Do these 3 things before closing this tab:
1Scan for outdated or missing drivers - takes under a minute2Clear out junk files and repair common Windows errors3Fix the driver behind crashes, sound loss and screen glitchesSome links on this page are affiliate links: if you buy through them we may earn a commission, at no extra cost to you.
CoolIT announced three coolant distribution units on July 9, 2024: the AHx180 and AHx240, which reject heat to air, and the CHx500, which transfers heat to facility water. Their advertised capacities are 180 kW, 240 kW, and 500 kW respectively, but those figures describe different configurations and conditions—not interchangeable measures of server-rack support. The central choice is whether a site needs liquid cooling without a facility-water loop or can use one to handle a much larger aggregate heat load.
This is a historical launch briefing, not a report of a new 2026 announcement. CoolIT said the units were in production and shipping from its Canadian facility at launch; that statement is not a current lead-time guarantee. CoolIT’s launch announcement was published July 9, with ServeTheHome’s report following on July 14.
At a glance
| Model | Heat-rejection type | Advertised capacity | Facility-water loop | Launch rack-support claim |
|---|---|---|---|---|
| AHx180 | Liquid-to-air | 180 kW at 15°C approach | No | Up to 2 GB200 NVL72 racks |
| AHx240 | Liquid-to-air | 240 kW at 15°C approach | No | Up to 4 GB200 NVL72 racks |
| CHx500 | Liquid-to-liquid | 500 kW at 5.5°C approach | Yes | Four units combined: up to 2 MW, subject to system design |
Capacity and rack counts above are CoolIT’s stated figures, not independent test results. Rack support depends on the server and cold-plate design, coolant temperatures and flow, pressure drop, how much heat reaches the liquid loop, redundancy choices, and workload. The CHx500’s 2 MW figure is for four units together, not one CDU.
What a CDU does—and what it does not
A coolant distribution unit circulates coolant through a technology loop serving server cold plates and manifolds, and helps regulate flow, pressure, and temperature. It moves heat out of that loop through a heat exchanger. In a liquid-to-air design, fans and a heat exchanger transfer the heat to the data-center air. In a liquid-to-liquid design, a heat exchanger transfers it to a separate facility-water loop.
#1 Best Overall
- CONTACT FRAME FOR INTEL LGA1851 | LGA1700: Optimized contact pressure distribution for longer CPU life and better heat dissipation
- ARCTIC's P12 PRO FAN: More power at any speed - more powerful and quieter than the P12, especially at low speeds. Higher maximum speed for optimal cooling performance under high load
- NATIVE OFFSET MOUNTING FOR INTEL AND AMD: Shifting the cold plate center towards the CPU hotspot ensures more efficient heat transfer
- INTEGRATED VRM FAN: PWM-controlled fan that lowers the temperature of the voltage converters and thus ensures reliable performance
- INTEGRATED CABLE MANAGEMENT: The PWM cables of the radiator fans are integrated in the sheathing of the hoses so that only a single visible cable is connected to the motherboard
A CDU is not the cold plate, rack manifold, cooling tower, dry cooler, chiller, or the entire facility cooling plant. Those components may be needed elsewhere in the system. That distinction matters particularly for the AHx units: “no facility water required” means they do not need a facility-water loop for heat rejection; it does not mean they cool a room independently of the building’s air-handling and heat-removal systems.
AHx180 and AHx240: liquid cooling without facility water
Both AHx models are designed for sites that want direct liquid cooling but do not have a suitable facility-water loop. They circulate coolant to the liquid-cooled hardware and reject its heat to the data-center air. That may simplify a retrofit or avoid adding water distribution, but the heat still has to be carried away by room airflow and the facility’s cooling infrastructure.
AHx180
The AHx180 is rated at 180 kW at a 15°C approach temperature difference. Launch specifications described two pumps, four fans, a two-rack footprint, and pump redundancy. CoolIT’s current product page lists 11.32 kW power consumption and says the unit can support up to two GB200 NVL72 racks. Those are vendor specifications and system-support claims, not a guarantee for every configuration. See the AHx180 product page.
Recommended Free Tools
Rank #2
- CONTACT FRAME FOR INTEL LGA1851 | LGA1700: Optimized contact pressure distribution for longer CPU life and better heat dissipation
- ARCTIC's P12 PRO FAN: More power at any speed - more powerful and quieter than the P12, especially at low speeds. Higher maximum speed for optimal cooling performance under high load
- NATIVE OFFSET MOUNTING FOR INTEL AND AMD: Shifting the cold plate center towards the CPU hotspot ensures more efficient heat transfer
- INTEGRATED VRM FAN: PWM-controlled fan that lowers the temperature of the voltage converters and thus ensures reliable performance
- INTEGRATED CABLE MANAGEMENT: The PWM cables of the radiator fans are integrated in the sheathing of the hoses so that only a single visible cable is connected to the motherboard
AHx240
The AHx240 raises the advertised capacity to 240 kW at a 15°C approach. Launch materials described two pumps, eight fans, and a two-rack footprint. CoolIT’s current product page lists 15.5 kW power consumption. Its rack-support references have evolved: the 2024 launch claim was up to four GB200 NVL72 racks, while current CoolIT pages describe different GB200 and GB300 configurations. Treat the rack count as configuration-specific, not as a timeless property of the CDU. The current AHx240 page provides current vendor information; the AHx2 technical page gives additional operating details.
