Best Filament Dryers in 2026: Sunlu, eSUN, Sovol Compared

Moisture is the silent killer of 3D print quality. You can have the perfect slicer settings, a calibrated printer, and premium filament — but if that filament has absorbed moisture from the air, your prints will pop, string, and look terrible. I learned this the hard way after blaming my printer for issues that were actually caused by wet filament. A filament dryer solved the problem completely.

I have tested three popular filament dryers head-to-head to find which one actually removes moisture effectively and which ones are just fancy filament holders with a heater.

Why Filament Drying Matters

All 3D printing filaments are hygroscopic to some degree — they absorb moisture from the air. Some materials are worse than others:

• Nylon: Absorbs moisture aggressively. Unusable without drying in humid environments.
• PETG: Noticeable quality degradation within days of exposure.
• TPU: Absorbs moisture quickly, causing bubbles and rough surfaces.
• PLA: Absorbs slowly but still affected over weeks.
• ABS: Moderate absorption, affects surface quality.

The symptoms of wet filament include popping or crackling sounds during extrusion, rough surface texture with small bubbles, excessive stringing, poor layer adhesion, and inconsistent extrusion width. If you hear your filament hissing as it goes through the hot end, it is wet.

According to CNC Kitchen's filament moisture testing, even PLA left in ambient conditions for two weeks in a humid environment shows measurable degradation in print quality and mechanical properties.

How Filament Dryers Work

A filament dryer is essentially a low-temperature oven designed for filament spools. It heats the filament to a specific temperature (below the glass transition temperature so the spool does not deform) for several hours. The heat drives moisture out of the filament as water vapor, which escapes through vents.

Most dryers include a hygrometer to show the humidity level inside the chamber. As the filament dries, you will see the humidity reading drop from ambient levels (often 40-60%) down to 10-20% or lower.

The key parameters are temperature accuracy (needs to hit the right temp for each material), temperature uniformity (the entire spool needs even heating), air circulation (helps distribute heat and remove moisture), and sealing (prevents ambient moisture from re-entering during drying).

Sunlu S2 Filament Dryer — Best Overall

The Sunlu S2 has become the default recommendation in the 3D printing community, and after extensive testing, I agree it earns that position. It combines effective drying, a practical design, and a reasonable price.

Temperature range: 35-70°C in 5°C increments. Covers all common filaments.

Temperature accuracy: Measured with an external thermocouple, the S2 maintained temperature within ±2°C of the set point after reaching steady state. At the 50°C setting (for PLA), I measured 48-52°C across different spots in the chamber. At 65°C (for PETG), I measured 63-67°C. This is good accuracy for a consumer device.

Drying effectiveness: Starting from ambient conditions (22°C, 50% humidity), I placed a roll of PETG that had been left open for a week. The internal hygrometer showed:

• Start: 52% humidity
• 2 hours: 28% humidity
• 4 hours: 15% humidity
• 6 hours: 11% humidity

After 4-6 hours, the PETG printed cleanly with no popping sounds or surface defects. I consider 4 hours at 65°C the minimum for wet PETG.

Feed-through design: The S2 has filament feed holes that let you run filament directly from the dryer to your printer while drying. This is hugely practical for long prints in humid environments — the filament stays dry throughout the entire print. I use this feature constantly with PETG and nylon.

Spool compatibility: Holds standard 1kg spools up to 2.5kg. The internal diameter accommodates most spool hub sizes. Larger 3kg spools will not fit.

Build quality: Solid plastic construction with a clear top for monitoring. The touchscreen display is responsive and easy to read. Timer function lets you set drying duration up to 24 hours.

Price: ~$45.

Verdict: The Sunlu S2 does what it promises, reliably, at a fair price. It is my primary recommendation for anyone who prints with moisture-sensitive filaments. Rating: 9/10.

eSUN eBox Lite — Best for Active Printing

The eSUN eBox Lite takes a slightly different approach — it is designed primarily as an active drying/feeding station rather than a passive dryer. The design emphasizes feeding filament directly to your printer from the heated chamber.

Temperature range: 40-55°C. More limited than the Sunlu S2, which means it cannot reach the temperatures needed for nylon (60°C+) or polycarbonate.

Temperature accuracy: Within ±3°C of set point. Slightly less accurate than the S2 but still functional.

Drying effectiveness: At 55°C with PLA, internal humidity dropped from 48% to 18% in 4 hours. Good but not as fast as the Sunlu at its higher temperature settings. For PETG, the 55°C maximum works but takes longer than the ideal 65°C.

Feed-through design: The eSUN excels here. The filament path through the dryer is well-designed with a smooth feed hole and optional PTFE guide. It also includes a built-in filament weight scale that shows how much filament remains on the spool. This is a genuinely useful feature that no other dryer offers.

