HP 9000 rp4410-4 Site Preparation Guide, Third Edition - HP 9000 rp4410/rp4440 - Page 19

System Specifications Environmental Specifications Environmental Specifications This section provides the temperature and humidity requirements, noise emission, and air flow specifications for the HP server. Temperature and Humidity The recommended operating range is 20°C to 25°C and 40% - 55% relative humidity. Ambient intake air temperature is often different from ambient room temperature; you should measure the operating temperature and humidity directly in front of the cabinet cooling air intakes rather than just checking ambient room conditions. Operating Environment The system is designed to run continuously and meet reliability goals in an ambient temperature of 5°C to 35°C (+40°F to +95°F) at sea level. The maximum allowable temperature is de-rated 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 and 40% - 55% relative humidity. Environmental Temperature Sensor The server includes internal sensors that monitor input air temperature and server operating temperatures. The ambient air temperature is measured using a sensor placed on the system I/O board. Data from the sensor is used to control the fan speed and also to initiate system overtemp shutdown. Nonoperating Environment The system is designed to withstand ambient temperatures between -40°C to 70°C under non-operating conditions. Cooling CPU/Memory Cooling The server incorporates front to back airflow across the processor and memory extender boards and through the HDD backplane. Two 127 mm dual fan assemblies, mounted vertically in the center of the chassis, pull air through the processor and memory section, and push air through the PCI section. Each processor/memory dedicated dual fan assembly is controlled by smart fan control circuits that are embedded in the system I/O board. The smart fan control circuit receives fan control input from the system fan controller in the I/O board, and returns fan status information to the system fan controller. The smart fan circuit controls the power and the pulse-width-modulated control signal to the fan and monitors the speed indicator back from each of the fans. The fan status LED is driven by the smart fan circuit. The location of the fan status LED is on the diagnostic board inside the system. Bulk Power Supply Cooling Cooling for the bulk power supplies is provided by the one 120 mm dual fan assembly and one externally mounted 60 mm power supply fan. Air is pushed into both power supply bays by the 120 mm fan assembly and exhausted out the rear by a 60 mm fan (one fan per PSU). Chapter 1 19