FEATURE
An adiabatic V cooler
IT IS VITAL
THAT WATER
CONSUMPTION
RATES ARE
TAKEN INTO
ACCOUNT
NOW, IN ORDER
TO PREVENT
EXPENSIVE
REPLACEMENTS
FURTHER DOWN
THE LINE.
In terms of EER, this difference
translates as an approximate EER of
4 (4kWth/1kWe) for a conventional
compressor solution and an impressive
EER of around 75 (75kWh/1kWe) for the
equivalent ambient cooling solution.
This of course, translates to substantial
energy and cost savings for energy-
hungry mission critical environments.
But let’s concentrate on the water
consumption. Given that cooling towers
rely on evaporative cooling throughout the
year, achieving little to no sensible cooling,
and hybrid systems begin to evaporate
water in ambient temperatures as low as
10°C, it will be no surprise that adiabatic
coolers consume less than 1% of the
water used by traditional cooling towers
and approximately 2–4% of that used by
wetted surface hybrid coolers.
Even when operating in wet mode, adiabatic
systems automatically vary the amount of
water used to minimise consumption whilst
still hitting required water temperatures in
varying ambient conditions.
If we examine those figures more
closely, as water consumed in cubic
meters over a one-year period for
a 1000kW unit, an adiabatic cooler
consumes 92 m³of water, compared to
a wetted surface hybrid cooler which
requires 8,647 m³ and a conventional
42
Issue 01
cooling tower which is more in the
region of a staggering 18,220 m³. innovate technologies which preserve
both power and water.
Latent heat of evaporation dictates that
for every kW of heat that a cooling tower
dissipates it must evaporate 1.6kg of water. Without a doubt, water is more
abundant here in the UK and for the
next few years, the importance of water
conservation isn’t likely to reach critical
levels for us.
On top of this, in order to stop cooling
tower base tanks from being clogged
with the residual scale left over from the
evaporation process, an additional amount
of water must be bled off and replenished
from a mains water supply.
Depending on how hard the water is,
this can add an additional 20% to 100%
water consumption on top of the water
evaporated. At a typical 30% increase this
means that the total water consumed is
2.08kg per kW of cooling.
But when specifying water-consuming
plant designed to last in excess of a
decade, it is vital that water consumption
rates are taken into account now, in order
to prevent expensive replacements further
down the line, when the government
inevitably regulates water consumption in
the data centre market. ◊
For a typical 1,000kW cooling system this
gives a cooling tower water consumption
of 2,080kg every hour. In contrast,
adiabatic coolers, designed with water
conservation in mind, would typically
consume 350kg every hour and only for 3%
of the year rather than 100% of the year.
Water-conscious specification
Specifiers, whether working on a large-
scale data centre project or a smaller
facility can uphold their moral obligation
by working with manufacturers who
Tim Bound, Director for Transtherm
Cooling Industries
www.intelligentdatacentres.com