HP Performance-Optimized Datacenter, 12 m (40 ft) User Guide

Cooling system 19
Cooling system
HP POD cooling system
CAUTION: Contaminated supply water might cause decreased cooling capacity or disruption
in service. The supply water must meet the guidelines states in the HP Performance-Optimized
Datacenter Site Requirements Information document. Damage caused by contaminated supply
water is not covered by the warranty.
The HP POD has 12 heat exchangers that maintain temperature and cool the equipment installed in the
HP POD. The HP POD receives chilled water from your facility, cycles the water through the heat
exchangers to cool the air, and then the fans circulate the cool air throughout the HP POD.
To control the fan speed, you must set a cold aisle temperature through the ECS. A predetermined
differential pressure setpoint between the hot aisle temperature and cold aisle temperature is factory set,
and cannot be altered. The fan units regulate speeds to maintain the cold aisle temperature and
differential pressure between the hot and cold aisle. For more information, see Controlling the fan speed
(on page 19).
Water supply temperature
The temperature of the water supplied to the HP POD must be 13°C to 24°C (55°F to 75°F). Freezing
water might cause a blockage and damage to the unit.
The minimum server inlet temperature is 10°C (50°F).
Controlling the fan speed
The HP POD fans operate at variable speeds to maintain two setpoints, programmed into the ECS:
• Hot aisle temperature setpoint
• Differential pressure setpoint between the hot and cold aisles
The fan speed adjusts to maintain both setpoints. You cannot manually adjust the fan speed.
Depending on the IT equipment you have installed in your HP POD, you can change both of these factory
set parameters to improve the overall efficiency of your system. For more information, contact HP ("HP
contact information" on page 50).
To access the fan units:
1. Unlock the latch for that fan overhead.