SUNLU Filament Dryer: S1 Plus, S2 or S4, and Which Materials Each One Can Dry
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Buy the SUNLU S2 if you print PETG, ABS or TPU: its higher temperature ceiling dries them properly and the fan circulates air. The S1 Plus is enough for PLA and light PETG use and costs less. The multi-spool S4 is for a multi-material setup or nylon that needs long, hot cycles for several spools at once.
SUNLU’s dryers are the ones most people buy first because they are cheap and sold everywhere. They differ in a way the boxes do not make obvious: maximum temperature and whether there is a fan. Both decide which materials the unit can actually dry rather than just warm. The drying guide lists the temperatures each material needs; match the dryer to that list, not to the price.
Where to buy
The models
- S1 Plus. Single spool, a circulation fan, a timer, print-through feed holes. Temperature ceiling suits PLA and light PETG duty. The right unit for one printer that mostly prints PLA.
- S2. Single spool, higher maximum temperature, fan, humidity display, longer timer. Dries PETG, ABS, ASA and TPU properly and gets nylon most of the way. The sensible default.
- S4 and multi-spool units. Several spools at once with a bigger heater. For a multi-material unit or for drying a week’s filament in one run.
What to check
- Maximum temperature versus your materials. PLA 50 °C, PETG 65 °C, ABS 70 °C, nylon 80 °C and up. Buy the ceiling you need.
- Fan. Without one the outer wraps dry and the core stays wet; drying time doubles.
- Spool width. Standard 1 kg spools fit; 2 kg spools and wide cardboard spools may not.
- Print-through holes so the dryer becomes a dry box during a long print.
- Hygrometer. A humidity reading tells you when the spool is done; without one you guess.
The dryers in the box
The SUNLU S1 Plus is the fan-equipped single-spool unit for PLA and PETG. The Comgrow dryer is a similar single-spool box at the entry level. Creality’s Space Pi X4 is the four-spool, 200 W alternative when you need to dry several spools or reach higher temperatures for nylon; it is here because SUNLU’s own multi-spool unit may not be listed and the X4 is the direct competitor.
Getting the most from a budget dryer
- Dry longer than the manual says. Six to eight hours for PETG, twelve for nylon, because budget heaters run cool at the spool core.
- Print from the dryer with the heater on a holding temperature so the spool stays dry through the job.
- Keep the lid seals clean and the feed holes plugged when not in use.
- If a spool still strings after a full cycle, it needs a hotter dryer, not a longer one.
FAQ
Can the S1 Plus dry nylon? Not properly. It removes some water; nylon wants 80 °C.
Is the S2 loud? The fan is audible in a quiet room, similar to a small PC fan.
Do I need a dryer if I only print PLA? Only if spools sit open for months or strings appear. A sealed box with desiccant covers most PLA users.
LayerWalker
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