Immersion Cooling

Immersion cooling is a technique for cooling IT equipment that consists of submerging the computer components in a thermally conductive and dielectric liquid. Through this practice, servers are cooled, and heat is transferred directly from the source to the liquid.

When talking about immersion cooling, we need to consider the different types of immersion cooling, as well as the applications of immersion cooling. This method has a multitude of benefits, especially environmentally-wise as it enables datacenters to be managed in a greener and more sustainable way. In recent years, environmental concerns have been a huge catalyst for the adoption of this technology.

At Submer, we believe in green datacenters powered by single-phase immersion cooling. Below you will learn more about immersion cooling and its benefits – whether you are new to the technique or consider yourself a pro, read on to discover something new!

The Basics of Immersion Cooling

To better understand what immersion cooling can do for datacenters, we need to clarify what immersion cooling is, why we should apply immersion cooling, and how the technology works.

What Immersion Cooling Really Means

As we just mentioned, immersion cooling is a method that is becoming increasingly popular with innovative datacenters... but what makes the technique so popular and what differentiates it from the rest?

So, Why Immersion Cooling?

Immersion cooling could be the smart choice from both an operations point of view and a practical perspective.

Immersion cooling simplifies datacenter commissioning.

It makes datacenter maintenance easier.

Deployment is fast and straightforward.

Furthermore, immersion cooling for datacenters makes sense from an environmental perspective: an area that is of increasing concern for the industry.

According to the European Commission, in 2020 data centers consumed about 2% of the world’s electricity. By 2030, is expected this percentage is expected to grow to up to 8%.

The U.S. Environmental Protection Agency estimates that 28% of the water use in office buildings is for the cooling and heating system.

In what we consider a conventional datacenter, the amount of potable water consumed per year is up to 464,242,900.6992 litres.

The Benefits of Immersion Cooling

The practice of immersion cooling has a huge number of benefits, especially when it comes to sustainability and efficiency. Why is this important? These are two of the biggest challenges that the industry must overcome, both now and in the future. Immersion cooling significantly reduces the amount of water used, levels of carbon emissions, and much more. 

Immersion cooling is scalable and modular

Overcome the challenges of space and scalability by implementing Immersion cooling within your infrastructure.

Immersion cooling can help to reduce the carbon footprint of your datacenter

Traditional datacenters use a high amount of fossil fuels to help power their cooling systems. Immersion requires significantly less power to run and to cool the IT servers and equipment, significantly reducing the amount of CO2 produced. 

Immersion cooling can help to improve your efficiency and reduce the use of natural resources

A smart datacenter should be able to tap into clean and renewable energy sources. By using immersion cooling, you are able to utilize high-power computing that is resilient and secure, without putting a strain on the environment. At Submer, we harness the power of single-phase immersion cooling to enable our customers to turn their potential burden on the environment into a benefit.  In March 2020, Submer announced the installation of 10 SmartPod units delivering up to 500kW of heat dissipation at a neutral datacenter BitNap  (Barcelona, Spain). This is the first sustainable liquid immersion cooling cluster in Spain to rely on renewable energies as a secondary cooling system, BitNAP is a part of the district heating and cooling (DHC) system operated by Ecoenergies.

“This is the first of many examples to come of real symbiosis between datacenters, renewable energies, smart technology and a truly viable industrial application”.

Daniel Pope

Co-founder and CEO of Submer

How Immersion Cooling works

How does the immersion cooling system work? When choosing an immersion cooling system, servers are totally submerged in the dielectric coolant, but for this to happen, there’s an infrastructure in place. As the electronic components generate heat during operation, the coolant comes into direct contact with them. The heat from the components is transferred to the coolant through conduction.

Types of Immersion Cooling

The main options for datacenter cooling are air conditioning, direct to chip, and liquid cooling. Depending on the technique chosen, datacenters will be better or worse equipped to face challenges in terms of performance, density, efficiency, space, and sustainability. 

At Submer we are most interested in liquid cooling since we believe that this is the best way to achieve higher levels of efficiency.

There are a few different types of liquid cooling (immersion cooling included). There are two different methods of immersion cooling on the market: Single-Phase Immersion Cooling and Two-Phase Immersion Cooling. So, what are the differences between single-phase and two-phase immersion?

Single-Phase Immersion Cooling

  • Single-phase coolant never changes state, it never boils or freezes and always remains in a liquid form
  • Easier to access
  • Does not require a high level of maintenance

Two-Phase Immersion Cooling

  • In two-phase cooling, the working fluid boils and thus exists in both a liquid and gas phase
  • Complex to access
  • Requires more maintenance

Submer solutions are based on single-phase immersion cooling. The main reason we chose this technique is that it better aligns with our core values of sustainability and having a positive impact on the environment. How? Single-phase immersion cooling uses a biodegradable, non-toxic, non-flammable, non-corrosive liquid that has a lifespan longer than the average life of many datacenters. 

Immersion Cooling: The Fluid

The reason behind why immersion cooling is more efficient than air cooling is, among others, because of the fluid. Why? The liquid is the key to how the heat is conducted. The choice of liquid is fundamental if the full benefits of immersion cooling are to be achieved. 

Dielectric fluids are typically based on hydrocarbon compounds. The compounds can be from vegetable oils, mineral oils, fluorocarbons or other synthetic fluids. Dielectric liquids are classified depending on whether they are used within single-phase or two-phase immersion cooling.

What Type of Fluid is Best for Immersion Cooling?

