Air Coolers vs AIO Liquid Coolers: The 2026 Thermal Showdown

Determine the true winner between air coolers and AIO liquid cooling systems based on 2026 thermal standards, reliability, and acoustic performance.

Our Top Products Picks

Noctua NH-D15 G2 chromax.Black Premium Dual Tower CPU Cooler for AMD AM5/AM4 and Intel LGA1851/LGA1700/LGA1200 (Black)

Noctua NH-D15 G2 chromax.Black Premium Dual Tower CPU Cooler for AMD AM5/AM4 and Intel LGA1851/LGA1700/LGA1200 (Black)

Noctua

Further improved second generation of the iconic, award-winning NH-D15: Even better quiet cooling performance thanks to 8 heatpipes, 20% more surface area and novel NF-A14x25r G2 fans! All-black chromax version, ideal for AMD Ryzen (e.g. 9800X3D, 9950X3D, 9900X3D, 9950X, 7950X, 7800X3D, 5800X3D) and Intel Core or Core Ultra CPUs (e.g. 285K, 265K, 245K, 14900K, 13900K, 12900K) Two state-of-the-art NF-A14x25r G2 140mm fans with speed-offset for acoustic fine-tuning, Low-Noise Adaptors and PWM for automatic speed control: maximum efficiency under load, near silent at idle! Offset design with recessed lower fins clears top PCIe x16 on most current motherboards and offers 59mm RAM clearance in single fan mode (32mm with both fans, see Noctua Compatibility Centre) Includes superior NT-H2 thermal paste and Torx-based SecuFirm2+ mounting system with NM-SD1 screwdriver for easy installation on AMD AM5 & AM4 as well as Intel LGA1851, LGA1700, LGA1200 & LGA115x

CORSAIR Titan 360 RX LCD Liquid CPU Cooler, 360mm AIO, Low-Noise FlowDrive Cooling Engine, Intel LGA 1851/1700 & AMD AM5/AM4, 3X RX120 RGB Fans, System Hub Included, Black

CORSAIR Titan 360 RX LCD Liquid CPU Cooler, 360mm AIO, Low-Noise FlowDrive Cooling Engine, Intel LGA 1851/1700 & AMD AM5/AM4, 3X RX120 RGB Fans, System Hub Included, Black

Corsair

All-in-One CPU Cooling Made Easy with iCUE LINK: High-performance, low-noise AIO cooling helps you get the most out of your CPU, taking advantage of the iCUE LINK ecosystem for simplified, streamlined connections. Brilliant IPS LCD Display: Showcase your real-time CPU temperature, favorite animated GIF, funniest meme, or your team’s logo on a custom 2.1” IPS LCD screen with 480x480 resolution, ultra-bright 600cd/m² backlight, 30 FPS, and over 16.7 million colors. Effortless Connectivity and Intelligent Design: iCUE LINK technology lets you connect all your components in sequence using universal connectors, all plugged into a single port on the included iCUE LINK System Hub. Build faster, reduce cable clutter, and create a more intelligent, cohesive system setup. FlowDrive Cooling Engine: A performance pump powered by a three-phase motor, combined with a precision engineered cold plate surface profile to ensure maximum contact with your CPU’s integrated heat spreader, form CORSAIR’s ultra-efficient FlowDrive engine. Pre-Mounted iCUE LINK RX RGB Fans: RX RGB fans are specifically engineered for high airflow and static pressure, excelling as radiator cooling fans. CORSAIR AirGuide technology and Magnetic Dome bearings deliver unrivaled cooling performance and low noise. Compatible with Intel 1851, Intel 1700, AMD AM5, AMD AM4.

