According to the International Energy Agency's (IEA) annual electricity report, data center energy consumption is expected to rise and by 2026data centers will have consumed over 1000 TWh of electricity worldwide, In 2022, data centers consumed 460 TWh of electricity.

The development of modern IT hardware that can deliver greater computing capacity, and the widespread adoption of advanced data analytics technologies, artificial intelligence, and machine learning, etc. are major drivers of this incremental expansion.

The utilization of the liquid cooling technique presents a viable answer to this issue, offering contemporary approaches for cooling data center infrastructure more efficiently and sustainably. Datacenter providers can reduce their overall operating costs and allow infrastructures to run at greater temperatures with higher power densities by utilizing the liquid cooling approach.

Liquid cooling technology

Using various liquid arrangements to maintain appropriate temperature levels in data centers is known as liquid cooling technology. This type of cooling is more effective than the conventional air-cooling approach. This method produces more effective cooling results overall since liquids carry heat more effectively than air does.

Multiple types of liquid cooling methods are in use. A few of them are:

Direct liquid cooling: This method circulates the liquid to the CPU or GPU, uses a heat exchanger to remove heat from the heated liquid, and then returns the liquid to the equipment.

Immersion cooling: IT equipment is immersed in a non-conductive liquid (not water) to remove heat and dissipate heat in a 50℃-operating environment after that, the liquid is cooled by passing through the heat exchanger.

Dual-phase immersion cooling: In this method heat will be transferred from IT equipment to the flowing liquid and then change its state to gas and as soon as gas rises above the liquid pool condenser again changes its state back to liquid. 

Two-stage evaporating cooling: This method is also known as direct / Indirect cooling, there are pads in which water can be supplied and when this water evaporates temperature of the surrounding air also drops and this air is sent to lower the temperature of Datacenter. Water that will drip from the pads gets collected at the bottom of the chiller and again sent to the pads. This technology is majorly effective in dry climates.

Closed coupled cooling: In this method equipment rack and cooling system are placed very close to one another to reduce overall energy consumption and it provides more effective results as compared to other cooling techniques by reducing the overall gap between infrastructure and cooling systems.

Benefits of liquid cooling technology

1. Reduction in space constraints: By implementing liquid cooling techniques DC operators can accommodate performance or power-heavy equipment together which can reduce overall space requirements which were not achieved in traditional data centers. For example, in traditional DCDCs, there is a throttling of supplied power in equipment racks and a large amount of space remains unserved; however, =in liquid cooling driven DC’s, these equipment racks can accommodate with their full capacity and able to cater required power density.
2. Cost-effective:  By implication of liquid cooling, overall energy cost of DC can be reduced to a larger extent as liquids have higher thermal conductivity than air and by this technique, there will be less energy consumption required for cooling which reduces energy cost associated with the same. This technique gives long-term cost benefits while initial investments in setups can be higher than traditional ones.
3. Bolstering sustainability: Liquid cooling systems consumes less operational energy and boosts the efficiency of overall infrastructure which in turn gives rise to sustainable operations and less carbon emissions. This is very important in current scenarios where computing power demands rise with the adoption of AI / ML, HPC, advanced data analytics, etc.
4.  Noise reduction: Liquid cooling systems are quieter than traditional Air-cooling systems which have fans that produce continuous noise, although in some liquid cooling systems to cool radiators there will be fans that run at slower speeds.
5. Operational control: The liquid cooling system can be directed to specific areas where cooling is required and to specific infrastructure in use which reduces overall energy consumption.

6. Enhance infrastructure performance: In a liquid cooling system, there is no throttle for equipment running to temperature as this system removes heat more efficiently so equipment can perform at its maximum levels which effectively increases the efficiency of overall operations and delivers higher performance.

   Liquid cooling systems will replace traditional cooling systems as they deliver more efficient ways of cooling and reduce overall data center facility Power Usage Effectiveness (PUE) and Total Usage Effectiveness (TUE) by consuming lesser operational power and giving rise to more sustainable ways of cooling overall data center facility.

How can liquid cooling complement the sustainability objectives of data center operators? 

1. Energy efficiency: In general, liquid cooling solutions use less energy than conventional air-cooling techniques. Through the effective removal of heat from servers and other equipment, liquid cooling can cut a data center's overall energy consumption and help achieve sustainability goals by lowering energy expenses and carbon emissions.
2. Heat recovery: Certain liquid cooling systems collect and repurpose the surplus heat produced by servers for applications like hot water delivery or space heating. By lowering the data center's dependency on traditional heating sources and increasing its energy efficiency, this heat recovery technology can help sustainability objectives.
3. Space optimization: Higher-density computing architectures are frequently made possible by liquid cooling technologies, which help data centers maximize their floor area and fit more equipment into the same footprint. Due to its potential to minimize environmental impact, this space optimization can result in lower land use and building material use, which is consistent with sustainability standards.
4. Water efficiency: Even though liquid cooling systems utilize water as a coolant, they may be made to run as efficiently as possible, using less water overall. Cutting-edge liquid cooling techniques, like water recycling and closed-loop systems, can lessen the water footprint of data centers and lessen their negative effects on nearby water resources.
5. Renewable energy integration: Data centers that use liquid cooling are ideal for integrating renewable energy sources like solar or wind power. center data center providers can further improve their environmental credentials by shifting away from fossil fuels and toward more sustainable energy sources by combining liquid cooling with renewable energy generation.
6. Lifecycle sustainability: Through more efficient cooling and thermal management, liquid cooling solutions can extend the lifespan of hardware components, thereby contributing to the overall lifecycle sustainability of data centers. Throughout time, liquid cooling systems can assist in minimizing electronic waste and resource consumption by lowering the frequency of equipment upgrades and replacements.

All things considered, data center operators can increase the sustainability of their operations by utilizing liquid cooling technologies to optimize space utilization, reduce water consumption, increase energy efficiency, and integrate with renewable energy sources. DC providers can show their commitment to environmental responsibility in the digital age and align with sustainability initiatives by integrating liquid cooling into their infrastructure strategies.

To know more, you may write to us at HCBU-PMG@hcl.com. 

Reference: Electricity 2024 – Analysis - IEA ( IEA Report 2024)