Environmental Specifications

This section provides the environmental, power dissipation, noise emission, and air flow specifications for the HP Integrity rx8620 Server.

Temperature and Humidity

The cabinet is actively cooled using forced convection in a Class C1-modified environment. The recommended humidity level for Class C1 is 40 to 55% relative humidity (RH).

Operating Environment

The system is designed to run continuously and meet reliability goals in an ambient temperature of
5° C-35° C at sea level. The maximum allowable temperature is derated 1° C per 1,000 feet of elevation above 5,000 feet above sea level up to 30° C at 10,000 feet. For optimum reliability and performance, the recommended operating range is 20° C to 25° C. This meets or exceeds the requirements for Class 2 in the corporate and ASHRAE standard. See Table C-4 on page 210.

Environmental Temperature Sensor

To ensure that the system is operating within the published limits, the ambient operating temperature is measured using a sensor placed on the server backplane. Data from the sensor is used to control the fan speed and also to initiate system overtemp shutdown.

Non-Operating Environment

The system is designed to withstand ambient temperatures between -40° C to 70° C under non-operating conditions.

Cooling

Internal Chassis Cooling

The cabinet incorporates front-to-back airflow across the system backplane. Nine 120-mm fans mounted externally on the front chassis wall behind the cosmetic front bezel push air into the unit. Twelve 120-mm fans housed in cosmetic plastic fan carriers and mounted externally to the rear chassis wall pull air through the unit.

Each fan is controlled by a smart fan control board embedded in the fan module plastic housing. The smart fan control board receives fan control input from the system fan controller on the system backplane and returns fan status information to the system fan controller. The smart fan control board also controls the power and the pulse width modulated control signal to the fan and monitors the speed indicator back from the fan. The fan status LED is driven by the smart fan control board.

Bulk Power Supply Cooling

Cooling for the bulk power supplies (BPS) is provided by two 60-mm fans contained within each BPS. Air flows into the front of the BPS and is exhausted out of the top of the power supply though upward facing vents near the rear of the supply. The air is then ducted out of the rear of the chassis.

PCI/Mass Storage Section Cooling

Six 92-mm fans located between the mass storage devices and the PCI card cage provide airflow through these devices. The PCI fans are powered off of housekeeping power and run at full speed at all times. The air is pulled through the mass storage devices and pushed through the PCI card cage. Separation is provided between the PCI bulkheads to allow adequate exhaust ventilation and to help reduce the localized airflow dead spots that typically occur at the faceplate tail of each PCI card.

Standby Cooling

Several components within the chassis consume significant amounts of power while the system is in standby mode. The system fans will run at a portion of full speed during standby to remove the resulting heat from the cabinet. The fans within the power supply will operate at full speed during standby.

Typical Power Dissipation and Cooling

provides calculations for configurations as described in the table.

Table B-5 Typical HP Integrity rx8620 Server Configurations

Cell Board	Memory per Cell Board	PCI Cards (assumes 10W each)	DVDs	Hard Disk Drives	Core I/O	Bulk Power Supplies	Typical Power	Typical Cooling
Qty	GBytes	Qty	Qty	Qty	Qty	Qty	Watts	BTU/hour
4	16	16	2	4	2	6	3800	12973
4	8	16	2	4	2	6	3395	11591
4	4	8	0	2	2	6	3177	10846
2	16	16	2	4	2	4	2241	7651
2	8	8	0	2	2	4	1936	6610
2	4	8	0	2	2	4	1880	6418
1	4	8	0	1	1	3	1228	4192

The air-conditioning data in Table B-5 “Typical HP Integrity rx8620 Server Configurations” is derived using the following equations.

Watts x (0.860) = kcal/hour
Watts x (3.414) = Btu/hour
BTU/hour divided by 12,000 = tons of refrigeration required




	NOTE: When determining power requirements, you must consider any peripheral equipment that will be installed during initial installation or as a later update. Refer to the applicable documentation for such devices to determine the power and air-conditioning that is required to support these devices.

Acoustic Noise Specification

The acoustic noise specification for the HP Integrity rx8620 Server is 55.6 db (sound pressure level at bystander position). It is appropriate for dedicated computer room environments, not office environments. The LwA is 7.4 Bels. Care should be taken to understand the acoustic noise specifications relative to operator positions within the computer room or when adding servers to computer rooms with existing noise sources.

Air Flow

The recommended HP Integrity rx8620 Server cabinet air intake temperature is between 68° F and 77° F (20° C and 25° C) at 960 CFM.

Figure B-1 “Airflow Diagram ” illustrates the location of the inlet and outlet airducts on a single cabinet. Air is drawn into the front of the HP Integrity rx8620 Server and forced out the rear.

Figure B-1 Airflow Diagram