ARCTIC Liquid Freezer III Pro 360 - AIO CPU Cooler, 3 x 120 mm Water Cooling, 38 mm Radiator, PWM Pump, VRM Fan, AMD AM5/AM4, Intel LGA1851/1700 Contact Frame - Black

ARCTIC Liquid Freezer III Pro 360 - AIO CPU Cooler, 3 x 120 mm Water Cooling, 38 mm Radiator, PWM Pump, VRM Fan, AMD AM5/AM4, Intel LGA1851/1700 Contact Frame - Black

ARCTIC

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

Thermalright Peerless Assassin 120 SE CPU Cooler, 6 Heat Pipes AGHP Technology, Dual 120mm PWM Fans, 1550RPM Speed, for AMD:AM4 AM5/Intel LGA 1700/1150/1151/1200/1851,PC Cooler

Thermalright Peerless Assassin 120 SE CPU Cooler, 6 Heat Pipes AGHP Technology, Dual 120mm PWM Fans, 1550RPM Speed, for AMD:AM4 AM5/Intel LGA 1700/1150/1151/1200/1851,PC Cooler

Thermalright

[Brand Overview] Thermalright is a Taiwan brand with more than 20 years of development. It has a certain popularity in the domestic and foreign markets and has a pivotal influence in the player market. We have been focusing on the research and development of computer accessories. R & D product lines include: CPU air-cooled radiator, case fan, thermal silicone pad, thermal silicone grease, CPU fan controller, anti falling off mounting bracket, support mounting bracket and other commodities [Product specification] Thermalright PA120 SE; CPU Cooler dimensions: 125(L)x135(W)x155(H)mm (4.92x5.31x6.1 inch); heat sink material: aluminum, CPU cooler is equipped with metal fasteners of Intel & AMD platform to achieve better installation, double tower cooling is stronger((Note:Please check your case and motherboard for compatibility with this size cooler.) 【2 PWM Fans】TL-C12C; Standard size PWM fan:120x120x25mm (4.72x4.72x0.98 inches); fan speed (RPM):1550rpm±10%; power port: 4pin; Voltage:12V; Air flow:66.17CFM(MAX); Noise Level≤25.6dB(A), leave room for memory-chip(RAM), so that installation of ice cooler cpu is unrestricted 【AGHP technique】6×6mm heat pipes apply AGHP technique, Solve the Inverse gravity effect caused by vertical / horizontal orientation, 6 pure copper sintered heat pipes & PWM fan & Pure copper base&Full electroplating reflow welding process, When CPU cooler works, match with pwm fans, aim to extreme CPU cooling performance 【Compatibility】The CPU cooler Socket supports: Intel:115X/1200/1700/17XX AMD:AM4;AM5; For different CPU socket platforms, corresponding mounting plate or fastener parts are provided(Note: Toinstall the AMD platform, you need to use the original motherboard's built-in backplanefor installation, which is not included with this product)

Choosing between air coolers vs AIO liquid coolers dictates the acoustic profile, aesthetic, and performance ceiling of your entire system. As we settle into 2026, high-end CPUs from both Intel and AMD are pushing aggressive thermal targets, making your choice of PC thermal management more critical than older models from 2024.

Building a whisper-quiet PC requires the same meticulous planning as a high-end audio room. We apply many of the same acoustic principles found in The Ultimate Home Theater Setup Guide: From Design to Calibration to isolate pump hum and fan turbulence. While older generation hardware allowed builders to skate by with mediocre heatsinks, current market standards demand precision.

Key Takeaways

  • Winner for Reliability: Air coolers take the crown with zero points of mechanical failure beyond replaceable fans.
  • Winner for Peak Performance: 360mm and 420mm AIOs dominate high-wattage transient spikes on flagship CPUs.
  • Winner for Value: Dual-tower air coolers deliver 90% of the performance of premium AIOs for half the price.
  • Winner for Aesthetics: AIOs provide cleaner internal layouts and unobstructed RAM visibility.

The 2026 Verdict: Feature-by-Feature Breakdown

The 2026 Verdict: Feature-by-Feature Breakdown

Before analyzing the deep technical nuances, we must establish exactly where each cooling solution excels. The current market standards clearly divide these two technologies into specific ideal use cases.

