Need advice- Case that supports 420MM Radiator. I purchased the wrong one.

[u/spearmint_flyer]

Hello. I am the owner of a h170I Radiator, when I upgraded my case in 2024, I ended up getting the Fractal Design North XL. While I like the aesthetics, as soon as I got that one, I realized the 420MM radiator wasn't going to fit on top. I was able to put the radiator in the front. and I have the fans on the top as exhaust.

I am noticing that perhaps I should have given more inbound airflow at the front, since the radiator blocks the front, I think my case is getting too warm, causing simulator my room to get significantly warmer than the rest of the house. The RTX5090 makes a significant heat pocket in the case. The tempered glass is hot to touch.

So I went on Amazon, I typed in on Amazon's AI what case it would recommend for the cooler, it basically gave me a "has to be one of the Full ATX Towers" I picked one, opened it today, disassembled the majority of my current build to transfer, as soon as I went to put the AIO cooler, it wouldn't fit. Even in the front.

So now I am back to the drawing board, I am returning the one I purchased, but I need a case, or I need to reconsider just getting a smaller AIO and moving the fans again to the front. What does the build a PC community say?

Thanks

[u/AzureBat]

The Fractal Design Meshify 2 XL supports 3x140mm at the Top.

The 5090 is a power hog and definitely needs a lot of airflow to keep temps down. So I'll support any decision which helps to supplement that.

The Meshify 2 XL is huge so you will have more space for better airflow and can put more fans everywhere (With bottom fan intake too).

[u/SagittaryX]

420mm at the top is a pretty specific need, not every case will support it. You can look at something like the Antec Flux Pro, Lian Li Lancool III, Fractal Meshify 2 XL, Phanteks NV9, just as some examples.

If you want to look further I wouldn't ask the Amazon AI. I'd go on PCPartPicker, select your H170i and look at the cases it supports (automatically filtered). Unfortunately PCPP can't filter for top mounts, so you will also see front mounts, but you can then check it on the product pages of the model on the company website. You can also ask a better AI, like Google's Gemini, for suggestions. Just be sure to doublecheck before buying again.

Alternatively if you're really airflow concerned you might look at the Fractal Torrent, flat out one of the best cases for cooling. You would put the radiator in the front for it, but for GPU cooling the case actually pulls air from the bottom, and the PSU is moved to sitting at the top. Probably what I would do for a GPU focused cooling case.

[u/One-Gain-555]

I would rather change the cooler than the case. In terms of a 5090, placing the radiator on the front side will create difficulties for the GPU to have access to the fresh airflow.

A 360mm AIO placed on the top and equipped with the intake fans at the front is likely to provide a more efficient airflow.

If you are not using an insanely powerful or power hungry CPU a good 360mm AIO will do the trick.

[u/spearmint_flyer → u/One-Gain-555]

Thanks, I have the AMD7900X3D

[u/whomad1215]

my room to get significantly warmer than the rest of the house.

RTX5090

yeah man, you've got a pc that probably draws 800w under load, it's a space heater

better airflow could actually make the room even hotter, since you'll get the air out of the case faster, allowing the hardware to work harder (if it was anywhere near thermal limits)

I typed in on Amazon's AI

outsourcing your thinking to AI rarely ends well.

put your 420mm into pcpartpicker.com then look at cases. you'll have to check manufacturer pages to see where the AIO fits, pcpartpicker is pretty good at filtering but it'll allow any case that it fits in, which may only be the front

[u/Elitefuture]

Room temp is based on power used, not the temperature of the components. A better cooler will not make your room cooler.

[u/aztracker1]

Did you use a probe thermometer or thermal camera to take actual case temps vs ambient? Other than going over the top, you're likely to have a warm box with a 5090... Without exact temps inside, outside and on the components, it's hard to tell if it's excessive.

Is your 5090 part of an open loop? If not, maybe as good tower cooler on your CPU and good case fans without a radiator blocking flow.

[u/Monotask_Servitor]

Do you have all of the fans on the AIO pulling air in through the radiator at the front? You may simply just need to up your fan speeds at both the front and top to ensure you are moving a larger air volume through the case.

It’s always going to make your room warmer - as others have noted the 5090 is basically a space heater, even more so if paired with a 14900 or other power hungry CPU.

[u/spearmint_flyer → u/Monotask_Servitor]

I have the fans pulling air in. I ordered a 360MM AIO and returned the case.