1 · Physical & Service Access
- Enclosure: 1100 W × 1200 D × 2200 H mm
- Maintenance: front 1200 mm; each side 650 mm; rear 150 mm
- Top connections: FWS / TCS 4 in Tri-clamp; fill port 1 in Tri-clamp
Liquid Cooling
Liquid Cooling, From CDU to Facility Loop
The complete thermal chain for high-density AI computing: CDU architecture, coolant chemistry, loop topology, plumbing and the facility systems that reject the heat.
Core Architecture
Water Cooling CDU, Layer by Layer
Five functional layers make up the coolant distribution unit. Step through each one.
Layer 1 of 5
Exterior Frame
Front access door and rigid structural frame.
The outer enclosure protects every internal layer while keeping the front fully serviceable. Filtered intake panels and a rigid welded frame carry the full wet weight of the unit.
Layer 2 of 5
Control Hub
Smart control panel for real-time telemetry.
A dedicated controls column carries the HMI, PLC and sensor wiring: real-time flow, temperature and pressure telemetry with alarm thresholds reported upstream to BMS.
Layer 3 of 5
Circulation Core
High-efficiency pump module and expansion tank for pressure balancing.
Redundant pumps and an expansion tank keep the secondary loop moving at stable pressure. Pump modules are side-removable for service without draining the loop.
Layer 4 of 5
Thermal Transfer
High-performance plate heat exchanger.
The plate heat exchanger is the boundary between facility water and the IT coolant loop: two hydraulic worlds exchange heat without ever mixing.
Layer 5 of 5
Distribution
Flow-optimized manifold, particle filter, and precision flow / temperature sensors.
The manifold layer distributes conditioned coolant to rack supply lines: flow-optimized headers, dual particle filters and precision instrumentation on every branch.
High Efficiency
Optimized hydraulics.
Modular Design
Rapid customization.
Smart Monitoring
Active risk mitigation.
Liquid Cooling Infrastructure
CDU Supports Serviceable Hydraulics up to 10 bar
Top-entry sanitary interfaces, 4 °C approach heat exchange and high-availability protections for high-density liquid cooling.
0°CHeat Exchanger ATDOversized plate heat exchanger
50/55psiPump DutyHigh-head VFD pump, side-removable
0barWorking PressureFWS and TCS maximum, 145 psi
18–50°COperating LimitInstallation altitude up to 3000 m
2 · Cooling & Hydraulic System
- Oversized plate heat exchanger: 4 °C ATD
- High-head VFD pump: 50 psi rated / 55 psi nominal; side-removable
- TCS: dual 25 µm filters | FWS: two-way control valve
- Integrated automatic glycol feeder
3 · Operating Envelope & Reliability
- Ambient 18–50 °C; altitude up to 3000 m
- FWS: water or ≤40% ethylene glycol | TCS: PG25 (25% propylene glycol)
- Dual power with electromechanical switch; rope-type leak detection
Cooling Comparison
Air vs. Liquid Cooling
Scenario A: Air Cooling
- Traditional server rack in hot-aisle / cold-plenum layout
- Fans on every server push heat into the room
- Chiller and CRAH units work at high energy to remove it
- Energy hogs: fans and chiller
PUE ~1.50
(IT + air cooling + other) / IT power
Scenario B: Liquid Cooling
- Advanced high-density rack with custom cold plates on every CPU / GPU
- Cool dielectric fluid carries heat straight off the silicon
- CDU and heat exchanger reject it through the facility water loop
- Energy efficient: highly efficient pumps
PUE ~1.18
(IT + liquid cooling + other) / IT power
Energy Efficiency
Efficiency & Benefits Comparison (PUE)
Lower PUE indicates higher energy efficiency. Liquid cooling demonstrates significant savings.
1.50
1.00
0.50
0
Scenario A: Air Cooling
0
Scenario B: Liquid Cooling
Higher Power Density
Allows for more compute in a smaller footprint.