Feature CategoryAir Cooling ChampionAIO Liquid Cooling ChampionUltimate Winner
Thermal CapacityExcellent up to 250WSuperior above 250WAIO Liquid Coolers
Acoustic ProfileConsistent, low frequencyHighly variable, pump noiseAir Coolers
Lifespan10+ years (fan swaps only)5-7 years (permeation)Air Coolers
RAM ClearanceOften obstructedFully unobstructedAIO Liquid Coolers
Price-to-PerformanceExceptional under $50Diminishing returns over $150Air Coolers

For budget and mid-tier builds, heavy-duty air cooling definitively wins. For flagship enthusiast builds utilizing cases with massive radiator support, AIOs take the crown.

Thermal Performance and Heat Dissipation

Thermal Performance and Heat Dissipation

Modern 2026 processors feature aggressive boosting algorithms that spike temperatures instantly. AIO liquid coolers handle these sudden transient thermal loads better due to the specific heat capacity of the liquid medium. The coolant absorbs heat spikes before the fans even need to spin up, flattening the temperature curve.

Premium dual-tower air coolers rely entirely on conductive heat transfer through copper heat pipes to aluminum fins. While units like the Noctua NH-D15 G2 process sustained loads brilliantly, they lack the thermal buffering of a liquid loop. Once the metal is saturated, the fans must aggressively ramp up to dissipate the energy.

If you run heavily multithreaded rendering workloads or compile code for hours, a 360mm AIO maintains a lower equilibrium temperature. For bursty gaming workloads, the performance delta between a top-tier air cooler and a premium AIO shrinks to a negligible 2-4 degrees Celsius.

Acoustics: Fan Turbulence vs Pump Whine

Raw decibel output only tells half the acoustic story. The frequency pitch determines how annoying a sound is to the human ear.

Air coolers produce a natural, lower-frequency whoosh of air passing through aluminum fins. At idle, premium air coolers are practically silent. However, under load, dual 140mm fans spinning at 1500 RPM generate noticeable turbulence.

An AIO liquid cooler introduces pump mechanics into the equation. While radiator fans can spin slower due to massive surface area, the pump block emits a high-pitched mechanical hum. This high-frequency whine easily pierces through the sound dampening of modern cases. If your priority is an absolutely silent idle experience, a massive air cooler with custom fan curves remains the superior choice.

Motherboard Form Factors and Installation Clearances

Your choice of motherboard form factor heavily restricts your cooling options. Standard ATX motherboards offer breathing room, but as you scale down to Micro-ATX and Mini-ITX, clearance becomes a massive hurdle.

Massive air coolers frequently overlap memory slots. If you purchase high-profile RGB DDR5 RAM, a dual-tower heatsink will force you to mount the front fan higher, ruining the aesthetic and reducing case side-panel clearance. Furthermore, reaching the primary PCIe slot release latch with a giant block of metal in the way requires surgical precision.

AIOs solve this motherboard congestion immediately. The CPU block is incredibly low-profile, ensuring 100% RAM compatibility and easy access to M.2 slots. The trade-off is moving the bulk of the cooling mass to the edges of your case, which requires verifying exact radiator thickness and fan clearance against your specific chassis manual.

Reliability, Lifespan, and Catastrophic Failure Risk

When evaluating long-term 2026 value, reliability metrics heavily favor one side. An air cooler is just a chunk of engineered metal. The only moving parts are the fans. If a fan dies five years from now, you spend $20, clip on a replacement, and your cooler performs identically to day one.

AIOs are complex mechanical systems constrained by physics. Over time, liquid permeation occurs-meaning coolant slowly evaporates through the microscopic pores of the rubber tubing. Most AIOs lose optimal efficiency within 5 to 7 years. Additionally, if the internal pump fails or the micro-fins clog with galvanic corrosion debris, the entire unit becomes e-waste. While modern AIO leaks are exceptionally rare, the pump's inevitable death gives air coolers the undisputed victory for longevity.

The decision between these two thermal philosophies comes down to a balance of aesthetics, budget, and risk tolerance. Heavy-duty air coolers remain the undefeated champions of value and reliability, offering massive cooling potential for a fraction of the price of liquid systems. They are the logical choice for builders who want to assemble their PC and never think about maintenance for the next decade.

