Everything You Need to Know: Your Questions Answered


General Information

This section provides a foundational understanding of USystems, introducing the brand and its significance in the cooling solutions sector. It also explains key efficiency metrics such as Power Usage Effectiveness (PUE) and Water Usage Effectiveness (WUE), which are essential for evaluating data center performance
1. What is ColdLogik?

ColdLogik is a USystems brand, and denotes a range of cooling solutions including Rear Door Coolers and InRow Coolers

2. What is PUE (Power Usage Effectiveness)?

PUE is a metric used to determine the energy efficiency of a data center. The amount of power entering the data center is divided by the power used to run the active IT equipment

3. What is WUE (Water Usage Effectiveness)?

Water Usage Effectiveness is a sustainability metric used to determine the amount of water used by data centers to cool the IT equipment.


Product Specifications and Operations

Dive into the technical specifications and operational guidelines of USystems cooling solutions, including Rear Door Coolers and InRow Coolers. Learn about their frequency operations, weight, glycol-water ratio requirements, energy savings, water usage, airflow capacity, and compatibility with existing data center configurations. This section also addresses questions about achieving lower PUE, the highest kW duty achievable, and the use of refrigerants.
1. What frequency does the Rear Door Cooler ‘RDC’ and InRow Cooler operate?

Each Rear Door Cooler and InRow Cooler is fitted with a ColdLogik Management System ‘CMS’ and operates at 50Hz (Phase-Neutral) or 60Hz (Phase-Phase).

2. How heavy is a ColdLogik Rear Door Cooler?

Depending on the model and dimensions of the Rear Door Cooler, the dry weight will range from between 63.5kg (140lb) to 79.8kg (176lb). Filled weight between 76.2kg (168lb) to 91.2kg (201lb).

3. What percentage of glycol to water is required for a ColdLogik RDC design?

This will be dependent upon data centre location. Please contact our technical team via sales@usystems.com.com for further guidance.

4. What are the savings of a ColdLogik Rear Door Cooler ‘RDC’ data centre design, in comparison to a CRAC/H based system?

Up to 93% has been achieved over older CRAC/H based designs. This is possible because an RDC design data centre is far more energy efficient, using less power to achieve the same level of cooling; furthermore, an RDC design operates at higher supply water temperatures and can therefore utilise ambient free cooling.What is PUE (Power Usage Effectiveness)?

5. How can I achieve a lower PUE?

As cooling is the largest area of power consumption in a data centre, this is where the greatest improvements to PUE can be made. As data centre cooling specialists, the USystems ColdLogik product is designed to reduce PUE. This is accomplished by minimising the power draw requirements of the product through use of adaptive intelligence with the ColdLogik Management System. USystems also design solutions to use fluid at warmer temperatures, allowing the maximisation of free cooling potential, therefore dependence on mechanical cooling can be minimised or eliminated altogether. The PUE of the data centre is greatly improved over systems that rely on other technologies.

6. What is the lowest PUE USystems have achieved with a ColdLogik solution?

A PUE of 1.03 has been achieved as of 2020. Many ColdLogik systems are showcased in data centres that have gone on to receive notable recognition and awards centred around efficiency. Customer case studies can be found on our website at: https://usystems.com.com/case-studies/

7. How many litres of water does a ColdLogik deployment use?

A ColdLogik RDC design is a closed loop system, so when paired with similar mechanical cooling or other free cooling technologies such as borehole, river, sea water etc is totally sustainable. Which means each deployment only uses water at the initial set-up phase. The volume of water required at this stage will vary depending on the scale of the intended data centre deployment. The volume capacity of an individual ColdLogik cooler will range between 5.7L (1.5 US Gallons) to 15.4L (4 US gallons) in volume.

8. What external plant do I need to use to operate a ColdLogik System?

Depending on the operating parameters required (i.e. cooling duty, location, etc) ColdLogik can either operate independently of mechanical cooling, make use of local water sources such as lakes, boreholes, seawater, etc, or use traditional mechanical cooling technology such as chillers, cooling towers, dry air coolers, adiabatic coolers, etc.

