Why Liquid Cooling is the Future for Data Centers

Clarissa GarciaArticles, Blog

Liquid cooling

Air cooling has dominated the data center cooling industry, not only of its convenience but as previously installed air conditioning units only need a little expansion to provide cool air for the IT equipment. Liquid cooling on the other side has many disastrous concerns, especially when introduced in the market. These concerns include:

  • Price range
  • Complicated Maintenance
  • Liquid leaks and their effects on an electrical facility like a data center.
Forced air cooling is, still in use today. However, it has its own operating concerns:
  • Expensive maintenance
  • Huge power consumption
  • Component failure and malfunctions
  • Air pollutants
  • Humidity and condensation
  • Massive Carbon footprint
As the years pass by, liquid cooling has improved and provides advantages over air cooling. It is easier to maintain, scalable, and affordable. Plus, the elimination of air pollution concerns.
 
The benefits of liquid cooling are apparent in high-density facilities. These data centers need an efficient means of cooling for powerful and densely packed hardware. Moreover, the used energy from liquid cooling can be recycled to heat buildings. Thus, lessening the need for air conditioning and its carbon footprint.

Increasing Demands

Liquid cooling becomes more prominent as data centers increasingly aim to pack racks to full capacity. The higher the density of a rack, the higher the cooling demands. This demand may eventually exceed the capabilities of air cooling systems. Air cooling systems can’t allocate 20kW of cooling to high-density racks. While liquid cooling technology can provide up to 100kW per rack.
The dielectric liquid is an efficient heat absorber making it easier to pack more hardware components in smaller spaces. CPU and other server components can also operate at higher speeds because they are better cooled. Liquid cooling achieves greater thermal stability. And this improves the performance and reliability of the whole data center.

Retrofit Data Centers Into Liquid-Cooling

Most data center equipment is designed for air cooling and is not viable for liquid cooling. In this case, it’s best to install an air-to-liquid cooling distribution unit (CDU) as a first step before retrofitting the data center. This will allow for a liquid-cooled rack of servers utilizing direct-to-chip cold plates to be deployed without a dedicated liquid loop taken through the data center, and there is an added benefit of the liquid being controlled in smaller, more manageable volumes.
It’s a complex process to retrofit a data center into liquid cooling. However, data centers can always rely on The Green Grid, ASHRAE, and the Open Compute Project. They can assist from the compliance of construction materials to the actual implementation of the chosen liquid cooling method. Another option is the development of prefabricated modular data centers. This is where liquid cooling can be added to the facility without any reconstruction. many data centers can actually retrofit into liquid cooling right away. However, they still believe that they can be efficient with the best practices and optimal methods.

Environmental Impact and Energy-Efficiency

Liquid cooling environmental impact

Photo Credit: totaluptime.com/

Pressure for giant establishments to lessen their carbon footprints is increasing year by year. This pushes them to implement new technologies that are environmentally friendly and energy-efficient, sparking some brilliantly inventive initiatives around the use of liquid cooling. One excellent example is the use of liquid-cooled 5G network infrastructure within a housing estate where the waste energy is being for heating residential water. Thus, reducing the excess energy required for central heating within the houses.

The growing number of data centers using liquid cooling can bring the infrastructure to the next level. Because many businesses realize the benefits of liquid cooling now, it is possible that in the next three years it will double in growth. Data centers could also use this proposition to attract customers. As many customers now are looking for sustainable and energy-efficient partner companies.

The Limitations of Air-Cooling Technology

Not too long ago, owners and designers had the sense that cabinets approaching 20 to 30 kW load were approaching the natural limits of air-cooled devices. On the other hand, demonstration projects have shown cabinets upwards of 40 to 50 kW.
Processors, internal components, and other IT equipment usually have longer life as they are designed and built for warmer temperatures and higher delta T across devices. IT equipment typical delta t nowadays can reach up 40°C to 45°C whereas in the earlier days it can only reach up to 30°c. Not to mention that more airflow can be delivered with the use of some best cooling practices. These advances have pumped air cooling technology into a new life that was thought to be approaching an end.
But, that end may probably come in the near future. Keeping the data centers on track with the latest technologies while also making incremental advancements in air cooling, is the most cost-effective use of the current investment in the industry.
However, given the increasing demand for data, air cooling will eventually reach its limits. Device manufacturers, engineers, and designers will have to adjust their designs to accommodate liquid cooling.

