Lian Li A4-H2O Review 2026: 11L Sandwich ITX Case for AIO Cooling

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Introduction

The Lian Li A4-H2O represents an ultra-compact ITX case specifically engineered and designed exclusively for AIO liquid cooling systems. This remarkably tiny 11-liter sandwich-style case represents extreme minimalism taken to its logical conclusion—literally every component serves a deliberate purpose, and there’s genuinely zero wasted internal space. The A4-H2O specifically appeals to hardcore enthusiast builders who genuinely appreciate compact elegance and actively welcome the specific challenge of constructing a high-performance build in deliberately constrained space. The innovative sandwich design with vertically-mounted motherboard orientation creates a visually distinctive aesthetic while simultaneously maximizing internal efficiency. If you genuinely want the smallest possible ITX case that still accommodates modern high-performance hardware with reliable liquid cooling capability, the Lian Li A4-H2O represents the ultimate expression of radical compact design philosophy.

1

Best Seller

Noctua NH-D15 G2 LBC, Quiet High-Performance Dual Tower CPU Cooler

Noctua

9.6 /10
ACMS Score

Updated: Aug 6, 2026
Last update on Aug 6, 2026 / Affiliate links / Product information sourced from Amazon.

$159.95

Dropped $5.00

View on Amazon.com

Specifications

Feature | Specification
Motherboard Support | Mini-ITX only
GPU Clearance | 320mm
CPU Cooler Max Height | Limited (AIO optimized)
Drive Bays | 1x 3.5″ + 2x 2.5″ bays
Included Fans | None
Dimensions | 345mm (H) x 230mm (W) x 375mm (D)
Weight | 2.8kg
Material | Aluminum frame, tempered glass
Radiator Support | Single 240mm AIO (top or front)
Front Panel I/O | USB 3.0 x1, 3.5mm audio jack

Build Quality & Design

Lian Li’s engineering excellence shines in the A4-H2O. The aluminum frame feels premium, tempered glass panels are crystal clear, and overall build quality is exceptional. At only 2.8kg, it’s the lightest case here while feeling robust. The sandwich design is intentional and elegant—components are visible from all angles. No wasted material, no unnecessary features, just pure minimalism. Cable routing requires care due to space constraints. Build quality is premium throughout, reflecting the A4-H2O’s positioning as a high-end compact case. The design feels timeless and architectural—more like art than a computer component.

Airflow & Thermal Performance

The A4-H2O’s thermal strategy relies entirely on AIO liquid cooling. There’s minimal passive airflow—the case is optimized for an AIO cooler mounted on top or front. Air cooling is impractical in this confined space. The sandwich design allows some component visibility to ambient air, but thermals depend on your AIO selection. With proper AIO cooling, thermal performance is excellent. GPU thermals rely on adequate case ventilation and quality GPU cooling. The design assumes you’re building with modern high-performance cooling solutions, not vintage air cooling.

Cable Management & Build Experience

Cable management in the A4-H2O is challenging but achievable. Space is extremely limited, requiring careful planning and high-quality modular PSUs. Every cable must route precisely. Build experience is contemplative—you’re actively thinking about placement and optimization. This isn’t a case for quick builds; it’s for builders who enjoy the challenge and appreciate compact design. Experienced ITX builders find it rewarding; newcomers may find it frustrating.

Compatibility

The A4-H2O supports Mini-ITX motherboards only. GPU clearance of 320mm accommodates most ITX graphics cards. CPU cooling must be an AIO—no air coolers fit. Drive bays are minimal with one 3.5″ and two 2.5″ slots. Single 240mm AIO mounting is the design focus. This case requires very specific component selection—you can’t just use any ITX components and expect them to fit.

RGB & Aesthetics

The A4-H2O’s aesthetic is minimalist elegance. Tempered glass panels on multiple sides showcase components beautifully. No integrated RGB—visual appeal comes entirely from your AIO cooler and components. The sandwich design creates a distinctive look that stands out compared to conventional cases. For builders wanting a unique, conversation-starting case, the A4-H2O delivers.

