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

A size label is not the radiator's full length

The 240, 280 and 360 mm labels refer to fan arrangements, not the radiator's full external dimensions. ARCTIC's Liquid Freezer III 360, for example, has a 398 × 120 × 38 mm radiator. End tanks and fittings extend beyond the fan area. Look up the exact variant, including any Pro or RGB suffix. Three 120 mm fan positions do not automatically provide space for every radiator marketed as 360 mm.

Select a mounting location before comparing products

Read the separate front and roof limits in the case manual. Corsair's 4000D guide gives different arrangements for those locations and qualifies top-mounted 280 mm support with CORSAIR LPX memory. It does not certify every kit described as low profile. Likewise, 360 mm support somewhere in the case does not mean 360 mm roof support. Decide on a position before comparing AIOs, otherwise you may be comparing products for a mount you cannot use.

Check the radiator-and-fan stack

Add the specified fans to the radiator thickness and inspect the drawing for brackets or fittings that occupy the same space. At the roof, compare that stack with the RAM, motherboard power heatsinks and CPU-power cable route. Two AIOs with the same nominal radiator size can need different depths. Fans on both sides add another layer to this check. Use the installed assembly, not the bare radiator, when judging clearance.

A worked roof layout: Pop 2 Air and Liquid Freezer III Pro 360

Take the Pop 2 Air Black Solid (FD-C-POA2A-01), the black Liquid Freezer III Pro 360 A-RGB (ACFRE00184A), an MSI B650 GAMING PLUS WIFI and a Flare X5 32 GB kit (F5-6000J3038F16GX2-FX5). Use the horizontal MSI RTX 5070 VENTUS 2X OC from the GPU example, keep the three front case fans and mount the AIO at the roof. These exact suffixes matter: Pop Air, Pop 2 Vision and a 280 mm Liquid Freezer have different limits.

The length, width and RAM-height comparisons below meet the published limits. They do not prove the assembled radiator and fans clear the board's upper heatsinks and cables: ARCTIC's drawing marks the full assembly at 66 mm, even though the separate 38 mm and 25 mm dimensions add to 63 mm. Use the larger drawn envelope for the clearance check. The 1 mm radiator-width difference is also a nominal allowance, not a measured gap. Keep the roof layout as a candidate until those remaining clearances are confirmed. We have not assembled or temperature-tested this combination.

Finish this layout before buying the AIO

The named board clears the manufacturer's block-compatibility check. The remaining question is its upper VRM heatsinks and CPU-power lead beneath the 66 mm roof assembly. A RAM module passing the 47 mm limit does not settle that. Confirm the occupied space with the case and cooler support teams or a physical clearance check. If it conflicts, compare a thinner 360/240 mm cooler at the roof or change the case; the unsupported front mount is not an alternative.

With the machine unplugged, plan the CPU-power cable route before the radiator closes off access. Follow the AIO's AM5 mounting instructions, use its supplied screws and check that the 450 mm hoses can reach without tension. For wiring, choose either the all-in-one PWM cable or the separate pump, VRM-fan and radiator-fan controls described in the manual. Check the chosen headers' current limits. Connect the lighting only to a compatible 5 V three-pin ARGB header or controller, never a 12 V RGB header.

The first powered check is whether the connected fans and pump operate and the CPU temperature remains controlled at stock settings. This model's all-in-one lead reports pump speed; that reading does not prove every fan is running. Complete those checks before tuning curves or claiming the layout performs well.

Recalculate GPU space for a front radiator

At the front, the AIO can take space from the graphics card. Find where the radiator and fans sit relative to the case's GPU measurement: some brackets move part of the stack outside the main compartment. Use a documented remaining clearance rather than subtracting from a maximum whose starting point is unclear. Trace the hoses past the card too. They need to reach the block without being pulled tight or pinched by a panel.

Check socket support and block clearance separately

The radiator fitting does not settle the CPU end of the installation. Verify the socket kit and read any board-specific clearance notes, especially around raised M.2 heatsinks or other components near the block. Next, count the AIO's pump, fan, USB and controller connections. Resolve a missing header or controller before ordering; enough physical space will not provide the connections the cooler needs.

Follow the instructions for the pump's actual location

For AIOs with the pump at the CPU block, Corsair's guidance keeps the radiator's highest point above the pump so air can collect away from it. It covers top and front installations with suitable tube routing. If your AIO puts the pump elsewhere, follow that model's manual instead. Choose a supported layout with a natural hose route; changing which way the tubes point does not compensate for a badly placed pump or strained hose.

Decide what to change when a measurement fails

If the roof assembly hits the RAM, compare another supported position, a thinner suitable cooler, shorter memory or a different case. Moving to the front may solve that conflict while creating a GPU conflict, so check both before buying. Use the supplied mounting hardware. Longer improvised screws, forced brackets and sharply bent hoses are not fixes for the wrong dimensions.

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.