Submerged Server Cooling

Submerged server cooling, also known as liquid immersion cooling, is a data center cooling method that involves submerging of server components in a dielectric coolant. This coolant has a high coefficient of heat rejection and low thermal resistance, which ensures the protection of the IT components and overall equipment functions. This process is highly energy efficient because the liquid is a better conductor of heat than air. Air cooling also requires additional steps for the air to be both cooled and then blown directly at the heat source to be effective.

Mineral oil is the most common liquid used for submerged server cooling and cools as effectively as 1,200 cubic feet of air, requiring significantly less energy input. The more processing power a server has and the more power it consumes, the more beneficial it is to utilize submerged server cooling as it is cost effective and energy efficient. This is primarily attributed to the lack of fans needed for this technology which drastically decreases power usage.

Types of Submerged Server Cooling

Submerged server cooling can be further divided into two types of techniques depending on the properties of the coolant used. The optimal submerged server cooling is dependent on the density of the servers as well as the costs willing to be paid by data center managers. The two types of submerged server cooling include:

• Single-phase immersion cooling. With single-phase immersion cooling, the state of the liquid coolant remains the same, and it never freezes or boils to become a solid or a gas. The coolant is pumped into a heat exchanger where heat is transferred to a cooler water circuit. There is little to no risk of coolant evaporation, allowing the system to use an “open bath” technique with the coolant. The servers are installed vertically into the coolant bath, which consists of a hydrocarbon-based dielectric fluid similar to mineral oil. It is the simpler of the two submersion cooling options, making it more affordable and easier to maintain. However, it is not the optimal solution for high density racks as it has a lower cooling capacity than two-phase immersion cooling.
• Two-phase immersion cooling. Also known as evaporative cooling or flow boiling, two-phase immersion cooling involves the working fluid existing in both a liquid and gas phase. This system uses latent heat, which is the thermal energy required to change the phase of a fluid. Energy is transferred from the heat source to the fluid, causing the fluid to boil and turn into a gas. The gas rises above the fluid pool and comes into contact with a condenser that turns the gas back into a liquid and flows back into the pool. This type of submerged server cooling is most ideal for high density racks as it has a higher cooling capacity, but it is more expensive and potentially harmful to the environment.

Cool Your Data Center Efficiently with DCIM Software

Data Center Infrastructure Management (DCIM) software collects, reports, and alerts on data from power and environmental sensors to ensure that the data center is being cooled efficiently.

Key aspects of DCIM software that contribute to a more efficient cooling system include:

• Measuring and monitoring data center energy consumption for more intelligent management decisions for the facility
• Environment monitoring to better understand the current conditions and determine what areas need improvement
• Tracking power, environment, energy, and cost data in real-time to monitor the impact of data center energy efficiency initiatives on KPIs
• Data center automation capabilities, zero-configuration charts and reports, and visual analytics that aid in reducing energy consumption

Want to see how Sunbird’s world-leading DCIM solution can help you efficiently cool your data center? Get your free test drive now!