scope:

OVERVIEW

Environmental requirements of datacom equipment may vary depending on the type of equipment and/or manufacturer. However, there has been agreement among a consortium of manufacturers on a set of four standardized conditions (Classes 1- 4). These conditions are listed in the ASHRAE publication Thermal Guidelines for Data Processing Environments (ASHRAE 2009). An additional classification, the Network Equipment-Building Systems (NEBS) class, is typically used in telecommunications environments. Definitions of all classes are provided below:

• Class 1: Typically a datacom facility with tightly controlled environmental parameters (dew point, temperature, and relative humidity) and mission critical operations; types of products typically designed for this environment are enterprise servers and storage products.

• Class 2: Typically a datacom space or office or lab environment with some control of environmental parameters (dew point, temperature, and relative humidity); types of products typically designed for this environment are small servers, storage products, personal computers, and workstations.

• Class 3: Typically an office, home, or transportable environment with little control of environmental parameters (temperature only); types of products typically designed for this environment are personal computers, workstations, laptops, and printers.

• Class 4: Typically a point-of-sale or light industrial or factory environment with weather protection, sufficient winter heating, and ventilation; types of products typically designed for this environment are point-of-sale equipment, ruggedized controllers, or computers and PDAs.

• NEBS: According to Telcordia GR-63-CORE (Issue 2, April 2002) and GR- 3028-CORE (Issue 1, December 2001), typically a telecommunications central office with some control of environmental parameters (dew point, temperature, and relative humidity): types of products typically designed for this environment are switches, transport equipment, and routers.

• Since Class 3 and 4 environments are not designed primarily for the datacom equipment, they are not covered further in this chapter, and reference should be made to ASHRAE's Thermal Guidelines book for further information (ASHRAE 2009).