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December 17, 2015

Open Bath Immersion Cooling

Why Submer Went for a Single-phase Immersion Cooling

Open bath Immersion Cooling gif

‍Open bath Immersion Cooling is a Data Center cooling technique that implies fully submerging servers in dielectric coolant fluid. It’s called open bath because servers are placed side-by-side in large tanks that assimilate bathtubs. These baths operate at atmospheric pressure and allow the coolant fluid to be pumped through the hardware components or servers submerged in it. At Submer, we like to use the term “open bath” when talking about single-phase Immersion Cooling and “semi-open or closed” baths when talking about two-phase Immersion Cooling.

In single-phase open bath Immersion Cooling the dielectric liquid coolant always stays in liquid form (in contrast to the two-phase coolants that change state from liquid to gas and back). The coolant liquid is always in contact with the hardware installed in the bath and is pumped through the hardware towards the heat exchanging system that allows for the extraction of heat collected by the coolant. These heat exchanging systems usually convey with a water cooled circuit.

In comparison with two-phase Immersion Cooling, single phase open bath systems have these advantages:

  • Much cheaper to maintain
  • Much lower coolant costs
  • No issues with vapours and coolant evaporation

On the down-side the disadvantages basically are:

  • Removing the coolant from the servers is pretty tedious if you want to go back to air cooling operation (not likely).
  • The coolant circuit requires pumps to speed-up the convection effect and remove heat from the SmartPod to the heat exchanging system.

Currently, datacenter operations are all about cost, cost, cost. It costs money to develop, manufacture, house and operate a Data Center cooling solution. Less tangible environmental costs like greenhouse gas emissions, natural resource consumption and e-waste are becoming increasingly important to society. Immersion Cooling technology is able to have a dramatic effect on both financial and environmental costs in all stages of a server’s life cycle.

At Submer, we’ve chosen to build our first commercial SmartPod based on open bath single-phase Immersion Cooling. Our main aim is to provide a solution that is highly-efficient and cost-effective with the traditional Data Center in mind but also useful in HPC Clusters, Bitcoin mining and any other markets. All our efforts are focused on designing a solution that any and every datacenter can implement – both considering new datacenter construction or retrofitting into existing infrastructures. Our mission is to make Immersion Cooling the #1 datacenter solution by delivering unprecedented PUE’s and environmental benefits for the green datacenter wave.

A special thanks to Diarmuid Daltún