DCNN Exclusive: Making sustainability gains with liquid cooling

Author: Beatrice

This piece was written by Stuart Crump, Director of Sales at Iceotope Technologies Limited on how liquid cooling could be vital in the race to net zero.

Environmental, Social and Governance (ESG) objectives have started to drive data centre business goals as the world transitions to a low carbon economy. Sustainability is no longer being viewed as a cost on business, indeed many customers are now using sustainability as a criterion for vendor selection. Positive action to reduce emissions is not only good for the planet, it’s also good for business. It will also signpost efficient data centres to an enlightened market.

New developments in liquid cooling can assist data centre sustainability targets by significantly reducing facility energy consumption for mechanical services, decreasing water use, and providing a platform for high-grade reusable heat. Together, the characteristics of liquid cooling adds up to bottom-line benefits as well as ecological advantages to data centre operators, helping deliver competitive advantage in this highly commercialised sector.

According to the IEA, data centres account for around 1% of global electricity demand. While data centre workloads and internet traffic have multiplied dramatically since 2015, energy use has remained relatively flat. However, demand for more digital services is growing at an astounding rate. For every bit of data that travels the network, a further five bits are transmitted within and among data centres.

Immersion liquid cooling can greatly benefit data centre sustainability by significantly reducing overall cooling energy requirements by up to 80%. Data centre operators and customers now understand that air-cooled ITE environments are reaching the limits of their effectiveness. 

As compute densities increase, the energy demands of individual servers and racks spiral upwards. Legacy air-cooled data halls cannot move the volume of cool air through the racks required by the latest CPU and GPU systems to maintain operating temperature. This means they must have a plan that includes liquid cooling if these sites are to remain viable.

Liquid cooling techniques, such as precision immersion cooling circulates small volumes of a harmless dielectric compound across the surface of the server removing almost 100% of the heat generated by the electronic components. The latest solutions use a sealed chassis that enables IT equipment including servers and storage devices to be easily added or removed from racks with minimal disruption and no mess.

Precision liquid cooling removes the requirement for server fans by eliminating the need to blow cool air over the IT components. Removing air cooling infrastructure from data centres also removes the capital expense of some cooling plant, as well as the operational costs of installation, power, servicing and maintenance.

Removal of fans and plant not only produces an immediate benefit in terms of reducing noise in the technical area, it also frees up useful space in racks and cabinets as well as in plant rooms. Space efficiency equates to either facilities which are smaller in physical footprint, or the ability to host larger numbers of high density racks. Importantly, precision liquid cooling provides futureproof, scalable infrastructure to meet the provisioning requirements of tomorrow’s workloads and storage needs,

Precision cooling and data centre water use

The media reports widely on the lack of clean water for irrigation and consumption in drought hit areas from around the world. However, what has sometimes been called the data centre’s ‘dirty little secret’ is the volume of potable water required to operate certain data centres. Many air cooled data centres need water and lots of it. A small 1MW data centre using a conventional air-cooling process can use around 25.5 million litres of water every year.

With mainly air-cooled processes, the data centre industry is currently consuming billions of litres of water each year. On the other hand, precision immersion liquid cooling consumes zero water in most cases and can be installed anywhere – including many existing data centres. The water in the cooling system, allowing for maintenance and water loop refreshes, can easily reduce data centre water use by more than 95%.

The benefit of all this hot air…

Creating a revenue generator from a cost item on the balance sheet is an ultimate dream come true. Currently, air cooled data centres eject heat into the atmosphere in the vast majority of cases. Liquid cooling techniques which capture and remove high-grade heat from the servers offers the capability to redirect this heat to district heating networks, industrial applications and other schemes. Using well established techniques this revenue stream, or sustainability project, could help to heat industrial sites and local facilities, such as schools and hospitals. 

Climate change, government intervention with emission standards and public and investor pressure has helped drive change in the wider data centre business outlook. Savings and new revenue streams that benefit the organisations sustainability credentials warrant a critical review of their cost/benefit. There is the opportunity for data centres to move away from previous notions of how data centres operate towards much greater efficiency and sustainable operations.