AIO Radiator Compatibility: Will a 240, 280 or 360 mm Cooler Fit?

A size label is not the radiator's full length

The familiar 240, 280 and 360 mm labels describe fan-size arrangements rather than every external dimension. End tanks and fittings extend beyond the fan area. ARCTIC's Liquid Freezer III 360 specification, for example, lists a radiator measuring 398 × 120 × 38 mm. Check the dimensions for the exact variant, including Pro or RGB suffixes. A case supporting three 120 mm fans does not automatically support every 360 mm radiator in that same position.

Select a mounting location before comparing products

Read the case manual's separate front, top, side and rear allowances. Corsair's 4000D guidance supports different radiator arrangements at the front and roof; its quick-start guide specifically qualifies top-mounted 280 mm support with CORSAIR LPX memory. That wording does not certify every kit sold as low profile. A general product-page list containing 360 mm also does not mean a 360 mm radiator belongs in the roof. Write the intended mounting position beside the cooler in your plan.

Check the radiator-and-fan stack

Account for the radiator, the specified fans and anything else that occupies the same depth, such as a bracket or protruding fittings. Compare the assembly drawing with the case's clearance diagram. At the roof, examine RAM heatspreaders, motherboard power heatsinks and the CPU-power cable route. A thick radiator may share the same nominal size as a thinner one but require more room. Do not substitute a bare radiator measurement for the complete installed assembly, especially when considering fans on both sides.

Recalculate GPU space for a front radiator

A front-mounted AIO can occupy space otherwise available to a long graphics card. Determine where the radiator and fans sit relative to the case's published GPU measurement. Some brackets position part of the assembly outside the main compartment; others place all of it inside. Use the documented remaining clearance rather than applying an automatic subtraction to an unexplained headline number. Check that the hoses can pass the card and reach the CPU block without being pulled tight or trapped by the panel.

Check socket support and block clearance separately

Even when the radiator fits, the pump or cold-plate assembly needs the correct socket hardware and clearance around the motherboard. Consult the cooler's board-compatibility information and required mounting parts. Check nearby M.2 heatsinks or other raised components where the manufacturer flags them. List required fan, pump, USB or controller connections before ordering. A cooler with enough physical room can still require a controller or header arrangement that has not been included in the build.

Follow the instructions for the pump's actual location

Corsair's guidance for AIOs with a CPU-block pump aims to keep the top of the radiator above the pump so air can collect away from it. It describes top mounting and front mounting with appropriate tube routing. Do not apply a diagram blindly to an AIO whose pump sits in a different place; use that model's manual. Prefer a documented arrangement that reaches naturally over one that requires strained hoses, and avoid treating tube direction alone as the entire compatibility check.

Decide what to change when a measurement fails

If a top radiator overlaps RAM, investigate another supported position, a thinner approved assembly, different memory or another case. If moving it to the front blocks the GPU, compare a shorter card variant or revise the cooling choice. Recheck all affected dimensions after the change. Do not use longer improvised radiator screws, force the case bracket or bend tubing sharply to rescue a poor fit. Keep the manufacturer's mounting hardware and instructions with the final parts list for assembly day.

Your checklist

• Exact radiator dimensions and mounting position recorded.
• Complete radiator-and-fan stack checked.
• RAM, motherboard heatsinks and GPU checked in the same layout.
• Socket hardware, controller connections and tube reach confirmed.
• Pump placement follows the exact AIO manual.