Rittal Liquid Cooling Package
51
9 Operation
EN
9.2.4
Automatic door opening, LCP Rack
In conjunction with the LCP cooling systems, the auto-
matic door-opening feature may be appropriate under
certain conditions. With this feature, the doors of the
systems are kept closed under normal circumstances
and are opened, if necessary, by a mechanism.
Possible reasons for use:
Fire extinguishing
Whole-room fire extinguishing systems are already in-
stalled in many existing data centres. However, when
rack-based, high-density cooling is used in closed en-
closures, the extinguishing gas cannot penetrate into
the inside of the rack in the event of a fire. If the doors
are automatically opened when needed, the extin-
guishing gas can flow into the enclosure.
Emergency cooling
In principle, redundancy with respect to cooling can
be achieved with the alternating installation of LCPs
and racks (fig. 18). If this type of installation is not pos-
sible, the internal temperature of the enclosure can
rise considerably within a short period of time, e.g. if
the cooling water supply fails (e.g. at a heat loss of
15 kW, the temperature will rise from 22 °C to 32 °C in
approx. 90 seconds). However, the rise in the air in-
take temperature depends greatly on how leak-tight
the server rack is.
Emergency cooling can be achieved by the automatic
door opening feature. However, the installation loca-
tion must have adequate air conditioning.
Automatic door opening can be effected in several
ways, as follows:
Perforated server rack front door in conjunction
with a glass or sheet steel enclosure rear door
If the need arises, only the rear door of the enclosure
is automatically opened. The air flows into the interior
of the enclosure via the perforated front door, circu-
lates around the installed equipment and exits the
system via the open rear door of the enclosure. It is im-
portant to ensure that the LCP fans are switched off,
otherwise hot air will be blasted in front of the
482.6 mm (19") level in the event of emergency cool-
ing.
If this variant is used, whether for fire extinguishing
purposes or for emergency cooling purposes, the in-
stallation room must be air-conditioned (ASHRAE con-
ditions, 22 °C, 50% rel. humidity). If this method is
used for emergency cooling, even higher heat losses
in the server rack can be dissipated.
With this method, the escape route is only blocked at
the back of the server rack. Unauthorised access, is
however, possible through the open rear door. The
separate partition between the cooling system and the
rack is eliminated.
