SUNLU S1 Plus vs S2: which dryer is the smarter buy for your filament?

Display / Screen quality

Winner: Product B (S2)

Neither of these dryers is about flashy UI, but the S2 has the more modern, more capable spec on paper thanks to its 360° all-round heating system and 70°C max temperature. That matters more than a fancy screen in a filament dryer, because the whole point is consistent drying rather than looking nice on the desk. The S1 Plus is simpler and easier to live with if you just want a basic, portable box, but the S2’s heating approach is the more advanced design and gives it the edge for users who care about control and results.

Performance

Winner: Product B (S2)

This is the big one. The S2 is explicitly built around 360° all-round heating and a 70°C maximum temperature, which makes it the stronger performer for drying a wider range of materials and doing it more efficiently. That higher temp ceiling is especially useful for tougher filaments like ABS, PA and PC, and it gives you more headroom when a reel is properly soaked through. The S1 Plus is still a useful dryer, and for PLA and PETG it will absolutely do the job for many users, but it is the more basic unit here. If your main goal is maximum drying effectiveness, the S2 wins clearly.

Build quality and design

Winner: Tie

Both are SUNLU official dryers, so you’re getting the same general maker-friendly approach: compact, enclosed, portable, and designed to sit neatly on or near the printer. The S1 Plus is the more straightforward, “easy to use and portable” option, which is appealing if you want something simple and familiar. The S2 feels like the more purpose-built drying tool, with its all-round heating design suggesting a more refined internal layout. In practical terms, both should be fine for everyday workshop use, so neither has a decisive build-quality advantage from the information provided.

Battery life

Winner: Not applicable

These are mains-powered filament dryers, not battery-powered devices, so battery life isn’t a meaningful comparison point. If you were hoping for cordless use, neither product is designed for that. For a filament dryer, mains power is exactly what you want anyway, since steady heat is the whole game.

Price and value for money

Winner: Product A (S1 Plus)

Product A costs £42.99, while Product B is £44.99, so the S1 Plus is £2 cheaper. That is a tiny difference, but when the cheaper option also has the stronger review count, it becomes interesting value-wise. The S1 Plus has 4.3/5 from 1,062 reviews, compared with the S2’s 4.4/5 from 671 reviews. The S2’s slightly better rating suggests it may be the more capable dryer, but the S1 Plus has a much larger review base and costs less. If you want the lowest-risk buy in terms of crowd-tested ownership and don’t need the extra drying headroom, the S1 Plus is the better value pick.

Game library / features

Winner: Product B (S2)

For a filament dryer, “features” means temperature range, heating coverage, and material support. The S2 wins here because 360° all-round heating and 70°C max temperature make it the more versatile tool for PLA, PETG, TPU, ABS, PA and PC. That broader capability is the practical equivalent of having a richer feature set: it handles more demanding situations better. The S1 Plus still supports common materials and is perfectly fine for everyday use, but it’s the less capable machine when you step beyond basic drying.

Overall user experience

Winner: Product B (S2)

If you want the dryer that is most likely to solve moisture problems with the least fuss, the S2 is the better experience. It should be more effective on stubborn spools, more flexible across materials, and more future-proof if your filament collection grows into engineering plastics. The S1 Plus has the advantage of being cheaper and very well reviewed, which makes it attractive for casual users or anyone mainly drying PLA and PETG. But the S2 simply looks like the more serious dryer, and for a tool like this, performance tends to matter more than saving two quid.

Overall summary: the SUNLU S2 is the better filament dryer for most people because it offers stronger heating, a higher max temperature, and better all-round drying capability for only £2 more. The S1 Plus is still a sensible budget buy, especially if you mostly print PLA/PETG and want the cheaper, widely reviewed option. But if you’re asking for the definitive best choice, the S2 is the one I’d put on my bench.