Conversely, AIO liquid coolers justify their premium pricing through superior thermal buffering on flagship processors and undeniably cleaner aesthetics. If your build utilizes a windowed case and high-end components where every degree and visual detail matters, a modern 360mm AIO is the required tool for the job. Evaluate your case clearance, match the thermal ceiling to your CPU tier, and choose the solution that best fits your specific computing environment.

Our Top Picks

Noctua NH-D15 G2 chromax.Black Premium Dual Tower CPU Cooler for AMD AM5/AM4 and Intel LGA1851/LGA1700/LGA1200 (Black)
Noctua

Noctua NH-D15 G2 chromax.Black Premium Dual Tower CPU Cooler for AMD AM5/AM4 and Intel LGA1851/LGA1700/LGA1200 (Black)

Further improved second generation of the iconic, award-winning NH-D15: Even better quiet cooling performance thanks to 8 heatpipes, 20% more surface area and novel NF-A14x25r G2 fans! All-black chromax version, ideal for AMD Ryzen (e.g. 9800X3D, 9950X3D, 9900X3D, 9950X, 7950X, 7800X3D, 5800X3D) and Intel Core or Core Ultra CPUs (e.g. 285K, 265K, 245K, 14900K, 13900K, 12900K) Two state-of-the-art NF-A14x25r G2 140mm fans with speed-offset for acoustic fine-tuning, Low-Noise Adaptors and PWM for automatic speed control: maximum efficiency under load, near silent at idle! Offset design with recessed lower fins clears top PCIe x16 on most current motherboards and offers 59mm RAM clearance in single fan mode (32mm with both fans, see Noctua Compatibility Centre) Includes superior NT-H2 thermal paste and Torx-based SecuFirm2+ mounting system with NM-SD1 screwdriver for easy installation on AMD AM5 & AM4 as well as Intel LGA1851, LGA1700, LGA1200 & LGA115x

Key Features

  • Further improved second generation of the iconic, award-winning NH-D15: Even better quiet cooling performance thanks to 8 heatpipes, 20% more surface area and novel NF-A14x25r G2 fans!
  • All-black chromax version, ideal for AMD Ryzen (e.g. 9800X3D, 9950X3D, 9900X3D, 9950X, 7950X, 7800X3D, 5800X3D) and Intel Core or Core Ultra CPUs (e.g. 285K, 265K, 245K, 14900K, 13900K, 12900K)
  • Two state-of-the-art NF-A14x25r G2 140mm fans with speed-offset for acoustic fine-tuning, Low-Noise Adaptors and PWM for automatic speed control: maximum efficiency under load, near silent at idle!
  • Offset design with recessed lower fins clears top PCIe x16 on most current motherboards and offers 59mm RAM clearance in single fan mode (32mm with both fans, see Noctua Compatibility Centre)

Specifications

Unit Count1
$184.95
Check on Amazon
Free delivery available • Prime eligible
CORSAIR Titan 360 RX LCD Liquid CPU Cooler, 360mm AIO, Low-Noise FlowDrive Cooling Engine, Intel LGA 1851/1700 & AMD AM5/AM4, 3X RX120 RGB Fans, System Hub Included, Black
Corsair

CORSAIR Titan 360 RX LCD Liquid CPU Cooler, 360mm AIO, Low-Noise FlowDrive Cooling Engine, Intel LGA 1851/1700 & AMD AM5/AM4, 3X RX120 RGB Fans, System Hub Included, Black