Build quality: Good. The design is compact and the display is clear. The weighing function is accurate to within a few grams.

Price: ~$50.

Verdict: A good dryer with the unique filament weighing feature, but the limited temperature range is a meaningful drawback for materials like nylon. Best for users who primarily print PLA and PETG. Rating: 7.5/10.

Sovol SH01 Filament Dryer — Best Temperature Range

The Sovol SH01 pushes the temperature range higher than most consumer dryers, making it suitable for engineering materials that need more aggressive drying.

Temperature range: 35-75°C. The highest I have seen on a consumer filament dryer. The 75°C setting is appropriate for nylon and polycarbonate drying.

Temperature accuracy: Within ±2°C. Good accuracy, comparable to the Sunlu S2.

Drying effectiveness: At 65°C with a wet roll of nylon, humidity dropped from 55% to 12% in 6 hours. At 75°C, the same starting conditions reached 10% in 4.5 hours. The higher temperature genuinely accelerates drying for materials that can handle it.

Design notes: The SH01 holds standard 1kg spools and has feed-through holes for active printing. The construction is solid with a visible internal fan for air circulation, which helps with temperature uniformity.

Hygrometer accuracy: I compared the built-in hygrometer against a calibrated external sensor. The SH01's reading was about 4% higher than the external sensor, which is within acceptable tolerance for a built-in unit. All consumer dryer hygrometers should be treated as approximate.

Price: ~$55.

Verdict: The best choice for users who print engineering materials (nylon, PC, ABS) that need higher drying temperatures. For PLA/PETG-only users, the Sunlu S2 is sufficient and costs less. Rating: 8/10.

Budget Alternative: DIY Food Dehydrator

Before dedicated filament dryers existed, the community used food dehydrators. A basic food dehydrator with adjustable temperature can dry filament effectively at a lower cost.

Advantages: Cheaper ($30-35), can accommodate multiple spools if you remove some trays, and provides good air circulation.

Disadvantages: Not designed for filament — some spools do not fit without modification. No feed-through for active printing. Temperature control is less precise. Looks out of place on a 3D printing desk.

I used a dehydrator for my first year of printing and it worked fine. But after switching to a dedicated dryer with feed-through, I would not go back. The convenience of drying while printing is worth the extra cost.

Drying Temperatures by Material

These are the temperatures I use based on my testing and manufacturer recommendations:

| Material | Drying Temperature | Minimum Time | Notes | |----------|--------------------|--------------|-------| | PLA | 45-50°C | 4 hours | Do not exceed 55°C — PLA softens | | PETG | 60-65°C | 4-6 hours | Standard drying | | TPU | 50-55°C | 4-5 hours | Gentler than PETG | | ABS | 65-70°C | 4-6 hours | Can handle higher temps | | ASA | 65-70°C | 4-6 hours | Same as ABS | | Nylon | 70-75°C | 6-8 hours | Very hygroscopic, needs aggressive drying | | PC | 70-80°C | 6-8 hours | Most dryers max at 75°C |

The 3DXTech drying guide provides detailed recommendations that align with my testing.

Storage After Drying

Drying is only half the battle. If you dry your filament and then leave it exposed, it will reabsorb moisture within hours in humid environments. Proper storage is essential:

Vacuum bags with desiccant — Vacuum seal bags with silica gel packs provide the best long-term storage. Seal the filament immediately after drying.

Airtight containers — Large plastic bins with rubber gasket lids work well for filament in active rotation. Add desiccant packs and a hygrometer to monitor humidity.

Print directly from the dryer — For the most moisture-sensitive materials, feed filament from the dryer directly to your printer during the entire print. This is the approach I use for all nylon and most PETG printing.

Which Dryer Should You Buy?

Sunlu S2 — For most users. Good temperature range, reliable performance, feed-through design, reasonable price. This covers PLA through ABS/ASA effectively.

Sovol SH01 — For engineering material users. The 75°C max temperature handles nylon and PC drying. Worth the premium if these materials are part of your workflow.

eSUN eBox Lite — For the filament weight monitoring feature. If knowing exactly how much filament remains on a spool matters to you, the built-in scale is unique and useful.

Final Thoughts

A filament dryer is not a luxury accessory — it is essential equipment for anyone who prints with PETG, TPU, nylon, or any hygroscopic material. Even PLA benefits from drying if you live in a humid climate. The investment pays for itself in reduced print failures and improved quality.

Pair your dryer with proper storage, and check 3DSearch for AI slicer settings that account for your filament's material properties. Dry filament combined with optimized settings produces the best possible print quality.

Happy printing!