1) Monitor and manage the critical parameters associated with equipment installation, by area of the computer room (no more than two building bays):
Space: number of cabinets and rack unit space available vs. utilized
Power: PDU output available vs. utilized
Breaker positions: available vs. utilized
Sensible/redundant cooling capacity available vs. utilized
Floor loading: acceptable weight vs. installed cabinet and equipment weight plus dead load of floor and cables, plus live load of people working in area. Compare the actual floor load with the subfloor structural strength.
Raised floor and overhead space
2) Create a raised floor master plan
3) Establish minimum raised-floor height
24″ if the cabling is overhead, with no chilled water or condenser water pipes under the floor blocking the airflow
Recommend 30-36″ if there are airflow blockages
4) Establish a minimum clearance of 3′ from the top of the cabinets to the ceiling
5) Seal all penetrations in the subfloor and perimeter walls under the raised floor and above the dropped ceiling
Hot/cold aisle
6) Install computer and infrastructure equipment cabinets in the cold aisle/hot aisle arrangement
14′ cold aisle to cold aisle separation with cabinets 42″ deep or less
16′ cold aisle to cold aisle separation with cabinets > 42″ to 48″ deep
7) Utilize proper spacing of the cold aisle
48″ wide with two full rows of tiles which can be removed
All perforated tiles are only located in the cold aisle
8 ) Utilize proper spacing of the hot aisles
Minimum 36″ with at least one row of tiles able to be removed
Do not place perforated tiles on the hot aisles
9) Ensure cabinets are installed with the front face of the frame set on a tile seam in the cold aisle
10) Require cabinet door faces to have a minimum of 50% open perforation – 65% is better
11) Prevent internal hot air recirculation by sealing the front of cabinets with blanking plates, including empty areas in the equipment-mounting surface, between the mounting rails, and the edges of the cabinets (if necessary)
Power and cooling equipment
12) Put PDUs and remote power panels in line with computer equipment cabinet rows occupying cabinet positions
13) Place cooling units at the end of the equipment rows, aligned with hot aisles where possible
14) Face cooling units in the same direction — no “circle the wagons” aka, uniformly distributed cooling
15) Limit maximum cooling unit throw distance to 50′
16) Create appropriate cooling capacity, with redundancy, in each zone of the room (zone maximum is one to two building bays)
Install minimum of two cooling units even if only one is needed
Install one-in-six to one-in-eight redundant cooling units in larger areas
17) Use only sensible cooling at 72F/45%rh when calculating the capacity of cooling units
18) Place chilled or condenser water pipes in suppressed utility trenches if the computer room is built on grade
19) Ensure all cooling units are functioning properly
Set points and sensitivities are consistent
Return air sensors are in calibration – calibrate the calibrator
Airflow volume is at a specific level
Unit is functioning properly at return air conditions
Unit produces at least 15 degree delta T at 100% capacity
20) Be sure the cooling unit’s blower motor is turned off if the throttling valve sticks (chilled water type units) or if a compressor fails (air conditioning type unit)
21) Adjust chilled water temperature to eliminate latent cooling
Perforated tiles
22) The maximum number of perforated tiles is the total cooling unit airflow divided by 750cfm = maximum number of perforated tiles to be installed
Install only the number of perforated tiles necessary to cool the load being dissipated in the cabinet/rack in the area immediately adjacent to the perf tile
Turn off cooling units that are not required by the heat load (except for redundant units)
23) Do not use perforated tile air flow dampers and remove all existing dampers from the bottom of perforated tiles (reduces maximum air flow by 1/3, the often close unexplainably and they potentially can produce zinc whiskers)
Cabling
24) Seal all cable cutouts and other openings in the raised floor with closures
25) Spread power cables out on the subfloor, preferably under the cold aisle to minimize airflow restrictions
26) If overhead cable racks are used, the racks should run parallel to the rows of racks. Crossover points between rows of racks should be located as far from the cooling units serving the area as practical
27) Place data cables in trays at the stringer level in the hot aisle