Technology Q&A

Direct Contact Liquid Cooling (DCLC)

What is Direct Contact Liquid Cooling (DCLC)?
DCLC is a technology developed and patented by CoolIT Systems that uses warm liquid rather than cold air to dissipate heat from computer and server components. By capturing component heat in a liquid path, DCLC allows for higher component performance and reliability, higher densities and decreased data center operating expenses through a decrease or elimination of chillers and CRACs.

Why does CoolIT recommend liquid cooling instead of traditional air cooling?
By integrating DCLC, dependence on expensive air conditioning and air handling systems is dramatically reduced, enabling more servers per rack, low power usage and access to significantly higher performance potential. Rack DCLC integration translates into an effective and scalable cooling strategy which significantly reduces OPEX.

What is a Closed-Loop DCLC System?
Closed-Loop DCLC Solutions are cooling systems designed by CoolIT that exist entirely within the Desktop or Server. The sealed liquid loop ships are charged with coolant, and installation is comparable to that of a standard heat sink. CoolIT has many types of Closed-Loop systems for desktops and servers (1U, 2U, and custom rack-mount).

What is CoolIT Systems Rack DCLC?
CoolIT's Rack DCLC platform is a modular, rack-based, advanced cooling solution that allows for dramatic increases in rack densities, component performance and power efficiencies. Rack DCLC is compatible with new and existing data centers and can work whether facility water is available or not.

What does Rack DCLC do for high performance computing (HPC)?
At the rack and server level, Rack DCLC solutions allow for a major increases in density while also allowing processors to run cleaner at lower temperatures and utilizing fewer in-server fans. At the facilities infrastructure level, Rack DCLC allows for an 80% or greater reduction in air cooling infrastructure using ASHRAE W3-W5 water to cool the processor load.

What is the acceptable facility water temperature for Rack DCLC?
The acceptable liquid temperatures are ASHRAE W2 to W5 (W4= 2°C-45°C , W5> 45°C).

What servers and racks are compatible with Cool IT Rack DCLC?
CoolIT Rack DCLC supports any server and rack model. Our low profile R3 server modules are ideal for high density servers and easily accommodate any existing products.



What are the three modules that make a Rack DCLC solution?
They are: Heat Exchanger Module (CHx or AHx), Manifold Modules and Server Modules.

What are the CHx and AHx modules?
CHx Module: Liquid-to-Liquid heat exchangers which use facility water to capture and remove component heat from the compute environment

  •  CHx650: 650kW of processor load with ASHRAE W4 or W5 water (manages network of 5 to 20 racks)
  •  CHx80: 80kW of processor load with ASHRAE W3-W5 water (manages a single rack)
  •  CHx40:  40kW of processor load with ASHRAE W4 or W5 water (manages a single rack)

AHx Module: The Liquid-to-Air heat exchanger platform requires no facility water to operate, sits on top of the rack for which multiple designs available such as: hot aisle, cold aisle, chimney, etc.

  • AHx20: Manages 20kW of processor load

Service & Maintenance

Can users monitor and manage their Rack DCLC systems?
Yes, all Rack DCLC solutions ship with a management system that can be accessed remotely (SNMP and web server) and at the rack level.

Is it possible to disconnect any of the system modules in case of an emergency?
Yes, servers are hot-swappable with the Rack DCLC system. Dry-break quick disconnects allow removal of any part of the system (Heat exchanger, Manifolds or Server modules) as needed without disrupting the cooling functionality of the remaining servers. This feature is particularly useful in case of an emergency or if users need to isolate any one area.

Does CoolIT provide partners and customers with support services and warranty?
Yes, CoolIT does provide support services and warranty to its partners and customers as required.

Does CoolIT have any ISO Certification?
Yes, CoolIT has ISO 9001: 2008.


Is liquid cooling going to increase my server costs?
The initial cost of integrating liquid cooling is quickly offset by several factors:

  • A high density solution requires less standard data center equipment (racks, switches, raised-floor, etc.), which lowers overall capital expenses
  • Rack DCLC enables a 25-30% decrease in operating expenses, thanks to reduced chilled water requirements
  • The average ROI for Rack DCLC solutions is 0-6 months

What is the difference bewteen Direct Contact Liquid Cooling and immersion cooling? 

CoolIT Systems Rack DCLC™

Single Phase Immersion Cooling

$.5 - $.75 per watt (can go as low as $.35) $1.05 per watt (*data from company website)
Allows for servers to be unplugged and maintained as per normal service protocols Servers must drip-dry and be cleaned prior to service
Uses only the highest quality components and materials, stringent manufacturing methods and extensive testing to ensure a long lifecycle Rubbers and plastic slowly leach into mineral oil which changes the heat transfer properties and reduces the lifecycle of components 
Easily integrates into any data center environment using standard rack and server architecture Expensive to retrofit, requiring the replacement of all HDD with SSD (or adjustments to HDDD) and non-standard equipment, as existing racks must be discarded
Increases density with fully populated vertical racks which make the most of available square footage Mineral oil tubs do not maximize the use of space for traditional data rooms, resulting in far less density per square foot
Leverages a global supply chain with over 2 million cooling nodes shipped Immersion is new and experimental technology that has not been produced at scale
Enables easy mixing of liquid air cooled racks in a single room (HPC mixed with general use space) Eliminates possibility for mixed-use space




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