If you are constantly struggling with stringing, crackling, weak layers, or failed prints caused by damp filament, a dedicated filament dryer is one of the smartest upgrades you can make. SUNLU has established itself as a leading brand for affordable, high-performance drying solutions. The current model lineup – FilaDryer S2, S4, and E2 – covers every user: from the casual hobbyist to the professional workshop.
In this detailed comparison, we will cover technical specifications, practical performance, pros and cons, and concrete purchasing recommendations – to help you find the perfect SUNLU dryer for your needs.
Why every 3D printer owner needs a filament dryer
Most common filaments (especially hygroscopic ones like Nylon, PETG, TPU, as well as technical variants like PA-CF or PC) absorb moisture from the air within just a few hours. Damp filament leads to:
- Bubbles and steam in the nozzle
- Poor layer adhesion and brittle parts
- Clogs and uneven extrusion
- Surface defects and stringing
A good dryer removes moisture before (and during) printing, vastly improving print quality and success rates. The SUNLU models shine with fast heating, precise control, quiet operation, and the ability to print directly while drying (via PTFE tube ports).
Brief overview of the SUNLU models
| Feature | S2 (Compact) | S4 (Multi-Spool) | E2 (Engineering Pro) |
|---|---|---|---|
| Capacity | 1 spool (typically 1 kg) | 4 × 1 kg spools | 2 × 1 kg / 2 × 2 kg / 1 × 3 kg |
| Max. Temperature | 70 °C | 70 °C | 110 °C |
| Power | 48 W | 320–350 W | 500 W |
| Heating Tech | 360° convection + fan | PTC + 3 convection fans | PTC + dual chamber |
| Display | 4.6-inch touchscreen | Touchscreen | Touchscreen + humidity display |
| Best for | Beginners & single users | Workshops & multi-color | Technical filaments + annealing |
| Approx. Price | €45–€80 | €140–€160 | €300–€360 |
| Dimensions (mm) | 265 × 274 × 118 | 458 × 218 × 312 | 400 × 220 × 307 |
| Weight | 1.19 kg | 4.8–5.5 kg | 6.1 kg |
SUNLU FilaDryer S2 – The best compact & affordable entry-level option
The S2 is SUNLU's most popular entry-level dryer and a huge leap in quality over simple storage boxes.
Key features:
- Holds one standard 1 kg spool (max. Ø 210 × 85 mm)
- Temperature range 35–70 °C with one-key presets for PLA, PETG, ABS, etc.
- Intuitive 4.6-inch touchscreen (temperature, timer, filament type, LED control)
- 360° convection heating + fan for even drying
- Very quiet (<10 dB)
- Printing while drying possible (PTFE tube outlet)
- Tiny footprint – perfect next to the printer or on a desk
Pros:
- Extremely affordable and portable
- Very even heating for its size
- Super simple operation via one-touch
- Ideal for drying during long print jobs
Cons:
- Only one spool at a time
- Not suitable for high-temperature technical filaments
Who is the S2 ideal for? Beginners, students, or users with a single printer and limited space. If you mainly print PLA and PETG and want big improvements on a budget, the S2 is the clear choice.
SUNLU FilaDryer S4 – The best for multi-color and workshop use
Need multiple filaments dry and ready for use at the same time? The S4 is SUNLU's flagship for multi-spool drying.
Key features:
- Huge internal chamber (450 × 210 × 211 mm) – room for 4 × 1 kg spools simultaneously
- 320–350 W PTC heating + three convection fans for ±3 °C temperature accuracy
- Fast heating: 50 °C in ~30 min, 70 °C in ~50 min
- 8 filament outlets (top + side) – can supply up to 4 printers simultaneously
- Touchscreen with humidity display and automatic mode
- Triple safety protection (PTC, thermal switch, software)
Pros:
- Unbeatable capacity and price-to-performance for multi-spool drying
- Even heat distribution across all spools
- Perfect as a dryer and for long-term storage
- Ideal for multi-color setups (e.g., AMS-style)
Cons:
- Larger footprint and higher power consumption
- Max. temperature limited to 70 °C
Who is the S4 ideal for? Makers with multiple printers, multi-color projects, or small workshops who want to keep various filaments (PLA, PETG, ABS, TPU) constantly ready. It is the sweet spot for ambitious hobbyists and small businesses.
SUNLU FilaDryer E2 – The best for technical filaments & annealing
The latest and most advanced model – the E2 was developed specifically for demanding materials.
Key features:
- Holds 2 × 1 kg, 2 × 2 kg, or 1 × 3 kg spools (max. Ø 250 × 153 mm)
- 35–110 °C range – the highest rating from SUNLU
- 500 W PTC heating – 70 °C in ~30 min, reaches maximum temperature very quickly
- Genuine 2-in-1 dryer + annealer (dedicated annealing mode + pull-out drawer)
- Dual-chamber design with excellent insulation (outer skin stays <60 °C at 110 °C inside)
- Humidity display, advanced safety alarms, and continuous silicone seal
- Preset modes for PA6-CF, PA12-CF, PC, PPS, etc.
Pros:
- Handles practically any technical filament (Nylon, carbon fiber, polycarbonate)
- Annealing function massively increases part strength and heat resistance
- Outstanding build quality and insulation
- Future-proof for demanding materials
Cons:
- Highest price point
- Larger and heavier than S2/S4
Who is the E2 ideal for? Professional users, functional part printers, or anyone working with Nylon, PC, or CF-filled filaments, or wanting to anneal parts. Anyone needing 110 °C or looking for annealing features will find nothing comparable in this price range.
Direct comparison & purchase recommendation
Choose the SUNLU S2 if:
- You have a single printer and mainly print standard filaments
- Your budget is under €100
- You value small size and very quiet operation
Choose the SUNLU S4 if:
- You operate 2+ printers or do multi-color projects
- You want maximum capacity at the best price
- You do not need temperatures above 70 °C
Choose the SUNLU E2 if:
- You print technical filaments (Nylon, PC, CF, etc.)
- You want to anneal parts to achieve maximum mechanical properties
- You want to invest in premium performance
Pro-tip: Many users combine models – an S2 right next to the printer for daily use + an S4 or E2 for bulk drying and storage.
Conclusion
SUNLU has perfectly covered the filament dryer market with three excellent, targeted models:
- S2 = Best entry-level / everyday dryer
- S4 = Best all-rounder for most makers
- E2 = Best premium choice for serious engineering
All three offer printing while drying, reliable safety features, and huge improvements in print quality. No matter which model you choose – you will wonder how you ever printed without a dryer.
Ready to keep your filament perfectly dry? Check out the current prices and bundles in the official SUNLU store (there are often flash sales and filament bundles that make the price-to-performance ratio even better).
Wondering which model fits your setup? Write a comment with your printer type and the filaments you use – I'm happy to help you decide!
Frequently Asked Questions (FAQ)
Can you print directly from the dryers? Yes – all models support PTFE tube pass-throughs for active drying during printing.
Do they work with the Bambu Lab AMS? Absolutely. Many users successfully combine the S4 or E2 with AMS / AMS HT.
How long should you dry filament? Usually 4–12 hours, depending on material and moisture level. Nylon often needs 8–24+ hours at higher temperatures.
Are they noisy? The S2 is almost inaudible (<10 dB). S4 and E2 have fans, but remain quiet enough for a desk.
Do I need the E2 if I only print PLA? No – the S2 or S4 is perfectly sufficient (and cheaper).
Happy printing – and may your spools remain dry forever! 🖨️
