SUNLU S4 vs Creality Space Pi Plus: Which Filament Dryer Makes More Sense for 3D Printing?

May 31, 2026

If you already know you need to dry filament and the real question is which dryer lane makes more sense, this comparison is cleaner than a generic “best dryer” list. These two boxes solve slightly different problems even though they overlap for PETG, TPU, ABS, ASA, nylon, and other moisture-sensitive spools.

Short answer: buy the SUNLU Filament Dryer S4 if you want higher spool capacity and a stronger fit for people juggling multiple active materials. Buy the Creality Space Pi Filament Dryer Plus if you want a simpler 2-spool dryer that still supports dry-while-printing use without jumping to a larger 4-spool box.

Quick comparison summary

Buy the SUNLU S4 if you regularly keep multiple spools in rotation, want a stronger small-farm or heavier hobby bench fit, or want the bigger-capacity answer first.
Buy the Creality Space Pi Plus if you want a more compact dual-spool dryer, mostly run one or two active materials at a time, or want to stay below the footprint and cost of a 4-spool lane.

Fast-scan compare

Category	SUNLU S4	Creality Space Pi Plus
Capacity	4 spools	2 spools
Drying temperature	up to 70C	notable broad-material support, but the pitch is more about dual-spool convenience than maximum box size
Dry-while-printing fit	strong if you keep several spools conditioned and ready	strong if you mainly feed one or two active spools through a simpler setup
Best buyer fit	makers, small print farms, heavier bench workflows, more active material rotation	makers who want a more compact 2-spool answer without moving back to single-spool habits
Main tradeoff	bigger box, bigger footprint, more machine than some casual users need	less capacity if your real problem is juggling multiple open spools all week

Who each dryer is for

SUNLU S4

The S4 makes the most sense when your drying problem is not one wet spool. It makes sense when your bench keeps several active materials open at once and you are tired of rotating single-spool or smaller dual-spool solutions through the same recovery cycle. That makes it the stronger choice for people printing a mix of PETG, TPU, ABS, ASA, nylon, or support materials with real frequency.

4-spool capacity
up to 70C max drying temperature
350W PTC heater
triple circulation fan airflow
supports 1.75mm, 2.85mm, and 3.0mm filament

Check SUNLU S4 on Amazon

Creality Space Pi Plus

The Space Pi Plus makes more sense when you want a real dual-spool dryer, want to print from the box more directly, and do not actually need a 4-spool station living on the bench all the time. It is the easier answer for many serious hobby users who want something better than basic storage discipline without committing to higher-capacity gear.

2-spool capacity
360 degree heated-air circulation
LCD control screen
direct-print drying with dual filament ports and PTFE tubes
supports PLA, PETG, ABS, TPU, PC, PP, ASA, and PETG-CF

Check Creality Space Pi Plus on Amazon

Where the SUNLU S4 wins

Capacity first: four spools changes the workflow more than a small feature tweak does.
Better for rotation-heavy benches: if multiple materials stay active, the bigger box is easier to justify.
Stronger small-farm fit: the S4 is easier to defend when the bench is closer to production than casual hobby use.

Where the Creality Space Pi Plus wins

Simpler dual-spool ownership: it covers the common case where one or two active spools matter most.
Easier to justify for normal maker use: it feels less like overbuying when you do not need 4-spool capacity.
Cleaner middle ground: it sits between too-small single-spool habits and a more bench-dominant larger dryer.

Which one makes more sense for PETG, TPU, nylon, and other moisture-sensitive materials?

Both are believable picks for moisture-sensitive workflows. The real split is not basic compatibility. The real split is whether your drying problem is a capacity problem or a one-or-two-spools-at-a-time problem.

If you regularly keep multiple materials open, the SUNLU S4 is easier to justify because it reduces rotation friction. If your workflow usually narrows down to one or two loaded materials, the Creality Space Pi Plus is often the cleaner buy because it solves the real issue without taking over more bench space than necessary.

Price and value logic

Do not treat this like a feature checklist fight. Treat it like a workflow purchase. The cheaper wrong-capacity dryer can be a worse value than the slightly more expensive one that actually matches how many spools you keep active. At the same time, a bigger dryer is not automatically better if your real use never goes past one or two working spools.

Final recommendation

Buy the SUNLU Filament Dryer S4 if your drying workflow is already broad enough that a 4-spool lane will save real friction. Buy the Creality Space Pi Filament Dryer Plus if you want the smarter dual-spool answer and do not need a larger bench commitment.

Choose the next dryer step

Still leaning SUNLU S4 because capacity is the real issue? Open the full S4 review before one comparison decides the whole bench workflow.
Still leaning Space Pi Plus because two-spool simplicity feels right? Open the full Space Pi Plus review before you assume a smaller box is automatically the better value.
Not sure whether you even need a dryer, a dry box, or just better storage? Use the broader moisture-control guide first.
Mainly buying around PETG or TPU instead of general bench capacity? Use the PETG-and-TPU dryer roundup when the real question is material fit, not just S4 versus Space Pi Plus.

Use reviews as part of the decision, not the whole decision.

Move from the reviewed tool into the print problem, process fix, workflow question, or production help path that actually decides whether the purchase makes sense.