Specifications

6
Glossary Of Terms
Adaptive Architecture
Liebert Adaptive Architecture
Liebert Adaptive Architecture is a
family of products and technologies
that demonstrate the ultimate in
flexibility while balancing the
importance of minimal TCO and
high availability.
Open Architecture / Closed
Architecture
Open architecture is a cooling
method that utilizes cooling coils
and room air volume as a thermal
storage to ride through power
outages.
Closed architecture fully encloses
the rack with the cooling coils inside.
Other provisions are required for
power loss ride-through.
Redundancy
Level to which a system can sustain a
failure or be serviced while
continuing to provide 100% of the
product's intended function.
Systems with no redundancy may
stop functioning when any single
component fails or maintenance is
required.
Redundancy can be achieved by
paralleling components, where at
least one of the components is
extra and not required for the
system to provide 100%
functionality. This design prevents
major component failures or
scheduled maintenance from
affecting the performance of the
product. This configuration can
provide very high systems
availability.
The highest levels of redundancy
are achieved by installing two
independent systems, preferably
with isolated input and output
paths. Preventive maintenance or
any component failure has no
affect on system performance
because the second system is
capable of providing 100% of the
product's intended function.
Industry Terms
Availability
When a proven technology or
system design minimizes single
points of failure or downtime in
your IT systems.
Business-Critical Continuity
The promise that our
customers’ technology
infrastructure will not go down
and bring their businesses to a
standstill.
Flexibility
Products or systems that can be
reconfigured or added to meet
the demands of new
technologies, achieve higher
protection results and adapt to
growth/changing business
requirements.
Total Cost Of Ownership
Cost evaluation based on sum
of equipment purchase, future
changes, and service costs.
Power
Power – Three Phase
A three phase circuit consists of
three phases, ground and in some
cases neutral. Typical three phase
voltages are 208V, 480V and 600V.
Three phase voltages with neutral
are 208/120V, 480/277V and
600/347V.
Power – Single Phase
Single phase circuit is a two-wire
circuit with ground. Typically 120V
or 208V.
Power Density
More power. More heat. Less space.
With the increase of processor
capabilities within smaller spaces,
power densities will also rise
(sometimes from 50Watt per s.f. to
over 300Watt per s.f.). This makes
your data center hotter, at times
creating localized “hot spots.”
UPS Type –
On-line or Line-Interactive
An online UPS is used in the
protection of critical applications
and consists of a continuous flow of
power that protects from all power
disturbances, including subtle
harmonics and waveform
distortion. A line-interactive UPS
offers protection to ride out “dirty”
power. This energy-efficient
technology provides both power
conditioning and battery back-up
and is particularly effective where
outages are rare, but power
fluctuations are common.
Battery Capacity
The percentage of power you get
from your batteries, attributed to
age, usage, environment,
temperature and maintenance. A
typical VRLA battery may reach
80% capacity and need
replacement within 3-5 years.
Battery Runtime
The le
n
g
th o
f time (min
u
tes) your
ba
tt
e
r
i
e
s will back-up and protect
y
o
ur in
f
or
m
ation during a power
o
u
t
a
ge or s
y
stem failure.
Cooling
Heat Rejection
Countering the increase of heat with air-
cooled condensers and drycoolers for any
ambient temperature or altitude. Hot air
and water are removed, and the water is
cooled and recycled.
Precision Cooling
The accurate controlling and regulation of
temperature, humidity and air filtration.
Hot Aisle / Cold Aisle
A highly recommended method of
improving performance of existing raised
floor cooling technology in high density
rack-based applications. Rows of
equipment racks are arranged in
alternating “hot” and “cold” aisles. Only
the cold aisles have perforated floor tiles
that allow cool air to come up from under
the raised floor.
Sensible Heat
Sensible heat is heat that can be felt or
measured. It is the heat that causes a
change in the temperature of a substance.
Think of it as the temperature that the
weatherman gives. It can be measured by
a thermometer. Servers give off strictly
sensible heat.
Latent Heat
Latent heat relates to the heat energy
absorbed in the process of changing the
form of a substance. In the air-
conditioning cooling process, latent heat
removal is the condensation of vapor in
the air when it is cooled below its dew
point (dehumidification). Removing latent
heat does not affect the actual
temperature that you feel.
Total Heat
Total heat is the sum of the heat content
of the air (sensible heat) and the water
vapor mix (latent heat). It translates to the
rated capacity of the air-conditioner.
BTU
BTU is defined as the unit of heat quantity
required to change the temperature of
one po
un
d o
f w
a
t
e
r 1 degr
ee F
ahrenheit
a
t s
e
a le
v
e
l
. O
ne t
on of air-conditioning =
12,000 B
TU
s pe
r h
o
ur
.
C
ooling Tons
A t
on is the amount of heat removed by
an air c
onditioning system that would
melt 1 ton of ice in 24 hours. One
refrigeration ton = 12,000 Btu/h = 3,025.9
k Calories/h.