Retrofit Data Centers Into Liquid Cooling

Most data center equipment is designed for air cooling and is not viable for liquid cooling. However, it will be better for the data center to completely convert into liquid cooling than to redesign its entire facility. In this case, it’s best to install an air to liquid Chilldyne Cooling Distribution Unit (CDU) as a first step before retrofitting the data center. This will allow for a liquid-cooled rack of servers utilizing direct to chip cold plates to be deployed without a dedicated liquid loop taken through the data center, and there is an added benefit of the liquid being controlled in smaller, more manageable volumes.

It’s a complex process to retrofit a data center into liquid cooling. However, data centers can always rely on The Green Grid, ASHRAE, and the Open Compute Project. They can assist from the compliance of construction materials to the actual implementation of the chosen liquid cooling method. Another option is the development of prefabricated modular data centers. This is where liquid cooling can be added to the facility without any reconstruction. many data centers can actually retrofit into liquid cooling right away. However, they still believe that they can be efficient with the best practices and optimal methods.

How Will The Transition Progress?

Photo Credit: https://www.gamingscan.com/liquid-vs-air-cpu-cooler

Of course, the transition from air cooling to liquid cooling would not happen overnight or a couple of days. There might be a transitional technology to help the industry into the inevitable change. This transition technology might just be in the form of hybrid coolers. Hybrid coolers can be more efficient than today’s air-cooled devices. However, data centers supporting hybrid coolers require at least two cooling plants. One is to cool the water that runs through the cold plates on the IT devices, and the other one is cooling the air-cooled loads in the building.

It’s expensive to provide for two plants and may have an impact on reaching return on investment. However, the best advances that can be made in the industry will occur when existing air-cooled data centers have reached their physical limit for cooling, and the only option for adding more capacity comes from refreshing the air-cooled IT in the data center to water-cooled IT equipment. Even if this change comes with the addition of plants to provide the cooling water to the new water-cooled equipment, the addition of this infrastructure is still more favorable than building new data centers from the ground up.

As those modifications become commonplace, the industry will see a clearer path to the purer, more leading-edge design of immersion cooling. That change will come in the next five years, it will dramatically change the industry, and we’ll check back again in ten years.

Liquid Cooling Monitoring

Liquid cooling temperature sensor

K-TYPE THERMA COUPLE SENSOR AND WIRELESS SENSOR

Monitoring and alarm are essential for any technology in the contemporary data center.  AKCP Monitoring Solutions includes a software suite that provides monitoring, alerts, including temperatures, flow, pressures, and leak detection, and importantly can report into data center management software suites.

 

Temperature Sensors

The temperatures of the server surface, liquid bath, and inlet and outlet coolant inside the coils were recorded and measured by a wireless temperature sensor or K-type thermocouple.

 

AKCP LIQUID COOLING SENSOR

AKCP Power Monitoring and Wireless Pipe Pressure Sensor

Power Monitoring Sensor

The power of the cooling unit was monitored using a power meter that can monitor and record real-time power consumption. The AKCP Power Monitor Sensor gives vital information and allows you to remotely monitor power eliminating the need for manual power audits as well as providing immediate alerts to potential problems. Power meter readings can also be used with the sensorProbe+ and AKCPro Server lives PUE calculations that analyze the efficiency of power usage in your data center. Data collected over time using the Power Monitor sensor can also be viewed using the built-in graphing tool.

Wireless Pipe Pressure Monitoring

The pressure in the tank was monitored by an automatic pressure relief valve with a pressure sensor. Digital pressure gauge for monitoring all kinds of liquids and gasses. Remote monitoring via the internet, alerts, and alarms when pressures are out of pre-defined parameters. Upgrade existing analog gauges. 

Wireless Valve Motor Control

Wireless, remote monitoring, and control of motorized ball valves in your water distribution network. Check status and remotely actuate the valves. Receive alerts when valves open and close, or automate the valve based on other sensor inputs, such as pressure gauges or flow meters.

Reference Links:

https://www.datacenterdynamics.com/en/opinions/20-years-of-liquid-cooling/

https://www.align.com/blog/is-liquid-cooling-technology-the-future-of-data-centers

http://green-data.blogspot.com/2016/08/data-center-design-raised-floor.html

https://www.acrjournal.uk/features/what-is-the-future-of-liquid-cooling/