NZXT is an American manufacturer of computer components and supplier of complete systems. The company was founded in Los Angeles in 2004. The portfolio, which initially only included computer cases, now also includes cooling components, PC accessories, monitors and streaming accessories. In 2017, a service for building complete systems was added under the name BLD. Today, in this review, we take a closer look at the new NZXT H3 Flow, which completes the H series as a mini tower and was launched in May 2025.
Technical details
| Model: | NZXT H3 Flow Test |
| Case type: | Mini-Tower |
| Dimensions: | 225 mm (W) x 400 mm (H) x 389 mm (D) |
| Weight: | 4.8 kg |
| Material: | Steel, plastic, tempered glass |
| Color: | Black |
| Front connections: | 1x USB 3.1 Type-C, 1x USB 3.0 Type-A, |
| Drive bays: | 1x 3.5″ or 2x 2.5″ 1x 2,5″ |
| Expansion slots: | 4x horizontal |
| Form factors: | µATX, ITX |
| Ventilation: | Front: 2x 120/ 140 mm Rear: 1x 120 mm Top: 2x 120 / 2x 140 mm PSU cover: 2x 120 mm |
| Radiators: | Front: 1x 240/ 280 mm Rear: 1x 120 mm Lid: 1x 240/ 280 mm |
| Max. CPU cooler height: | 170 mm |
| Max. Graphics card length: | 377 mm (without front fan), 352 mm (with front fan) |
| Max. Power supply length: | 300 mm (without HDD), 200 mm (with HDD) |
| Space for cable management: | approx. 30 mm |
| Price: | € 77.99 * |
| Special features: | Cable management, tempered glass |
NZXT H3 Flow Test: The scope of delivery
NZXT packs the H3 Flow in a simple brown cardboard box. On the front, the manufacturer prints a picture of the mini-tower on the packaging and adds a colored sticker showing the color variant of the case inside. A technical drawing and a table with all the technical data can also be seen on the side.
Inside, NZXT wraps the H3 Flow in two thick blocks of normal polystyrene and a plastic film. As the case only weighs around five kilograms, these protective measures should be more than sufficient. NZXT places the mounting accessories in a small box, which is attached to the inside of the mini-tower with a wire. It contains numerous cable ties, all the necessary mounting screws and illustrated assembly instructions. All screws are individually packaged and labeled.
Exterior impression
Visually, the H3 Flow follows the design of its larger brothers, the H5 Flow and H7 Flow. The exterior design of the mini tower is extremely straightforward and simple. The front panel is made of steel and has a fine ventilation grille, which also serves as a dust filter. A mounting system with push pins is used to attach it to the body. This means that the panel can be removed with a gentle tug. Behind it, mounting slots for two 120 mm or 140 mm fans or a corresponding radiator are then revealed.
The lid section is characterized by an open mounting frame for two 120 mm or 140 mm fans or a correspondingly large radiator. NZXT has placed a magnetic mesh filter above the opening to protect against dust and to achieve a uniform overall appearance. The I/O panel, which can also be found in the lid, only consists of the bare essentials. There is a white illuminated power button, a USB-C port and a USB-A port.
As with the H5 Flow (2024), the left side of the case has a very interesting design. In addition to a slightly tinted side panel made of tempered glass, which is also connected to the body via push pins, we find a fine mesh grille in the lower area, which is rounded towards the bottom. The right side panel is made of steel, is attached with knurled screws and also has a ventilation opening. NZXT has not implemented additional dust filters on either side.
The rear of the NZXT H3 Flow holds no surprises and corresponds to the current standard. The power supply unit is mounted at the bottom of the case and four reusable and perforated slot covers can be seen above it. In the upper area, NZXT installs the only pre-installed fan in the H3 Flow with a frame width of 120 millimeters.
We were surprised by the underside of the NZXT H3 Flow. Contrary to expectations, there is almost nothing to see here. There is neither a ventilation opening for the power supply unit nor proper case feet. However, sufficiently thick rubber surfaces have been glued to the underside to protect the surface. Finally, we find screw holes in the front area of the underside for mounting data carriers inside.
Interior impression
The interior of the NZXT H3 Flow is similarly simple and divided into two chambers of different sizes. The large main chamber offers space for a µATX mainboard, a large CPU cooler or a long graphics card and even two radiators. Numerous cable management openings and holes for mainboards with rear connections have also been cut into the mainboard tray. Finally, the power supply cover in the base has ventilation openings and mounting points for two optional 120 mm fans.
There are no disruptive hard disk cages or other elements behind the optional front fans that could interfere with the airflow. The heated air can flow freely through the interior and is then actively conveyed to the outside by the pre-installed rear fan or can escape passively via the various ventilation openings.
The rear of the NZXT H3 Flow also remains unspectacular. The motherboard tray is flat and the manufacturer has provided plenty of eyelets for cable ties. NZXT has also added practical cable guides around the cut-out for the CPU cooler backplate. These are particularly useful for simply moving cables “out of the way”. In the lower area, you can see the empty power supply compartment. The power supply unit rests on two rubber strips, but can only be installed with the fan facing upwards due to the lack of openings in the base.
The NZXT H3 Flow does not offer much space for data carriers. A 3.5″ HDD or alternatively two 2.5″ SSDs can be placed in the base. There is also a mounting option for a 2.5″ SSD behind the mainboard tray. In either case, the installation is not decoupled and requires the use of tools. The SSD behind the mainboard tray can also only be screwed on if the power supply unit is not yet installed.