The AHx240 is not automatically the better choice. Its higher capacity may mean more thermal headroom or fewer units for a given deployment, but it also has greater listed electrical consumption. Either model needs suitable power, airflow, floor space, piping, access for maintenance, and enough room-level heat-rejection capacity. Choose based on actual rack loads, the intended operating envelope, redundancy policy, and the facility—not the kW headline alone.
CHx500: higher density with a facility-water loop
The CHx500 is a liquid-to-liquid CDU rated at 500 kW at a 5.5°C approach. Rather than sending the heat into room air through a bank of CDU fans, it transfers heat from the technology loop to facility liquid. This architecture is intended for higher aggregate loads and requires the site to provide a compatible water or other heat-rejection loop.
Rank #3
- Simple, High-Performance All-in-One CPU Cooling: Renowned CORSAIR engineering delivers strong, low-noise cooling that helps your CPU reach its full potential
- Efficient, Low-Noise Pump: Keeps your coolant circulating at a high flow rate while generating a whisper-quiet 20 dBA
- Convex Cold Plate with Pre-Applied Thermal Paste: The slightly convex shape ensures maximum contact with your CPU’s integrated heat spreader, with thermal paste applied in an optimised pattern to speed up installation
- RS120 ARGB Fans: RS ARGB fans create strong airflow and high static pressure, with easy ARGB control via a compatible motherboard. CORSAIR AirGuide technology and Magnetic Dome bearings ensure great cooling performance and low noise
- Easy Daisy-Chained Connections: Reduce the wiring in your system by daisy-chaining your RS ARGB fans and connecting them to just one 4-pin PWM fan header and one +5V ARGB header
CoolIT said four CHx500 units can be installed in one 48U rack with a 3U coolant reservoir, for a combined claimed capacity of 2 MW. Launch specifications described three pumps with N+1 redundancy and A+B redundant hot-swappable power supplies. CoolIT also cited ASHRAE W45 warm-water support. Warm-water operation can suit free-cooling or heat-reuse strategies, but it does not guarantee either: results depend on facility-water temperatures, climate, heat exchangers, controls, and the downstream plant.
The Tool Desk
Outbyte Driver Updater FREEFix the driver behind crashes, sound loss and screen glitchesFind Drivers →Outbyte PC Repair FREEClear out junk files and repair common Windows errorsFree Scan →CoolIT’s launch example said a four-unit stack could serve up to 58 racks of 21 direct-liquid-cooled 2U servers per rack at 14.7 kW per rack—1,218 servers in all. That is a vendor deployment example based on stated assumptions, not a universal design rating. StorageReview’s contemporaneous coverage includes the example and additional specifications.
How to interpret the capacity numbers
Approach temperature difference (ATD) is the temperature difference across the heat exchanger between the coolant and the heat-rejection medium. Capacity depends on operating conditions, so a 500 kW rating at a 5.5°C approach should not be compared casually with 180 kW or 240 kW at a 15°C approach as though the figures came from one identical test. Ask for guaranteed capacity at the temperatures and flow conditions planned for the site.
Rank #4
- CONTACT FRAME FOR INTEL LGA1851 | LGA1700: Optimized contact pressure distribution for longer CPU life and better heat dissipation
- ARCTIC's P12 PRO FAN: More power at any speed - more powerful and quieter than the P12, especially at low speeds. Higher maximum speed for optimal cooling performance under high load
- NATIVE OFFSET MOUNTING FOR INTEL AND AMD: Shifting the cold plate center towards the CPU hotspot ensures more efficient heat transfer
- INTEGRATED VRM FAN: PWM-controlled fan that lowers the temperature of the voltage converters and thus ensures reliable performance
- INTEGRATED CABLE MANAGEMENT: The PWM cables of the radiator fans are integrated in the sheathing of the hoses so that only a single visible cable is connected to the motherboard
Flow and pressure matter too. LPM/kW means coolant flow in litres per minute per kilowatt of heat load. The AHx240 page publishes flow information at specified pressure conditions; different pressure-drop assumptions can yield different flow figures. Neither the CDU rating nor a rack-count claim alone tells an operator whether a particular cold-plate and manifold assembly will receive enough coolant at the needed pressure.
Also account for the fraction of server heat captured by liquid cooling, peak and transient workloads, supply and return temperatures, and the required redundancy configuration. The launch claims that the AHx units can support two or four GB200 NVL72 racks describe CoolIT’s optimized system claims. They should not be generalized to arbitrary racks or treated as independent validation.
