14 July 2004
Including changes 12 April 2005
Designer must base the cooling load calculations upon the actual
equipment to be installed, if known; see Tables D-1, D-2, and D-3. If actual
equipment is unknown, base load calculations on not less than one Type "SIDF1"
equipment rack for NMCI (Table D-3 Cabinet SIDF1 = 3728 BTU/HR). If co-
located Telecom equipment (such as Telephone racks & switches, Fire alarm
panels, and Intrusion Detection Systems) is to be present, consider it equivalent
to not less than one Type "SIDF2" equipment rack (Table D-3 Cabinet SIDF2 =
5170 BTU/HR). These loads do not include the infrastructure loads such as
lighting and other equipment located within the NMCI/Telecom spaces.
Calculate the cooling load on the design cooling day, and the
heating load on the design heating day, without the surrounding rooms being
conditioned, as though on an extended weekend shutdown of the remaining
building systems, similar to a 3 or 4 day holiday period. Further, size the heating
system to maintain the design minimum temperature without the NMCI/Telecom
Cooling capacity must be adequate to cover the completely built-
out space with a + 10% margin.
Existing building cooling is acceptable, provided the system is
capable of preventing the NMCI/Telecom equipment from overheating in the
event of a commercial power interruption. Air systems such as variable air
volume units are also acceptable to meet cooling requirements. An EDS-
provided independent cooling system for the POP equipment space is an EDS
choice of last resort. The power requirements for the air conditioning equipment,
when provided by EDS, are included in the electrical loads in Appendix D. Note:
If cooling shuts off and power stays on, NMCI equipment must be
cooled. The redundant A/C units or ambient exhaust ventilation
must be sufficient to offer adequate cooling.
If power shuts off, NMCI equipment will shut off once the UPS is
The ambient temperature will be measured 1.5 m (5 ft) above the
floor level, after the equipment is in operation, at any point along an equipment
aisle center line. (ANSI / TIA / EIA 569-A, Section 8, paragraph 22.214.171.124.3).