Technical Specifications

Starting a New Equipment Cooling Project
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2.0 STARTING A NEW EQUIPMENT COOLING PROJECT
2.1 Determining Cooling Equipment Needs
2.2 Implementing a Hot-Aisle/Cold Aisle Design
A best practice is to place equipment racks in alternating rows of cold aisles and hot aisles. This is
best accomplished when the layout of the file-server farm area is being planned. It is more difficult to
accomplish when the computer room is already populated with operating hardware.
In the cold aisle, the equipment racks are arranged face-to-face so the cooling air from the computer
room cooling unit discharged up through the perforated floor tiles is drawn into the face of the
computer hardware and exhausted out the back of the equipment rack into the adjacent hot aisles.
Hot aisles are literally hot because the objective of the alternating cold and hot aisle design is to
separate the source of cooling air from hot air discharge, which returns to the computer-room cooling
unit. Therefore, no perforated tiles should be placed in the hot aisles. This would mix hot and cold air,
lowering the temperature of the air returning to the cooling units, reducing their usable capacity.
1. Is adequate space available for a Liebert XD installation?
2. Is the hot aisle/cold aisle approach being utilized for this room design or can it
be utilized in this room design?
3. Is redundant cooling equipment required?
4. Are there access considerations for all components (possible rigging problems)
5. What heat load growth is anticipated over the next few years?
6. How are the cabinets going to be populated (density of heat generation)?
7. What monitoring requirements are desired or needed?
8. Who will be involved in this project (stakeholders)?
9. Is there existing computer room environmental cooling systems for humidity
control and filtration?
10. Is the vapor barrier sufficient?
11. Is a chilled water system available?
a. What is the system’s capacity?
b. What is the system’s chilled water supply temperature?
c. Does the chilled water supply temperature vary during the year or is the
temperature constant?
12. How much power is available for cooling equipment?
13. What is the maximum distance between the Liebert XDP/Liebert XDC unit
and the farthest Liebert XD cooling module in the proposed layout?
14. If an air-cooled Liebert XDC is used—is an area available for the remote
condenser?
15. Does the Liebert XD system refrigerant volume exceed 13 lb/1000ft
3
? If so, a
refrigerant detection and removal equipment may be required. Refer to 3.22 -
Liebert XD Refrigerant.