Particulate Contamination
94
G8264 Installation Guide
Attention: Airborne particulates (including metal flakes or particles) and reactive
gases acting alone or in combination with other environmental factors such as
humidity or temperature might pose a risk to the device that is described in this
document.
Risks that are posed by the presence of excessive particulate levels or concentrations
of harmful gases include damage that might cause the device to malfunction or
cease functioning altogether. This specification sets forth limits for particulates and
gases that are intended to avoid such damage. The limits must not be viewed or
used as definitive limits, because numerous other factors, such as temperature or
moisture content of the air, can influence the impact of particulates or
environmental corrosives and gaseous contaminant transfer. In the absence of
specific limits that are set forth in this document, you must implement practices that
maintain particulate and gas levels that are consistent with the protection of human
health and safety. If Lenovo determines that the levels of particulates or gases in
your environment have caused damage to the device, Lenovo may condition
provision of repair or replacement of devices or parts on implementation of
appropriate remedial measures to mitigate such environmental contamination.
Implementation of such remedial measures is a customer responsibility.
Contaminant
Limits
Particulate
• The room air must be continuously filtered with 40% atmo‐
spheric dust spot efficiency (MERV 9) according to ASHRAE
Standard 52.21.
• Air that enters a data center must be filtered to 99.97% efficiency
or greater, using high‐efficiency particulate air (HEPA) filters
that meet MIL‐STD‐282.
• The deliquescent relative humidity of the particulate contami‐
nation must be more than 60%2.
• The room must be free of conductive contamination such as zinc
whiskers.
Gaseous
• Copper: Class G1 as per ANSI/ISA 71.04‐19853
• Silver: Corrosion rate of less than 300 Å in 30 days
1
ASHRAE 52.2‐2008 ‐ Method of Testing General Ventilation Air‐Cleaning Devices for
Removal Efficiency by Particle Size. Atlanta: American Society of Heating,
Refrigerating and Air‐Conditioning Engineers, Inc.
2
The deliquescent relative humidity of particulate contamination is the relative
humidity at which the dust absorbs enough water to become wet and promote
ionic conduction.
3
ANSI/ISA‐71.04‐1985. Environmental conditions for process measurement and control
systems: Airborne contaminants. Instrument Society of America, Research Triangle
Park, North Carolina, U.S.A.