OPTIMISING EVAPORATIVE COOLING:
BALANCING ENERGY EFFICIENCY AND WATER
CONSUMPTION
Traditional air-based cooling systems in data centres,
which rely on mechanical chillers and air conditioning, are
notably energy-intensive. As data centre power densities
increase, these conventional systems demand even more
energy to manage the additional heat load, a challenge
exacerbated in warmer climates like Southeast Asia.
Evaporative cooling offers a more energy-efficient
alternative by utilising water evaporation to dissipate heat,
thereby reducing electricity consumption. However, this
method increases water usage, necessitating proactive
water management strategies to maintain environmental
sustainability. Implementing measures such as water reclamation, real-time monitoring to minimise water loss,
and sourcing alternative water supplies can optimise
overall energy efficiency while mitigating the
environmental impact associated with higher water
consumption.
WATER RECLAMATION:
ADVANCING TOWARDS WATER-POSITIVE
OPERATIONS
In the pursuit of sustainable operations, data centres are
increasingly adopting water reclamation strategies to
achieve water-positive status — returning more water to
the environment than they consume. By sourcing and
treating non-potable water, such as municipal wastewater,
for cooling purposes, these facilities significantly reduce
their reliance on freshwater resources.
Technologies such as membrane bioreactor (MBR),
ultrafiltration (UF), and reverse osmosis (RO) play a crucial
role in removing contaminants, dissolved solids, and
microbial impurities, ensuring reclaimed water meets the
stringent quality standards required for data centre
operations. This treated water is then reused in cooling
towers and other processes, effectively closing the loop on
water usage.
By integrating reclaimed water into their operations, data
centres not only enhance environmental stewardship but
also bolster resilience against future water scarcity. This
commitment to water reclamation is a critical step toward
achieving water-positive operations, ensuring that these
facilities contribute positively to local water cycles while
maintaining efficient and reliable performance.
BALANCING SUSTAINABILITY AND COST:
OPTIMISING WATER MANAGEMENT EFFICIENCY
Efficient water management is essential for data centres
striving for sustainability while maintaining cost
effectiveness. Partnering with experienced solution
providers ensures the execution of large-scale water
reclamation projects, optimising both performance and
long-term savings.
Since 1996, Suntar has provided filtration, separation, and
purification solutions for water and wastewater treatment.
Specialising in advanced membrane technologies, the
company offers membrane solutions tailored to modern
water challenges.
Suntar’s advanced membrane-based solutions, including
graphene-enhanced polyvinylidene fluoride (PVDF)
membranes, set a new benchmark for wastewater treatment. With resistance to fouling, these systems
maximise water reuse without the need for additional RO
concentrate treatment. This not only enhances operational
efficiency but also keeps costs competitive, with operating
expense ranging from US$0.30-$0.40/m³, depending on
system capacity.
Designed for flexibility, Suntar’s systems can switch
between treated effluent and groundwater sources,
ensuring uninterrupted water supply even during
disruptions from sewage treatment plants (STPs). Suntar
implements an n+1 redundancy strategy, securing
continuous operation for water treatment processes and
cooling water supply.
Suntar’s membrane technology delivers high-quality
permeate water that meets stringent cooling requirements
at 80% water recovery rate, while ensuring all discharged
water complies with discharge regulations. This holistic
approach not only aligns with environmental and
regulatory standards but also supports data centres in
achieving long-term sustainability without compromising
performance.
GRAPHENE MEMBRANE SOLUTIONS FOR
SUSTAINABLE COOLING
Suntar’s graphene hollow fibre membranes combine
enhanced permeability, durability, and anti-fouling
properties. By leveraging graphene’s mechanical stability,
these membranes not only achieve superior filtration
performance but also reduce energy consumption by
having low filtration resistance and transmembrane
pressure differences in water treatment processes. Their
high tensile strength ensures long-term operational
reliability, while the hydrophobic groups on the graphene
surface minimise membrane fouling via repelling
hydrophilic pollutants, reducing the frequency of chemical
cleaning and maintenance.
The increased water flux — 1.5-2 times higher than
conventional membranes, translates into more efficient
water purification with lower operational costs. This
efficiency makes graphene hollow fibre membranes
well-suited for industrial and municipal water reclamation
applications.
Suntar’s proposed data centre water solution involves
treating wastewater through biological treatment,
graphene hollow fibre membrane bioreactors (Graphene
MBR), and RO to produce high-quality cooling water. The
biological treatment process incorporates denitrification to convert nitrate into nitrogen gas, reducing total nitrogen
levels. Oxidation processes involving aerobic
microorganisms further lower biochemical oxygen
demand (BOD), chemical oxygen demand (COD), and
ammonia levels.
The Graphene MBR system replaces traditional secondary
sedimentation in activated sludge processes. By
combining biological activity with membrane separation, it
enhances solid-liquid separation efficiency and supports
higher mixed liquor suspended solids (MLSS)
concentration, improving biological treatment
performance. With water quality post-MBR, the RO system
experiences a lower load, enabling higher recovery rates.
The RO concentrate is then discharged safely in
compliance with country-specific regulations.
This biological treatment and Graphene MBR combination
allow for an efficient, small-footprint system capable of
producing permeate with low suspended solids, BOD, COD,
and nitrogen-related components — meeting cooling
tower water quality requirements. The higher recovery
reduces required feed flow, alleviating stress on local water
sources.
THE FUTURE OF WATER USAGE IN DATA
CENTRES
As data centres continue to proliferate globally the focus
on sustainability has cantered around energy consumption
and efficiency However water usage is an equally critical
aspect Innovative solutions such as Suntar’s Graphene
MBR technology are paving the way for more sustainable
water management in data centres.
“Our graphene MBR technology provides a breakthrough
in sustainable water solutions for data centres offering
filtration efficiency with lower energy consumption” Dr Lan
Yihong executive director of Suntar said“ Suntar secured a
project in late 2024 to design a 20,000m³/day water
reclamation plant WRP supplying water to a data centre
client in Malaysia By optimising water reuse while
maintaining an operating expense of US$0.30-$0.40/m³ we
ensure that sustainability does not come at the cost of
economic viability”.
As the industry pushes towards net-zero and
climate-positive goals the next frontier in sustainability will
be ensuring that every drop of water is used wisely
responsibly and efficiently