Deployment trade-offs
| Consideration | Liquid-to-air AHx | Liquid-to-liquid CHx500 |
|---|---|---|
| Facility water | Not required for CDU heat rejection | Required for heat transfer to the facility loop |
| Heat destination | Data-center air, then the building’s cooling system | Facility liquid loop, then its heat-rejection plant or reuse system |
| Likely fit | Retrofits or sites without water distribution | High-density facilities with suitable liquid infrastructure |
| Key facility checks | Airflow, containment, HVAC headroom, electrical service | Water temperature, flow, pressure, chemistry, filtration, isolation, and plant capacity |
The AHx approach can avoid immediate investment in facility-water distribution and may fit existing air-cooled layouts. Its trade-offs are fan and pump power, room airflow, and the need to remove the heat from the data center. Liquid-to-air does not eliminate facility cooling; it changes where the heat is transferred.
Best Value
- High-Speed Ceramic Bearing Pump: Our 360mm AIO is equipped with a premium ceramic bearing water pump running at 3000 RPM, ensuring ultra-long lifespan and stable operation, offering higher lift and faster flow for maximum cooling efficiency. Our CPU cooler delivers reliable performance even under heavy workloads, keeping your system cool and stable.
- Industrial-Grade Motor for Elite Cooling: Our AIO cooler 360mm is powered by an advanced 3-phase, 4-pole motor that minimizes vibration and noise for ultra-smooth, silent operation. Our cpu water cooler accelerates heat transfer and boosts coolant flow to maximize thermal performance, ensuring greater efficiency and long-term reliability.
- Smart PWM Fan Control for Quiet Efficiency: Our water cooler CPU is equipped with PWM-controlled fans that automatically adjust their speed based on your system’s temperature, delivering optimal airflow only when needed. Running at up to 1600 RPM, these fans offer a perfect balance of high airflow and low noise, making our cpu liquid cooler ideal for gamers, creators, and power users alike.
- Exclusive 12-Channel Radiator for Superior Heat Dissipation: Our CPU liquid cooler features a 12-path water-cooled radiator with a low-resistance hydraulic design and optimized fin density, maximizing surface contact for faster heat transfer and enhanced cooling performance.
- Daisy-Chained Fans for Cleaner, Simpler Cable Management: Our 360mm aio cooler comes with pre-installed 120mm fans featuring a daisy-chain design, allowing all fans to connect through a single 4-pin PWM and 5V ARGB header—dramatically reducing cable clutter and simplifying installation.
The CHx500 can concentrate more heat-transfer capacity in a rack and may support warm-water operation, reduced chiller dependence, or heat reuse when the whole facility is designed for it. It also shifts more responsibility to the water system: water chemistry, temperature and pressure limits, filtration, leak detection, isolation, and plant-level redundancy all need engineering. A CDU capacity rating is not a rating for the entire cooling plant.
Questions to resolve before specifying one
- What capacity is guaranteed at the project’s actual supply and return temperatures, and exactly how is the stated approach defined?
- What flow and pressure must be available at the rack manifold? What are the pressure drops through the CDU, piping, manifolds, and cold plates?
- What is total electrical draw at partial and full load, including fans and pumps, and what electrical service and backup are required?
- Which components have N+1 or 2N redundancy? Are power feeds and controls independent, and what happens after pump, fan, controller, or sensor failure?
- What coolant is approved? What filtration, water chemistry, corrosion control, and maintenance intervals are required?
- For a CHx500 deployment, what facility-water temperature, flow, and pressure are required, and what plant equipment is outside the CDU?
- How do leak detection, alarm handling, automatic isolation, and maintenance bypasses work? What failures can still cause a system-wide shutdown?
- Which server OEM, cold plates, and manifolds are validated for the proposed configuration? What rack power and workload underpin any rack-count claim?
- What commissioning tests, spare-parts arrangements, service coverage, installation scope, and lead times apply to this geography and configuration?
Redundancy labels alone do not establish end-to-end resilience. A shared power source, common controller, failed heat exchanger, unavailable facility water, or leak response can remain a single point of failure. Evaluate the complete loop and failure response, not just the number of pumps.
Where the lineup stands now
The AHx180 and AHx240 remain on CoolIT’s public product pages, while its current CDU portfolio also emphasizes newer CHx models, including the CHx200 and CHx2000. The CHx500 should therefore be understood as one of the products in the 2024 launch, not assumed to be CoolIT’s current flagship liquid-to-liquid unit. Product pages and supported-platform claims can change; check the current CDU portfolio and confirm configuration and availability directly.
CoolIT’s public pages do not provide a broadly applicable purchase price. These are enterprise systems whose quotes may depend on capacity, controls, options, integration, commissioning, spares, and service. A buyer should treat the CDU as part of a systems-engineering and lifecycle-support purchase, not a commodity device with a simple retail price. The available launch coverage is announcement-based; it does not establish independently measured efficiency, noise, reliability, PUE impact, or real-world cooling performance.
Bottom line
The AHx180 and AHx240 target sites that want direct liquid cooling while rejecting heat to air rather than adding a facility-water loop. The CHx500 targets facilities with liquid infrastructure and larger aggregate loads. These products address different facility constraints, so the useful comparison is not simply 180 versus 240 versus 500 kW: it is which heat-rejection architecture, operating conditions, and redundancy design the site can support.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
