Sourcing Liquid-Cooled Colocation Capacity
Data Centre Axis assists buyers seeking high-density colocation capacity. We review stated requirements against independent research across our public UK and Australian directories, reviewing enquiries elsewhere individually. Where requirements align, we prepare individually scoped capacity briefs and arrange managed private introductions between buyers and operators.
Specialist advisory is scoped individually under separate agreements. Detailed technical, commercial, or structural evaluations require a separate agreed scope. Commercial terms and engineering decisions remain strictly between transacting parties. The sections below provide diligence questions for technical specialists.
Buyers preparing an enquiry should specify:
- Target metropolitan market and country.
- Total power requirement and planned rack densities.
- Hardware delivery milestones and deployment phases.
- Preferred cooling architecture, such as direct-to-chip cold plates or immersion tanks.
Mechanical Plant Boundaries and Fluid Loops
Assessing a colocation facility begins by separating central mechanical plant from white-space cooling circuits. Liquid cooling separates primary facility water from secondary technology cooling circuits using heat exchangers.
According to the OCP Data Center Facilities project, the Coolant Distribution Unit (CDU) serves as “the interface between facility-water systems and Technology Cooling Systems (TCS) serving cold plates, door heat exchangers, and immersion-cooled IT”. The primary facility water loop circulates water from chillers or dry coolers to the CDU, while the secondary loop circulates treated fluid to server hardware.
Research from IEA 4E EDNA notes that direct-to-chip single-phase liquid cooling “is the most mature and widely deployed currently, commanding approximately 43% of the liquid cooling market by revenue. Immersion cooling is though the fastest-growing segment”.
Key diligence questions for operators:
- Does the primary water loop supply liquid-cooled rows exclusively, or share pipework with air handlers?
- Can technicians isolate a single row header without interrupting flow to adjacent racks?
- What pipework materials are installed, and do they match CDU heat exchanger metallurgy?
Heat Capture and Air Handling
Adopting liquid cooling does not remove the need for data hall air handling. Direct-to-chip cold plates extract heat from high-wattage processors, but adjacent electronics reject heat directly into ambient room air.
Technical documentation from the Open Compute Project establishes that “A typical cold plate cooling system may capture 70%-80% of the ITE heat… TCS capacity requirements for immersion would be closer to 100%”. In cold plate setups, the remaining heat dissipates into the room from memory modules, voltage regulators, and network transceivers. If airflow fails, ancillary components risk thermal throttling.
Key diligence questions for operators:
- Are room air handlers sized to remove twenty to thirty percent of total rack power as sensible heat?
- What containment structures are installed, and do partition seals withstand elevated static pressure?
- Do air circulation fans stay powered by uninterruptible power systems during utility transfers?
Operating Temperatures and Water Supply
Operating temperatures dictate chiller dependency and efficiency. Buyers must verify whether the facility water loop maintains contracted supply temperatures during summer conditions without derating performance.
Guidelines from the Open Compute Project confirm that water-based TCS loops “typically operate <49 °C (120 °F) and are not expected to be >66 °C (150 °F)”, with temperatures above 66 °C requiring a wetted-materials review to prevent polymer degradation. Technical documentation from Dell Technologies recommends a 20 °C supply for rear-door heat exchangers and 32 °C for CDUs, site-dependent.
Immersion architectures require different physical tolerances. The Open Compute Project immersion requirements mandate that solutions handle facility water supply partial vacuum to 50 kPa absolute and pressure to 1000 kPa gauge, whilst supporting glycol mixtures to 50%.
Key diligence questions for operators:
- What was the peak primary water supply temperature recorded over the past three summers?
- Does the facility use dry coolers, cooling towers, or mechanical chillers during heatwaves?
- How does the operator prevent condensation if primary supply water temperatures fall below room dew point?