All-in-One CPU Cooling Made Easy with iCUE LINK: High-performance, low-noise AIO cooling helps you get the most out of your CPU, taking advantage of the iCUE LINK ecosystem for simplified, streamlined connections. Brilliant IPS LCD Display: Showcase your real-time CPU temperature, favorite animated GIF, funniest meme, or your team’s logo on a custom 2.1” IPS LCD screen with 480x480 resolution, ultra-bright 600cd/m² backlight, 30 FPS, and over 16.7 million colors. Effortless Connectivity and Intelligent Design: iCUE LINK technology lets you connect all your components in sequence using universal connectors, all plugged into a single port on the included iCUE LINK System Hub. Build faster, reduce cable clutter, and create a more intelligent, cohesive system setup. FlowDrive Cooling Engine: A performance pump powered by a three-phase motor, combined with a precision engineered cold plate surface profile to ensure maximum contact with your CPU’s integrated heat spreader, form CORSAIR’s ultra-efficient FlowDrive engine. Pre-Mounted iCUE LINK RX RGB Fans: RX RGB fans are specifically engineered for high airflow and static pressure, excelling as radiator cooling fans. CORSAIR AirGuide technology and Magnetic Dome bearings deliver unrivaled cooling performance and low noise. Compatible with Intel 1851, Intel 1700, AMD AM5, AMD AM4.

Key Features

  • All-in-One CPU Cooling Made Easy with iCUE LINK: High-performance, low-noise AIO cooling helps you get the most out of your CPU, taking advantage of the iCUE LINK ecosystem for simplified, streamlined connections.
  • Brilliant IPS LCD Display: Showcase your real-time CPU temperature, favorite animated GIF, funniest meme, or your team’s logo on a custom 2.1” IPS LCD screen with 480x480 resolution, ultra-bright 600cd/m² backlight, 30 FPS, and over 16.7 million colors.
  • Effortless Connectivity and Intelligent Design: iCUE LINK technology lets you connect all your components in sequence using universal connectors, all plugged into a single port on the included iCUE LINK System Hub. Build faster, reduce cable clutter, and create a more intelligent, cohesive system setup.
  • FlowDrive Cooling Engine: A performance pump powered by a three-phase motor, combined with a precision engineered cold plate surface profile to ensure maximum contact with your CPU’s integrated heat spreader, form CORSAIR’s ultra-efficient FlowDrive engine.

Specifications

ColorBlack
Size360mm AIO
Unit Count1
$194.99
Check on Amazon
Free delivery available • Prime eligible
ARCTIC Liquid Freezer III Pro 360 - AIO CPU Cooler, 3 x 120 mm Water Cooling, 38 mm Radiator, PWM Pump, VRM Fan, AMD AM5/AM4, Intel LGA1851/1700 Contact Frame - Black
ARCTIC

ARCTIC Liquid Freezer III Pro 360 - AIO CPU Cooler, 3 x 120 mm Water Cooling, 38 mm Radiator, PWM Pump, VRM Fan, AMD AM5/AM4, Intel LGA1851/1700 Contact Frame - Black

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

Key Features

  • 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

Specifications

ColorPro - Black
Unit Count1
$89.99
Check on Amazon
Free delivery available • Prime eligible
Thermalright Peerless Assassin 120 SE CPU Cooler, 6 Heat Pipes AGHP Technology, Dual 120mm PWM Fans, 1550RPM Speed, for AMD:AM4 AM5/Intel LGA 1700/1150/1151/1200/1851,PC Cooler
Thermalright

Thermalright Peerless Assassin 120 SE CPU Cooler, 6 Heat Pipes AGHP Technology, Dual 120mm PWM Fans, 1550RPM Speed, for AMD:AM4 AM5/Intel LGA 1700/1150/1151/1200/1851,PC Cooler

