 CFM/Ton 452 423 396 Leaving Air Temperature 50. 9/50. 3 54. 1/53. 1 58. 2/54. 9 14, 000 CFM Source: Data Aire Product Selector Guide

5 Steps to Improved Air Flow Separate the hot air from the cold air Capture the hottest air possible Locate air returns high and air supplies low Use remote mount sensors Use direct drive plenum fans

Airflow Management Hot Aisle – Cold Aisle

Better 30 Ton DX Best 30 Ton DX Cold Aisle Server Racks Hot Aisle 30 Ton DX Server Racks Cold Aisle Server Racks Hot Aisle Server Racks Cold Aisle Equipment Layout – Down Flow 30 Ton DX

Equipment Layout 30 Ton DX (down flow) 30 Ton DX Cold Hot Cold Hot 30 Ton DX Worse 30 Ton DX Worst

Ceiling return air plenum Return Air Plenum Data Room Cold Aisle T H Server Racks Under floor supply air plenum Server Racks

Bypass Within Racks Empty Space Between Servers 12

Control Bypass Air Racks Size “U” dimension Blank Off Panels

Airflow Management Standard Tile @ 0. 10” SP 550 CFM w/ Damper 750 CFM w/o Damper Rule of Thumb 1. 0 - 1. 5 ton cooling/tile 5. 0 KW cooling/tile

Airflow Management High Capacity Tile @ 0. 10” SP 1583 CFM w/ Damper 2837 CFM w/o Damper Rule of Thumb 4 to 6 tons/tile 15 KW cooling/tile

Airflow Management With Forward Curved Fans ● Fans sensitive to raised floor height Cannot place racks close to CRAC unit ● Raised floor area is not a plenum ● Minimum 24” to 36” raised floor

Airflow Management With Direct Drive Plenum Fans ● Raised floor is a plenum 12” raised floor height OK Place racks as close to CRAC units as desired ● Lower energy cost ● Quick Changeouts

Plug Fans

Typical layouts without a raised floor

Single Row of Racks Return Air Through Room T H Cold Aisle Server Racks CRAC Unit Hot Aisle PLAN VIEW

Free Blow Plenum Supply Front Return CRAC Redundancy is possibly an issue Hot Cold CRAC PLAN VIEW Hot

Free Blow Plenum Supply Front Return Supply Air Opening Server Rack Server Rack ELEVATION Return Air Openings CRAC Unit

Free Blow Through Floor Stand Supply Plenum Return Air Openings CRAC Unit Server Rack Server Rack Supply Air Opening SIDE ELEVATION

Free Blow Through Floor Stand Supply Plenum Ceiling Supply Plenum Supply Grilles as required sized to blow to end of cold aisle FRONT ELEVATION

Ducted Supply Applications With Multiple Fan Units SMACNA Recommended Diverging Angle <= 7° Fan 1 Fan 2 CRAC Unit Front View Fan 3

Plenum CRAC Unit Side View Front View Only Use Ducted Plenum With Plug Fans!

Standby Unit Ducting Discharge Plenum Cold Hot PLAN VIEW CRAC T H Hot CRAC Duct Run Out

Supply Duct CRAC-1 Compressor Section Supply Duct Return Duct Supply Duct CRAC-1 Fan Section Decorative Return Air Plenum CRAC-2 Fan Section CRAC-2 Compressor Section RA into sides Of CRACs Minimum 12” clearance between bottom of trunk duct and RA inlet

Ducted Supply Return Air Through Room Server Rack Server Rack ELEVATION Return Air Openings CRAC Unit

Plenum Built Around CRAC Unit (High Wall Return) Server Rack Cold Aisle Server Rack Hot Aisle Server Rack Cold Aisle Server Rack ELEVATION CRAC Unit

Wrap Up Perform a Reality Check Separate the Hot Air From the Cold Air Capture the Hottest Air Possible Locate Air Returns High Locate Air Supplies Low Use Remote Mount Sensors Always Use Plenum Fans

Questions?