3PAR InServ® E-Class/F-Class Storage Server Physical Planning Manual (320 - 200120 Rev F, September 2010)

4.17
3PAR InServ E-Class/F-Class Storage Server Physical Planning Manual
The air-conditioning units should have controls monitoring under the floor output that
respond to 2° F (1° C) and 5 percent relative humidity. Humidification is normally required to
replace moisture removed during the cooling process. The relative humidity for a subsystem
equipment room should be set at 40 percent. This level is sufficient to suppress
electromagnetic charge buildup, and low enough to avoid the risk of corrosion and
condensation. To avoid air contamination from the humidifier, water treatment may be
necessary in areas with high mineral content.
4.5.2 Air Supply and Flow
The air flow capacity of the facility where the InServ Storage Servers are installed needs to be
sufficient to remove the heat generated by the equipment. In addition, the air handlers must
provide the airflow volume required by the units being cooled. To ensure this airflow, the
facility must have a positive under the floor air pressure (if the facility has raised floors). When
conditions within the computer room are changed (new units are added, the computer system
is moved) airflow checks should be made.
The amount of outside (make-up) air should be kept to the minimum needed to create a slight
positive pressure within the room, and should not exceed industry recommendations of
0.3 cubic meter/minute (10 cubic feet/minute) per person stationed in the equipment room.
While recommendations for outside air in comfort air-conditioning are 10 to 15 percent of the
airflow, the computer room environment is cleaner and operates more efficiently if outside air
is kept below 1 percent of the airflow. Cooling/heating and humidification needs are reduced,
and a minimum of contaminated building air is introduced into the installation area.
4.5.3 Air Cleanliness
Air contaminants can cause equipment malfunction and can damage InServ Storage Servers. It
is essential that steps be taken to prevent air contaminants, such as metal particles, solvent
vapors, corrosive gases, soot, airborne fibers, or salt, from entering or being generated within
the server room environment.
A high-efficiency air filter should be employed on each air inlet for outside air to stop dust at
the point of entry to the installation site. Special additional filtering is necessary where the
environment is exposed to salt air, corrosive gases, or unusual dust/dirt conditions. Electronic
equipment is sensitive to air contaminants such as:
■ Excessive amounts of soot particles.
■ Condensate particulates such as carbonates.
■ Concrete particulates from unsealed concrete.