The following 5 questions will help you to understand which liquid is the most appropriate one for you:  

  • Which of these liquids will be compatible with my IT hardware?
  • Which will be safe and easy to work with?
  • Which one has the longest life-span?
  • Will the liquid impact the environment in the future?
  • Is there any difference in the cooling performance depending on the liquid?


After exploring all the fluids that the market had to offer, we decided to take matters into our own hands and create our own dielectric fluid. The SmartCoolant is our Goldilocks solution to the immersion cooling problem and is designed using our hands-on experience designing immersion cooling systems.

Below is a live demo of our SmartCoolant. See Dr Peter Cooper (PhD), our Chemical Engineer, and Daniel Pope, our CEO, using a blowtorch to illustrate how our SmartCoolant is truly non-flammable. To better understand the key differences between dielectric fluids, how the fluid works, and everything you need to know about it, click here.

Differences With Other Cooling Techniques 

Until now, most datacenters have used air cooling to regulate the temperature of the IT equipment. However, recent studies have shown that air cooling is no longer a viable technique to keep up with the demands of the needs of modern datacenters. This has left many searching for alternative techniques, Immersion cooling presents a compelling argument thanks to its ability to offer users high-densitylow latency and higher levels of efficiency and sustainability in comparison to air. Let’s take a look at some of the other key differences and advantages immersion cooling can offer. 

Submer vs other cooling technologies

Did you know that immersion cooling is more efficient than traditional cooling technologies…?

  • 1,400 times better thermal conductor than air
  • > 40% less TCO*
  • 8 times less electrically conductive than air

Single-phase Immersion Cooling vs Air Cooling

  • Significant energy savings
  • Avoid exponential costs of server overhaul
  • No risk of catastrophic damage to IT HW

Single-Phase Immersion Cooling vs Direct to Chip

  • Turnkey solutions
  • Scalable technology
  • Sustainability & ESG at its core

SUBMER vs Immersion Cooling Competitors

* $ Total Cost of Ownership SmartCoolant:
he = 2050 W/m2K
Air: he = 10 W/m2K

As you can see, immersion cooling is a very good option to help datacenters solve the challenges that they currently face and also to ensure that it is set up to deal with any challenges it may face in the future.

If we plan to improve datacenter capabilities in order to achieve more density but also efficiency is something we can achieve by using immersion cooling. That’s a good advantage if we compare immersion cooling with other techniques. In this 2-minute video, we discover the secrets to increase the power density of your datacenter through Submer’s technology vs air-cooled racks.

Immersion Cooling Applications

The applications of immersion cooling are vast and spread across many different industries. From smart cars, agriculture, high-frequency trading, or cybersecurity, if the task requires high-power computing that is fast and has low latency, it is likely that you will benefit from Immersion cooling. Here is a list of other popular applications that would benefit from Immersion cooling: 

Medical record storage


Language learning

Customer service



At Submer we have created a range of solutions to take the hassle out of choosing the perfect solution for your needs. Targeting four key industries ( HPC, AI/ML, Cloud and Edge), our solutions have been designed to maximize internal footprints and achieve industry-leading operational and energy efficiency through immersion cooling. The solutions are powered by Submer’s industry-leading Immersion technology which empowers users to have high-density compute environments while simultaneously reducing their impact on their environment and increasing levels of sustainability. 

Immersion Cooling: The Products

Our Immersion cooling products are part of our ‘Submer Cools‘ brand. We have designed a range of modular solutions that empower users to effortlessly scale their operations while simultaneously saving space and energy and increasing compute capacity. Currently, there are three core products, available in a variety of sizes allowing us to cater to every company’s specific needs and requirements. 

SmartPod EVO

The SmartPod EVO is the latest evolution of our flagship product and the easiest path to immersion cooling. This compact solution is the perfect solution for plug & play immersion at scale. Packing 140 kW+ of heat dissipation capacity, the SmartPod EVO does so while reducing your environmental footprint. Choose between single or dual CDUs for optimal performance. Key benefits of the SmartPod EVO include: 

  • Efficiency and sustainability 
  • Ease of deployment  
  • Smooth and predictable daily IT operations 


The MicroPod is our Edge-ready datacenter in-a-box. Built specifically to target the increasing needs of companies that need to bring their infrastructure closer to the customer such as telecommunications, streaming, or cloud computing. Purpose-built to be extremely flexible and modular, the MicroPod has integrated secondary cooling and up to 7kW of heat dissipation. Be it a warehouse, office building, in the heart of a city or in a remote area with harsh-climate conditions and far from the grid, the MicroPod will be fit for the job.
Other benefits of the MicroPod include:

  • Low energy footprint
  • Reduction of Total Cost of Ownership (TCO)
  • Zero water consumption
  • Increase hardware lifespan
  • Dramatic OPEX reduction


  • Deru, M., & Bonnema, E. (2019, 16 agosto). Testing and Evaluation of a Chemical-Free Cooling Tower Water Treatment Technology. Osti.Gov.
  • EU Eyes Carbon-Neutral Data Centers by 2030 in Green-Tech Switch. (2020, 6 febrero). Data Center Knowledge.
  • Mezzanotte – Pr, M. C. \. C. M. V. B. S. (2020, 8 septiembre). Submer: When Datacenters really Start to Make Sense. Data Center Knowledge.
  • Qin, Y. (2020). Micro-Manufacturing Engineering and Technology. Sciencedirect.Com.