Pros & Cons

Pros

Ultra-compact 11-liter design for ultimate portability

Exceptional build quality and premium materials

Distinctive sandwich design that stands out

Lightweight (2.8kg) for easy transport

Showcases AIO cooling beautifully

Appeals to enthusiasts who appreciate extreme minimalism

Cons

Extremely tight space requires careful planning

No air cooling option—AIO mandatory

GPU clearance tight at 320mm

Limited drive bay options

Requires high-quality modular PSU

Not suitable for beginners or casual builders

Premium pricing for compact design

Comparison Table vs Competitors

Feature | Lian Li A4-H2O | Cooler Master NR200P | NZXT H7 Flow | Corsair 5000D Airflow
Volume | 11L (ultra-compact) | Compact | Standard | Large
Design Philosophy | Extreme minimalism | Budget compact | Practical minimalist | Performance airflow
Cooling Strategy | AIO mandatory | Air or AIO | Air or AIO | Air or AIO
Build Complexity | Extreme | Moderate | Low | Low
Weight | 2.8kg | 3.2kg | 4.8kg | 6.8kg
Price Range | Premium ($120-150) | Budget ($70-100) | Budget ($120-150) | Mid ($150-180)

Best Use Cases

Extreme Compact Enthusiasts: For builders who genuinely love challenging themselves with ultra-compact design constraints, the Lian Li A4-H2O represents the ultimate expression of compact innovation and minimalist engineering. It appeals to the specific builders who see tight spaces as design opportunities rather than limitations.

Showcase Builds: The distinctive sandwich design combined with top-mounted AIO visibility showcase potential make it genuinely perfect for show-quality compact builds designed to turn heads. Every component is visible and the overall presentation is genuinely unique.

Travel Gaming: At incredibly light 2.8kg with reasonable overall dimensions, it represents the most legitimately portable gaming case available for serious gamers who require regular portability. LAN party enthusiasts specifically appreciate the form factor.

High-End Compact: For builders specifically wanting premium materials and compact design philosophy without compromising on budget constraints or feature limitations. Premium builders appreciate the engineering.

FAQ

Can I use air cooling in the A4-H2O?

Not practically. The case is optimized for 240mm AIO cooling. Air coolers won’t fit due to space constraints.

What size AIO does it support?

Single 240mm AIO coolers mount on top or front. Larger coolers won’t fit.

Is this suitable for first-time builders?

No. The tight space and complex routing make it strictly for experienced ITX builders who enjoy technical challenges.

How much does it weigh?

Only 2.8kg—the lightest case here, making it highly portable for LAN events.

What GPU length can it accommodate?

GPU clearance is 320mm, limiting options to compact ITX graphics cards.

How much storage?

Minimal: one 3.5″ and two 2.5″ bays. Adequate for OS and a few games, not for large storage needs.

Final Verdict

The Lian Li A4-H2O is specifically designed for enthusiasts who genuinely view compact case design as a legitimate art form deserving respect. This emphatically isn’t a practical, pragmatic case for mainstream audiences—it’s intentionally a premium statement piece for builders who genuinely appreciate extreme minimalism and willingly accept the technical challenges it presents. Build quality throughout remains truly exceptional, the distinctive sandwich aesthetic stands out genuinely unique, and overall mechanical engineering proves outstanding. Cable management demands considerable care and planning, component selection options are necessarily limited, and the actual building experience requires patience and technical knowledge. But for enthusiasts who genuinely love compact design challenges, AIO cooling systems, and aren’t afraid of working in tight spaces, the A4-H2O delivers genuinely rewarding results. Not recommended for casual first-time builders or beginners seeking simplicity, but genuinely essential for hardcore compact enthusiasts willing to embrace the challenge. Before committing, carefully check our comprehensive motherboard form factor guide to fully understand Mini-ITX compatibility constraints and requirements.

1

Best Seller

Noctua NH-U12A chromax.Black, Quiet High-Performance Tower CPU Cooler

Noctua

9.8 /10
ACMS Score

Updated: Aug 6, 2026
Last update on Aug 6, 2026 / Affiliate links / Product information sourced from Amazon.

$119.95

Dropped $5.00

View on Amazon.com

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Frequently Asked Questions

What size components does an 11 litre case require?

An ITX motherboard, an SFX or SFX-L power supply and a graphics card within the stated length and slot limits. Tower air cooling is largely off the table for the CPU, which is why the design targets a 240mm all-in-one liquid cooler in the side bracket.

How large a graphics card fits?

The sandwich layout allows a surprising amount of card length, generally in the 320mm range, but slot thickness is the harder constraint because the GPU chamber depth is fixed. Check your card’s thickness in slots, not just its length, before committing to this chassis.

Do I need a riser cable and is it included?

Yes, a PCIe riser is essential to the sandwich layout and Lian Li includes one. Confirm it is rated for the PCIe generation your board and card use, since an older riser on a newer platform can cause instability that only appears under load.

Will it run hot?

It runs warmer than a mid-tower, unavoidably, because both chambers are shallow and the components sit close together. With a 240mm all-in-one on the CPU and unobstructed side ventilation for the graphics card it stays within safe limits, though fan noise under load is higher.

Is this a good first build?

Not really. Small form factor builds demand careful part selection, cable routing planning and patience with assembly order. If this is your first PC, a compact ATX case gives most of the space saving with a fraction of the frustration and cheaper component options.