Reduced OpEx
Significantly lower energy costs and maintenance.
Improved Sustainability
Lower carbon footprint through greater efficiency.
Enhanced Reliability
Stable temperatures for critical hardware.
Liquid-Cooling Topology
Three Interfaces Control Liquid-Cooling Risk
Freeze hydraulics, cleanliness, isolation controls and acceptance evidence at the primary, CDU and rack-side interfaces. Reference basis: 1.6 MW facility / 700 kW IT.
01 · Primary Plant
- Supply / return / flow / ΔP (pressure differential) frozen at the boundary
- Flowmeter calibration plus sizing calculation
02 · CDU Boundary
- Design requirement: N+1
- Primary / secondary ports with flexible joints
- Outlet temperature, status and BMS interlink; power, ground and ownership defined
03 · Secondary / Rack Side
- CDU outlet to rack interlock ball valve
- 304+ hygienic pipe; prefabricated argon weld
- Flush, clean and cap before shipment; ring test, isolation and leak collection
| Risk Control | Primary Plant | CDU Boundary | Secondary / Rack Side |
|---|---|---|---|
| Hydraulics | Supply/return, design flow, available ΔP | Primary/secondary ports, capacity, control range | Ring loss, branch balance, rack envelope |
| Cleanliness | Water treatment, makeup ownership | Protect heat exchanger and sensor ports at install | 304+ hygienic pipe; argon weld, flush, cap |
| Leak / Service | Independent supports, flexible joints, isolation | Accessible isolation, traceable replacement | Interlock valve, leak detect, pan slope 0.5% / depth 100 mm |
| Controls / Proof | Flow, temperature, valve state, alarm point list | Outlet T, status, interlink, power, ground to BMS | FAT/SAT: isolation, leak and restoration |
Acceptance evidence: flowmeter calibration and calculation, pressure report per section, flush/clean/cap record, site pressure and flush report, BMS point and alarm check, isolation, drain and recovery.
Distribution Manifold & Plumbing
Engineered for Efficiency, Reliability and Precision
The in-rack fluid network: coolant pathways, regulation, connections and protection in next-generation data centers.
Fluid Pathway Core
- Liquid coolant: PG25
- Spec: 99.9% purity
Regulation
- Solenoid valves; blind mate (NSEC)
- Sensors: level / pressure / flow
- Flow: 500 LPM
Connections
- EPDM hoses; quick coupling (UQD / UQDB)
- Flexible metal bellows
- ID: 12 mm
Protection
- Leakage detection; O-rings; clamps
- Leakage threshold: 0.1 ml
High Efficiency
Optimized coolant distribution for maximum thermal performance.
Reliability
Precision components ensure stable operation and long-term durability.
Safety
Leakage protection and real-time monitoring for mission-critical systems.
Scalability
Modular design for easy integration and capacity expansion.
Secondary Coolant
PG25 Secondary-Side Coolant (JEFFCOOL® ISF-25)
Heat-transfer fluid designed for high-density liquid-cooled servers and copper cold plates. Intel-recommended reference fluid.
Low Toxicity & Environmental Profile
Propylene-glycol (PG) based for high safety and lower environmental impact.
Long-Life Corrosion Protection
Proprietary corrosion inhibitors protect copper, brass, stainless steel and titanium.
Intrinsic Biostatic Performance
At 25% concentration, bacterial growth remains under 100 CFU/ml; no supplemental biocides are required.
