The AOC machine room

• 2100 square feet, raised floor environment
• Two water-cooled Computer Room Air Handlers (CRAH)
• Cold air supply under floor (plenum)
• Flooded hot air return

Observations

• ALMA racks can cause air recirculation. Should be rotated.
• Mark5s blow hot air into room and into SWC.
• Our racks would be better if rotated 180
  • The cold air is pulled by the CRAH
  • The hot air can be pulled into the cold aisle
• The VLBA correlator is a good design

Conclusions

• prevent mixing of hot and cold air
  • remove wasted space in racks (blanking panels, pancake)
  • face racks appropriately (perferated tiles, hot air exhaust)
  • under-rack brushes for wire openings
• prevent wasting air pressure
  • under-rack brushes for wire openings
  • use perforated tiles only where necessary
  • move network cables from under floor to overhead

References

• APC White Paper #44
• Alternating Cold and Hot Aisles - Sullivan