NZXT H3 Flow (2025) Black Micro-ATX Airflow Mid-Tower PC Case with Tempered Glass, USB-C Gen 2x2 Front I/O, 280mm Front Radiator Support, Rear-Connect Ready (mATX) — CC-H31FB-01

The NZXT H3 Flow (2025) Black edition is designed for builders who want a stealthy, modern PC case that prioritizes airflow without sacrificing clean aesthetics or component compatibility. Built around the Micro-ATX form factor, the H3 Flow strikes an ideal balance between compact size and real-world performance potential, making it suitable for gaming systems, productivity workstations, and creator PCs alike. Its dark, minimal exterior pairs with a high-airflow internal layout to ensure your hardware stays cool, quiet, and visually refined.

The defining philosophy behind the H3 Flow series is simple: airflow matters. In compact systems especially, heat can accumulate quickly if airflow paths are restricted. The H3 Flow (2025) addresses this by supporting multiple intake and exhaust configurations, allowing builders to create a balanced cooling setup that maintains stable temperatures even during extended gaming sessions or heavy workloads. Whether you choose an air-cooled build or integrate liquid cooling, the internal layout is designed to keep air moving efficiently through the chassis.

Motherboard compatibility is focused and practical. The case supports both Micro-ATX and Mini-ITX motherboards, giving builders flexibility without increasing the overall footprint of the system. Importantly, it also supports rear/back-connect Micro-ATX motherboards, enabling cleaner cable routing by moving power and data connectors behind the motherboard tray. This feature is increasingly popular among builders who value a clean internal presentation, especially when paired with a tempered glass side panel.

The black version of the H3 Flow features a solid steel chassis finished in a deep matte black, paired with an ultra-clear tempered glass side panel. This combination gives the case a premium, understated appearance that works equally well in RGB-heavy builds or completely dark, non-RGB systems. The glass panel provides a clear view of your internal components without color distortion, making it ideal for showcasing high-quality hardware, neat cable management, or subtle lighting accents.

Despite its compact dimensions, the H3 Flow offers generous component clearance. CPU air coolers up to 170 mm in height are supported, allowing for the use of many high-performance tower coolers rather than forcing builders into low-profile solutions. GPU clearance is equally flexible. With no front fans installed, graphics cards up to 377 mm in length can be accommodated. When front fans are installed, clearance remains a very usable 352 mm, and even with a front radiator and fans installed, GPUs up to 317 mm can still fit comfortably. This level of transparency in clearance specifications helps builders plan their configurations confidently and avoid compatibility issues.

Cooling options are a core strength of the H3 Flow (2025). The front of the case supports radiators up to 280 mm, while the top supports radiators up to 240 mm, making it suitable for popular AIO liquid coolers. Fan mounting options are extensive for a Micro-ATX case: two fans at the front (120 mm or 140 mm), two at the top (120 mm or 140 mm), two at the bottom (120 mm), and one at the rear (120 mm). NZXT includes one rear 120 mm airflow fan pre-installed, providing immediate exhaust airflow right out of the box. This ensures the system is functional even before adding additional fans or radiators.

Front-to-back airflow is easy to configure, which is especially important for GPU cooling in compact builds. Builders can prioritize quiet operation with larger 140 mm fans, or focus on maximum cooling performance with higher-RPM 120 mm fans and radiators. The airflow-centric layout also helps reduce heat buildup around critical components like VRMs and memory modules, improving overall system stability.

Front I/O connectivity is modern and streamlined. The H3 Flow includes one USB 3.2 Type-A port for legacy compatibility and one USB-C 3.2 Gen 2x2 port for high-speed external storage and newer devices. This ensures the case remains relevant as USB-C peripherals become more common. Notably, the case does not include a front 3.5 mm audio jack, encouraging the use of rear motherboard audio, USB headsets, or external DACs for cleaner audio setups.

Storage support is designed for today’s SSD-focused builds while still allowing traditional drives where needed. The case supports multiple 2.5-inch drives and one 3.5-inch drive, making it easy to combine fast SSD storage with higher-capacity HDDs. Most builders will rely on NVMe SSDs installed directly on the motherboard, keeping the interior uncluttered and airflow unobstructed.

Power supply compatibility is equally flexible, with support for PSUs up to 185 mm in length. Cable routing space of up to 31.5 mm helps keep cables neatly tucked away, improving both airflow and visual cleanliness. Proper cable management is not just about aesthetics—it directly contributes to better cooling performance by reducing airflow resistance inside the case.

In summary, the NZXT H3 Flow (2025) Black is a refined Micro-ATX airflow case built for modern PC builders who want efficiency, compatibility, and a stealthy premium look. It delivers strong cooling potential, honest component clearances, and modern connectivity in a compact footprint, making it an excellent foundation for high-performance systems that look as good as they run.