Processing
Overall, the workmanship of the NZXT H3 Flow can be described as good. All components and elements have been processed properly and we could not find any paint defects, sharp edges, scratches or dents. The push-pin mechanisms also work perfectly and attaching the side panels did not lead to any moments of frustration. However, we did not find the thickness of the material in some places, such as the right-hand side panel, to be so positive.
NZXT H3 Flow test: Installing the components
Now we come to the system installation in the NZXT H3 Flow test. As hardware, we use an AMD Ryzen 5 1400* on an ASUS TUF Gaming B550M-Plus* with 16GB Crucial Ballistix Sport LT gray DDR4-2666*. The Ryzen is cooled by an Alpenföhn Brocken 4* and is overclocked to 3.8 GHz (1.175 V). A Gigabyte AORUS GTX 1060 6GB is responsible for the image output. The power supply is provided by the fully modular LC-Power LC550 V2.31 Platinum*.
The installation of the test system in the NZXT H3 Flow went without any problems and was completed quickly. There is enough space to work in most places and all cable management openings were sensibly positioned. The additional cable covers and eyelets for cable ties also help to keep the system neatly wired. The correctly pre-installed spacers, including a pin that holds the mainboard in place even when not screwed in, also save time.
Although the NZXT H3 Flow is quite compact, it offers plenty of space for hardware inside. CPU coolers can be 170 millimeters high and graphics cards up to 377 millimeters long. However, the latter only applies if no fan is installed in the front. If no hard disks are installed in the base, the power supply unit may be up to 300 millimetres long. However, it should not exceed a length of 200 millimeters with data carriers. With regard to water cooling, a 240 mm or 280 mm radiator can be accommodated in both the lid and the front.
NZXT installs a single 120 mm fan ex works. This fan is of the NZXT F120 type and has a very simple design. It consists of a black frame and a black rotor. Decoupling and the use of PWM are also dispensed with. Instead, it is supplied with power via a conventional 3-pin 12V connection. The speed range of the fan in our example is between 540 and 1420 revolutions per minute.
Load test
Finally, we come to the temperatures that were reached in the NZXT H3 Flow test. During the stress test, Prime95 and FurMark were run at a room temperature of 20 °C for 30 minutes. In addition, the stress test was carried out in the standard fan configuration with three speeds (minimum speed, 7V, 12V). The results are listed in the table below.
Scenario |
Temperature |
| CPU: 50% PWM (1220 rpm) GPU: 50% PWM (1650 rpm) Benchtable/ open setup |
CPU: 65.4 °C GPU: 62.8 °C |
| CPU: 50% PWM (1220 rpm) GPU: 50% PWM (1650 rpm) Rear: 1x 120 mm minimum speed (540 rpm) |
CPU: 68.4 °C GPU: 66.5 °C |
| CPU: 50% PWM (1220 rpm) GPU: 50% PWM (1650 rpm) Rear: 1x 120 mm 7V (860 rpm) |
CPU: 66.7 °C GPU: 64.3 °C |
| CPU: 50% PWM (1220 rpm) GPU: 50% PWM (1650 rpm) Rear: 1x 120 mm 12v (1420 rpm) |
CPU: 64.2 °C GPU: 61.9 °C |
We would describe the cooling performance of the NZXT H3 Flow as very good in its factory settings. The temperature differences between minimum and maximum speed are significantly lower compared to other cases. It should also be mentioned that our test system is far away from critical temperatures even in the worst-case scenario. However, if you are planning a system with more powerful components, you should definitely install one or better still two fans in the front. The pre-installed fan is slightly audible from around 800 revolutions per minute and clearly audible to annoying at more than 1200 revolutions. Unfortunately, slight background noises are also constantly audible.
NZXT H3 Flow test: Conclusion
We have now reached the end of this test. With the NZXT H3 Flow, the manufacturer completes the H series with the first mini tower, which has already been eagerly awaited by some. Overall, however, we have somewhat mixed feelings about the H3 Flow. The H3 Flow has a simple look, which has been given an interesting design accent by the design of the left side of the case. In addition, despite its compact design, it offers plenty of space for hardware inside and there are also cut-outs for mainboards with rear connections. The workmanship of the H3 Flow is mostly good.
On the other hand, we noticed the small number of mounting slots for data carriers and the fact that the power supply unit can only be mounted with the fan facing upwards. Despite side ventilation openings in the lower area, there is a very high probability that the power supply and GPU will have to fight for fresh air with large graphics cards. Added to this is the extremely minimalist I/O panel and the somewhat thin material thickness in places.
Overall, we feel that the current price of € 77.99 * is too high for the overall package on offer. Especially when you consider that the better-equipped H5 Flow 2024 costs almost as much. Of course, mini-towers are “sneezier” than midi-towers, but for the NZXT H3 Flow to be fully competitive, the price would have to come down a bit.
- Simple design
- Good airflow/ good cooling
- Compact dimensions
- Plenty of space for hardware
- Preparation for motherboards with rear connectors
- Good cable management system
- Minimalist I/O panel
- Power supply unit can only be mounted with fan facing upwards
- Material quite thin in places
- Little space for data carriers
NZXT H3 Flow
Processing
Structure
Equipment
Cooling
Price-performance ratio
84/100
The NZXT H3 Flow is a simple and compact mini tower that still offers plenty of space for hardware and good airflow. For the overall package on offer, however, we feel that the RRP is a little too high.
