Lian Li A4-H2O Small Case - Mini ITX - Aluminum Exterior & SPCC Steel Interior - PCIe 4.0 - Easy AIO Installation - Supports SFX/SFX-L Power Supply (A4-H2O A4 BLACK)

I’ve been shopping around for a good ITX case for months and have been having a serious problem finding something that can fit a large enough cooler to allow my 9700x to stay cool while encoding at 100% usage. This case finally did it with a liquid cooler master atmos 240aio. Even with overclocking im not getting CPU temps above 75°C! on other cases with air coolers they were becoming heat soaked and reaching temps upwards of 95°C. I also fit a full SF750L PSU in this thing that’s way better than the low efficiency unreliable mini itx flex PSU. Lian Li did a great job with this case. So many cards are applicable with it and it’s small enough to carry in a pelican case. It’s not what I was originally going for with my build but ended up being necessary with the amount of load I run through my PC. The hardest part was routing the AIO cooler lines. I definitely would recommend for the price!

TL;DRI really like it. It's small, and still has more space than I thought. Easy to build in, even as a first-timer. Very much recommend it. The one I received was missing the PCIe riser cable and the power switch cable, but that may have been a reseller issue, not a manufacturing one.Components I Used:AMD Ryzen 7 7700 CPUROG Strix B650Ei Gaming Wi-Fi MotherboardRipjaws S5 DDR5-6000 32GB RAM (x2)WD_Black SN770 1TB NVMe SSD Drives (x2)ASUS Dual Radeon RX 6600 GPUCorsair H100i Hydro-Cooling FanCorsair SF750 Power SupplyCooler Master PCIe 4.0 x16 riser cable*The PositivesI love the design and model. It's even smaller than I expected, but it still holds a lot more space. For a case that's the size of a shoebox, the internal layout makes it easy to work with if you have the right parts. I still have room left over to add SATA SSD drives, or maybe even drop in a small figurine for fun.The ventilation is exceptional. There are vents on almost every side, and the panels are easy to pop off when needed, which helps with airflow and access. I have decent cooling components, and since this is a development machine and not a gaming rig, the system has stayed cool to the touch since I started using it.The case is very straightforward to work with. This was my first PC build, and the process went smoothly. I’d recommend this to anyone who wants a clean, sleek, utilitarian setup.The NegativesMy unit was missing several components that were supposed to be included. There was no screw bag, and some of the screws for the top and bottom inner panels were missing. Most importantly, the PCIe riser cable wasn’t included, even though it’s shown in both the manual and the product listing. I had to buy a replacement for $40, though I did receive a partial refund.The power switch cable for the case's power button was also missing. Only a reset switch cable was included, so I had to short the power pins on the motherboard with a screwdriver to turn the system on. That's pretty bad. I eventually repurposed the reset switch cable to act as the power switch. It works, but that’s clearly a hack and not how it was intended to be used.

Love the aesthetics and form factor of this case! Ample space for a mATX build, and the perforated exterior allows for great airflow. Just note that you will need to purchase your own case fans.

Pros and Cons AnalysisProsCompact Yet Versatile Size (26.3L)At 26.3 liters, the A3-mATX strikes a balance between small form factor and compatibility with high-end components like 415mm GPUs and 165mm CPU coolers. It’s snug but workable for powerful builds.Excellent Airflow PotentialThe mesh top and side panels, combined with support for up to 10x 120mm fans, provide robust airflow. My experience with the Noctua NH-D15 and a single fan setup still yielded "tons of airflow," especially with an exhaust and side fan, highlighting its ventilation strengths.High Case QualityLian Li’s reputation shines through with solid steel construction and a premium feel, despite the budget price. The mesh panels are sturdy, and even the plastic front panel (or wood trim option) feels well-crafted for $90-$100.Flexible Cooling OptionsSupports up to a 360mm AIO on top or 280mm on the side, plus large air coolers like the NH-D15 (up to 165mm). Your switch to the DH-15 worked well, retaining an exhaust fan, which shows adaptability even if not ideal for your Z63.Modern I/OThe front panel includes a fast USB-C (10Gbps), two USB-A ports, and separate audio jacks, making it future-proof and convenient.Ease of Assembly (With Planning)The tool-less side and front panel removal, along with a removable side fan bracket, simplifies assembly. My DH-15 setup, while snug, was manageable, suggesting that with careful component selection, it’s straightforward.ConsLimited AIO Mounting FlexibilityMy NZXT Z63 couldn’t mount on top (likely due to clearance or radiator thickness constraints), forcing a side mount where the screen isn’t visible. Losing the rear exhaust fan in this setup is a notable drawback, reducing exhaust options and potentially impacting thermals.Cramped Interior SpaceW/ only 26.3L (yes, I wanted something more compact than Lian Li O11 mini), fitting large components like the NH-D15 (even with one fan) or a 360mm AIO can feel restrictive. Cable management is also challenging due to minimal space behind the motherboard tray.Compromised Fan ConfigurationsUsing the NH-D15 with one fan (due to space limits) and the Z63 side mount sacrificing the rear exhaust highlight how fan placement can be a trade-off. The case supports many fans, but not always in ideal harmony with larger coolers.Ease of Installation Hampered by ConstraintsInstallation isn’t as seamless as larger cases. My Z63 experience required rethinking mounting, and the DH-15’s single-fan setup suggests extra effort to optimize. The flexible PSU bracket helps, but planning is critical to avoid clearance issues.No Included FansUnlike some competitors, the A3 comes with no pre-installed fans, adding cost and setup time. You had to rely on your cooler’s fans or add your own for exhaust and side intake.Cable Management StrugglesThe tight space and lack of dedicated cable routing options make tidying cables difficult, especially with bulkier ATX PSUs or AIO tubing, which could detract from the build experience.My Rating: 3.6/5 Explained3.6 rating aligns with the case’s strengths and quirks. The inability to top-mount your NZXT Z63 AIO (likely due to radiator thickness exceeding the 52mm limit with fans or VRM interference) and the obscured screen on the side mount are valid frustrations. Losing the rear exhaust fan with the Z63 further limits airflow options, which clashes with my cooling preferences. Switching to the Noctua NH-D15 mitigated some issues—restoring an exhaust fan and adding a side fan—but the snug fit and single-fan limitation (due to clearance) underscore the case’s spatial trade-offs. For the "tons of airflow" with the DH-15 setup is a win, but the compromises in mounting flexibility and ease of installation drag the score down from a potential 4 or higher.Additional Notes on Ease of Installation, Case Quality, and Ease of AssemblyEase of Installation: Moderately easy with simpler setups (e.g., air cooling like the DH-15), but trickier with AIOs like the Z63 due to clearance and fan trade-offs. Requires pre-planning for PSU and cooler placement.Case Quality: Top-notch for the price—steel mesh panels feel durable, and the minimalist design is sleek. No major quality control issues reported widely, unlike some reviews noting minor fitment quirks.Ease of Assembly: Straightforward with removable panels and brackets, but the snug interior demands patience and precision, especially with cable management or larger components.The Lian Li A3-mATX is a solid choice for compact, airflow-focused builds, but your experience shows it’s not perfect for every cooling setup without some compromises.