Stable, Low-Maintenance Operation
Reduces piping-fouling risk associated with microbial growth and lowers routine maintenance frequency.
| Technical Specifications · JEFFCOOL® ISF-25 | |
|---|---|
| pH | 8.0–10.5 |
| Freezing Protection | -10 °C |
| Thermal Conductivity @ 50 °C | 0.475–0.525 W/mK |
| Specific Heat @ 50 °C | > 3.5 kJ/kg-K |
| Viscosity @ 50 °C | 1.06 cP |
| Sulfate | <10 ppm |
| Chloride | <5 ppm |
| Total Hardness (as CaCO3) | <20 ppm |
Facility Water Quality Requirements & Control Plan
Primary Loop: Water Quality & Reliability
Fully sealed circulation with low makeup demand, designed to protect copper and keep plate heat exchangers clean. The closed loop transfers heat through the plate heat exchanger, and limits follow ASHRAE and equipment water-quality requirements.
| Parameter | Control Limit | Engineering Purpose |
|---|---|---|
| pH | 8.0–8.8 | Protects copper from corrosion |
| Conductivity | ≤ 800 µS/cm | Reduces electrochemical corrosion |
| Total Hardness (CaCO3) | ≤ 50 ppm | Prevents heat-exchanger scaling |
| Chloride (Cl-) | ≤ 50 ppm | Prevents copper pitting |
| Dissolved Oxygen | ≤ 0.5 ppm | Critical corrosion-control parameter |
Release rule: all five limits must pass; any failure blocks system filling. Any source, same acceptance criteria.
Pre-Fill Water Analysis
pH, hardness, conductivity, chloride and dissolved oxygen.
Dedicated Chemical Treatment
Conditioning controls scale and corrosion.
100% Compliance Release
Fill only after all five limits pass.
Closed-Loop Operating Control
Keep sealed; revalidate each makeup batch.
Dry Cooler System
1 MW Containerized Dry Cooler: Cooling & Control
A 40 ft module packages EC fans, V-shaped coils, liquid interfaces and controls for high-density AI data centers.
0kWRated Cooling CapacityCoolant inlet 45 °C / outlet 35 °C; ambient air 27 °C
0fansEC Axial Fans · 19 kW Total3-phase 380–480 VAC, 50/60 Hz
0LPMLiquid-Side FlowMax 1 MPa; drop 40 kPa; DN150 × 2
0kg40 ft Module, DryApprox. 12.20 × 2.45 × 2.90 m, lifting and service access integrated
Chiller System
1 MW Containerized Chiller: Compression & Controls
A 40 ft module packages inverter scroll compressors, EC fans, liquid interfaces and multi-protection for high-density AI data centers.
0kWRated Cooling CapacityCoolant inlet 25 °C / outlet 20 °C; ambient air 30 °C
8+8Inverter Scroll Compressors + EC FansCompressors 22.5 kW × 8; fans 3.5 kW × 8; 380–480 VAC
0LPMLiquid-Side FlowR454B refrigerant; max 1 MPa; DN150 in / out
0kg40 ft Module, DryApprox. 12.20 × 2.45 × 2.90 m; ambient -25 to 43 °C, RH 8–85%
Reference Case
Data Center Cooling Systems Reference Case
A complete heat-rejection chain from DLC rack to cooling tower. Red lines carry hot return water, blue lines carry cold supply.
Cooling tower · 500 RT 1+1Final heat rejection to ambient (1,590 kW); 32 °C water returns to the plate heat exchangers.
Plate heat exchangersIsolate the sealed primary loop from tower water and from the IT coolant loop while transferring the full thermal load.
Helical rotary chiller · 120 RT 1+1Trims supply water for the CRAH air loop (375 kW); chiller inlet water 32 °C.
CRAH · 375 kWHandles the residual air-side load; indoor 37 °C, cooled aisle 25 °C.
CDU + DLC rackGPU direct liquid cooling; CDU inlet water 32 °C, return 40 °C. IT workload 1,522 kW with 357 kW air-side dissipation.
Pump group + FVDCirculates primary water with verified flow direction at every branch, behind a check valve.
0kWIT Workload357 kW air-side heat dissipation
32/40°CGPU DLC CDUInlet water 32 °C, return 40 °C
0RTCooling Tower1+1 design, 1,590 kW
37/25°CRoom / Cooled AisleIndoor 37 °C; cooled aisle 25 °C
Ready to Freeze Your Thermal Design?
From CDU selection to facility water chemistry, our engineers close every interface on the list.