9. Can I lift floor tiles when the ColdLogik Rear Door Cooler is in place?

Yes. Please contact our technical team via sales@usystems.com.com for further guidance.

10. What is the highest kW duty achieved by a ColdLogik Rear Door Cooler?

USystems recently launched CL23 HPC Rear Door Cooler is capable of 204kW (14°C / 57°F inlet water).For the medium density requirement, the CL20 is capable of 93kW (14°C / 57°F inlet water). However, using customer specified parameters while on-site, 106kW has been independently tested and verified on the 93kW rated cooler.Please email sales@usystems.com.com for further information.

11. What is the maximum airflow generated by the ColdLogik products (m3/h, cfm – cubic feet per minute)?

This would be dependent upon the chosen model. Please contact our technical team via sales@usystems.com.com for further information

12. Can I fit the Rear Door Cooler to any OEM rack?

Yes. This can be achieved with an Interface Frame. The Interface Frame provides a bridge between the ColdLogik Rear Door Cooler and any OEM rack. The interface frame is connected to the rack via a fixings kit and as standard fitted directly to the floor to transfer weight load.

13. How much depth does the Interface Frame add?

Please contact our technical team via sales@usystems.com.com for further information.

14. Can I use the ColdLogik Rear Door Cooler in legacy hot aisle and cold aisle configuration?

Yes. ColdLogik can be retrofit into Legacy installations.

15. Do USystems use refrigerants to produce a cooling effect?

No. Although refrigerant systems are widely utilised, they have their operational limits, complications, and environmental impacts, including but not limited to:Certified F Gas engineers are required to install or maintain products that use refrigerants. Water-cooled systems do not require this.The legislation around the use of refrigerants is ever-changing to conform to climate regulations which vary depending on location. Water-cooled systems are free of these restrictions.Refrigerant systems also operate under high pressures (up to 40 bar). Water-cooled systems typically operate at 3 bar.Refrigerant systems require the use of constant mechanical cooling to produce the cooling effect while the USystems ColdLogik Rear Door Coolers can operate with little or no mechanical cooling intervention.Refrigerants are becoming increasingly expensive to purchase due to demand and restrictions.

16. What is the difference between static and dynamic load?

The static load refers to how much weight a rack can hold when sited and the dynamic load is how much weight a rack can hold when being moved on its castors.

17. Do I have to put a Rear Door Cooler on every rack?

The static load refers to how much weight a rack can hold when sited and the dynamic load is how much weight a rack can hold when being moved on its castors.


Management and Control Systems

Explore how the ColdLogik Management System (CMS) controls and optimizes the performance of Rear Door Coolers. This section details the adaptive intelligence of the CMS, how it reads and reacts to temperature changes, and the overall impact on room environment and cooling efficiency.
1. What controls the ColdLogik Rear Door Coolers and how does it work?

The RDC’s are controlled by the ColdLogik Management System (CMS). The CMS adaptive intelligence is designed to control the whole room environment.The CMS continuously reads temperature from three zones, before the coil, after the coil, and an external room temperature sensor. The CMS uses the temperature information to control the volume of fluid provided by the valve, and the overall speed of the fans in the cooler. Should the equipment inside the rack on occasion produce more heat, the CMS will react, and increase fan speed / fluid volume to achieve the air off temperature required. In the event of additional temperature changes required, the CMS can demand a change in supply water temperature from mechanical cooling.

Knowledge Hub

USystems Hub: Articles, Case Studies & Insights

Explore the latest breakthroughs and expert analyses with USystems' curated collection of articles, case studies, and insights


Data Center Solutions
that Exceed Expectations

Get in touch with us at USystems Ltd to join the journey towards more efficient and sustainable data centers. Our leading and innovative technologies are designed to help you use less energy and reduce your carbon footprint on a global scale. Contact us now to explore how we can work together for a greener future.
Slider with Navigation Buttons