Distribution Units and Demarcation Lines
The physical boundary between tenant equipment and facility plant sits at the Coolant Distribution Unit or the row manifold. Determining who owns, operates, and services the CDU is essential to avoid operational conflicts. Technical specifications from Dell Technologies indicate that customers “are responsible for validating the selected CDU, secondary fluid network, and facility infrastructure”, with maintenance schedules set by the CDU vendor.
Operators deploy CDUs as centralised perimeter units distributing fluid through shared floor headers, or as dedicated in-row or in-rack units that isolate chemistry and pressure control while consuming white-space floor area.
The Chilldyne CDU-1500 specification, published by Tecomas, describes “negative pressure technology” designed to draw fluid through cold plates under sub-atmospheric pressure to mitigate leak risks.
Key diligence questions for operators:
- Does the operator or the tenant provide, service, and warrant the CDU?
- What pump redundancy is installed within the CDU, and can failed pumps be swapped online?
- Are secondary manifold connections equipped with dry-break quick-disconnect couplings?
- Where does contractual liability fall if a leak in facility pipework damages tenant hardware?
Coolant Chemistry and Water Treatment
Secondary fluid quality directly impacts processor life and cooling efficiency. Inadequate water treatment causes biological fouling, galvanic corrosion, and micro-channel blockages inside cold plates.
Maintenance procedures from Dell Technologies state that coolant chemistry testing is required “a minimum of one test every 6 months… on each Secondary Fluid Network”. Regular testing verifies that inhibitor packages and fluid properties remain within manufacturer limits.
Key diligence questions for operators:
- Who collects fluid samples, and which accredited laboratory conducts chemical testing?
- What corrosion inhibitors, biocides, and glycol ratios does the operator require or permit?
- What micron rating is specified for inline filters, and are dual-filter bypass arrangements installed for online swaps?
Structural Loads and Pipework Routing
Liquid cooling adds substantial weight from fluid manifolds, cold plates, and dense server components. Buyers must verify whether slab and raised-floor load ratings match the planned equipment. Pipe routing also requires mechanical segregation from electrical infrastructure.
Key diligence questions for operators:
- What are the point-load and distributed load ratings for the concrete slab or raised floor?
- Can the delivery path from loading bays to the white space support rolling weights of heavy rack cabinets?
- How does the operator physically segregate coolant pipework from electrical busways and power cables?
- What containment bunding, drainage sumps, and moisture-sensing ropes protect the white space beneath CDUs?
Electrical Power and Pumping Resilience
Liquid cooling systems rely on continuous electrical power to circulate fluid. If circulation pumps stop, server silicon temperatures rise quickly, triggering emergency shutdowns. Buyers must examine how mechanical pumping loops integrate with facility power paths.
Key diligence questions for operators:
- Are CDU pumps dual-corded and connected to separate uninterruptible power supply circuits?
- Do secondary circulation pumps maintain continuous flow during the mechanical transition to emergency backup generators?
- What automated controls isolate valves or shut down compute nodes if a sudden pressure loss signals a major fluid breach?
Commercial Terms and Service Levels
Colocation contracts for liquid cooling must move beyond standard room temperature and power availability metrics. Buyers and operators must establish measurable thermodynamic and hydraulic commitments.
Key diligence questions for operators:
- What specific fluid flow rate, supply temperature, and differential pressure commitments are written into the service level agreement?
- What are the agreed remedy periods and compensation terms if supply water temperatures exceed contracted ceilings during peak weather?
- Where does contractual liability fall if a leak in facility-managed pipework damages tenant server hardware?
Capacity Briefs and Introductions
Public research directories cover Australian data centres and UK data centres. Requirements in other geographic markets are reviewed individually upon request. For reviews of development sites, refer to data centre land. For broader transaction context, consult our colocation advisory capabilities or general colocation research.
Facility operators with liquid cooling capacity can submit property details through our asset submission portal. To submit a requirement, complete a capacity sourcing enquiry. Commercial negotiations, engineering design, and legal agreements remain strictly between the transacting parties.