[Brand Overview] Thermalright is a Taiwan brand with more than 20 years of development. It has a certain popularity in the domestic and foreign markets and has a pivotal influence in the player market. We have been focusing on the research and development of computer accessories. R & D product lines include: CPU air-cooled radiator, case fan, thermal silicone pad, thermal silicone grease, CPU fan controller, anti falling off mounting bracket, support mounting bracket and other commodities [Product specification] Thermalright PA120 SE; CPU Cooler dimensions: 125(L)x135(W)x155(H)mm (4.92x5.31x6.1 inch); heat sink material: aluminum, CPU cooler is equipped with metal fasteners of Intel & AMD platform to achieve better installation, double tower cooling is stronger((Note:Please check your case and motherboard for compatibility with this size cooler.) 【2 PWM Fans】TL-C12C; Standard size PWM fan:120x120x25mm (4.72x4.72x0.98 inches); fan speed (RPM):1550rpm±10%; power port: 4pin; Voltage:12V; Air flow:66.17CFM(MAX); Noise Level≤25.6dB(A), leave room for memory-chip(RAM), so that installation of ice cooler cpu is unrestricted 【AGHP technique】6×6mm heat pipes apply AGHP technique, Solve the Inverse gravity effect caused by vertical / horizontal orientation, 6 pure copper sintered heat pipes & PWM fan & Pure copper base&Full electroplating reflow welding process, When CPU cooler works, match with pwm fans, aim to extreme CPU cooling performance 【Compatibility】The CPU cooler Socket supports: Intel:115X/1200/1700/17XX AMD:AM4;AM5; For different CPU socket platforms, corresponding mounting plate or fastener parts are provided(Note: Toinstall the AMD platform, you need to use the original motherboard's built-in backplanefor installation, which is not included with this product)

Key Features

  • [Brand Overview] Thermalright is a Taiwan brand with more than 20 years of development. It has a certain popularity in the domestic and foreign markets and has a pivotal influence in the player market. We have been focusing on the research and development of computer accessories. R & D product lines include: CPU air-cooled radiator, case fan, thermal silicone pad, thermal silicone grease, CPU fan controller, anti falling off mounting bracket, support mounting bracket and other commodities
  • [Product specification] Thermalright PA120 SE; CPU Cooler dimensions: 125(L)x135(W)x155(H)mm (4.92x5.31x6.1 inch); heat sink material: aluminum, CPU cooler is equipped with metal fasteners of Intel & AMD platform to achieve better installation, double tower cooling is stronger((Note:Please check your case and motherboard for compatibility with this size cooler.)
  • 【2 PWM Fans】TL-C12C; Standard size PWM fan:120x120x25mm (4.72x4.72x0.98 inches); fan speed (RPM):1550rpm±10%; power port: 4pin; Voltage:12V; Air flow:66.17CFM(MAX); Noise Level≤25.6dB(A), leave room for memory-chip(RAM), so that installation of ice cooler cpu is unrestricted
  • 【AGHP technique】6×6mm heat pipes apply AGHP technique, Solve the Inverse gravity effect caused by vertical / horizontal orientation, 6 pure copper sintered heat pipes & PWM fan & Pure copper base&Full electroplating reflow welding process, When CPU cooler works, match with pwm fans, aim to extreme CPU cooling performance

Specifications

ColorPA120 SE
SizePA120 SE series
Unit Count3
$34.90
Check on Amazon
Free delivery available • Prime eligible

Frequently Asked Questions

Do AIO liquid coolers leak?
While technically possible, catastrophic leaks in modern 2026 AIOs are incredibly rare. Manufacturers utilize multi-layer sleeved tubing and strictly regulated pressure valves. The most common failure is a dead pump, not a fluid leak.
Can a premium air cooler handle an Intel Core i9 or Ryzen 9?
Yes, top-tier dual-tower air coolers can handle flagship CPUs under gaming loads. However, during sustained 100% synthetic utilization, an air cooler will force the CPU to thermally throttle slightly earlier than a 360mm AIO.
How often do I need to refill an AIO liquid cooler?
You do not refill an AIO (All-In-One). They are closed-loop systems designed to operate without maintenance. Once permeation significantly reduces the liquid level after 5-7 years, the entire unit is typically replaced.
Does an AIO or an air cooler consume more power?
An AIO consumes slightly more power because the motherboard must power both the radiator fans and the continuous operation of the liquid pump. However, the total draw is usually under 15 watts, which is negligible for modern power supplies.
Will a large air cooler damage my motherboard during transport?
Heavy air coolers place significant stress on the motherboard socket. If you are moving or shipping your PC, it is highly recommended to remove heavy tower coolers, whereas an AIO block places almost no torque on the motherboard.