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July 24, 2023

How to Apply Heat Reuse in Your Datacenter  

Tap into your datacenter’s unused potential

How to apply heat reuse in your datacenter

What if we told you that heat reuse doesn’t just efficiently utilize the incredible amount of waste heat your datacenter is already producing, but is also a way of unlocking new revenue streams and being kinder to the planet?

In the world of data centre cooling, heat has long been the enemy; the more powerful our computer chips grow, the more the cooling of components becomes a bigger and more complex issue. While the industry is making strides by using green power to fuel its operations, a crucial step in the reduce, reuse, recycle mantra seems to be overlooked: heat reuse.

In this blog post, we explore how heat reuse with immersion cooling works, the applications it can be used for, and a use case showing this ground-breaking technology in action… Prepare to be inspired by this technology’s transformative potential! 

Typical Heat Removal 

Of course, IT hardware operations naturally generate a lot of heat. Immersion cooling transfers this heat to a coolant (dielectric fluid) in order to maintain an optimal operating temperature. For example, the IT hardware inside our tanks can operate at 55ºC / 131ºF (depending on server specifications).

How immersion cooling works

In a system without a heat recovery solution, the coolant’s heat needs to be extracted with secondary cooling.  

How the Heat Reuse Process in a Datacenter Works 

In a Heat Recovery System, the heat is deviated to a Heat Recovery Unit (HRU) which transfers the heat to the application process of your choice e.g., heating, hot water, radiant floor, etc. 

How heat reuse with immersion cooling works.

Depending on the application, different supply temperature requirements should be achieved. The HRU receives all the heat generated on the IT devices, and then, if needed, it can increase the supply temperature to the application requirement. 

Since the heat is being transfered to to another application, the secondary cooling unit wont need to work at 100%; therefore, there is a possibility for cases where all heat is reused and the cooling units don’t consume energy. 

What’s the HRU? 

The Heat Recovery Unit (HRU) is the equipment designed to guarantee optimal energy recovery for various applications. The unit’s size and configuration depend on the requirements of each individual project. 

The main components of an HRU include: 

  • Heat exchanger  
  • Pumping set  
  • Temperature optimizer 

Heat Reuse Applications 

Heat reuse systems are growing in popularity and the opportunity for new applications continue to arise. Below, we’ve compiled a list of applications and the water temperature range required for these to be successful.  

Heat reuse applications and the required water temperatures.

Heat Reuse in Action: A Use Case 

Let’s consider a use case in Ireland with an ambient temperature of -5ºC, powered by 24 of our SmartPod XL+s and based on a water-cooling loop.  

Reusing waste heat with immersion cooling.

The specific design conditions for this heat reuse use case were as follows: 

  •  24 SmartPods XL+ (50KW each)   
  • Ireland with an ambient temperature of -5ºC   
  •   Q = 6 m3/h (each)   
  •   Q total = 144 m3/h   
  •   Tw.inlet = 30 ºC   
  •   Tw.outlet = 37 ºC   
  • Tank SetPoint = 50ºC 
Heat reuse for datacenters with immersion cooling

Now, let’s take a look at the results we obtained:  

  • The pods generated a flow rate of 67m3/h, increasing the temperature of the application from 20ºC to 35ºC. 
  • If the heat exchanger reduces the return temperature to 30ºC, the dry coolers will not need to operate since the water supply to the pods should be 30ºC (for this particular scenario).  
  • If a higher temperature is required and the pods are providing a lower temperature, the Temperature Optimizer will adjust accordingly (depending on the case). 
  • In the case of a 35ºC outlet from the pods, and an scenario where a 35ºC should be provided for heat recovery, the temperature optimizer will need almost no energy to operate. 
  • If the supply temperature of the application is above the produced on the pods, the temperature optimizer will increase the temperature with the need for additional energy. 
  • The heat exchanger transfers the energy to reuse it in applications, improving efficiency.  
SmartPod use case results

Are You Ready for Heat Reuse? 

We’ve explored the incredible potential of heat reuse with immersion cooling, uncovering how this innovative technology can transform datacenters into more sustainable and efficient operations. By tapping into the unused heat generated by IT hardware, we can not only reduce energy waste but also unlock new revenue streams and contribute to a greener future. 

If you’re intrigued by the possibilities of heat reuse and want to explore how it can benefit your data center or application, we invite you to get in touch! Our team is passionate about maximizing the efficiency and sustainability of datacenters through cutting-edge solutions like immersion cooling and heat recovery systems. 

Bear in mind that we need to evaluate every heat reuse project separately in terms of: 

  1. The immersion cooling solution I.e., the number of units, water cooling loop conditions, tank setpoints, IT load capacity etc.  
  1. The heat recovery application I.e., capacity, type, integration, etc. 

Sounds good to you?