SUNLU FilaDryer SP2 vs S2

Who this comparison is for

This page is for anyone choosing between two of SUNLU's 70 °C dryers: the FilaDryer SP2 (heating base and storage box set) and the FilaDryer S2 in Black. They heat to the same maximum, so the real questions are how big your spools are, how many you dry at once, and whether you want the dryer to double as sealed storage. If you need more than 70 °C, see our SUNLU FilaDryer E2 vs S2 comparison. If you're not sure you need a heated dryer at all, start with our filament dryer vs dry box guide. The S2 is also compared in our SUNLU FilaDryer S2 vs Polymaker PolyDryer and eSUN eBOX Lite vs SUNLU FilaDryer S2 pages. For more options, see the filament dryer shortlist and the filament storage shortlist.

How we compared them

This is a research-based comparison. Every figure below comes from SUNLU's own store pages, product pages, wiki, comparison blog, and user manuals, listed in the sources. We haven't tested either dryer, so nothing here is a measured result of ours. Where SUNLU describes its own product, such as a "foolproof" heating process, we label it as the maker's claim.

Both manuals are image-only PDFs with no text to extract, so we rendered their pages and read the printed text. The SP2's user manual is a 15-page PDF with 12 numbered pages. The S2's "User Manual" link opens a one-page "User Guide" with a drying table and short setup steps.

Side-by-side specs

Spool size and capacity

This is the biggest practical difference.

• SUNLU FilaDryer SP2. The store page says the box "can hold two rolls of 1kg filaments, one roll of 2kg (2 rolls of 2kg filaments for SUNLU), and 3kg filaments," with a maximum spool of 250 mm across and 153 mm wide. The manual's spec table gives the same Φ250 mm × 153 mm and "1kg×2 or 2kg×1 or 3kg×1." Notice that the store page's description says two 2 kg spools fit only for SUNLU's own spools. The same store page's title and spec table, and every other SUNLU page, say one 2 kg spool, so plan on one unless your spools are SUNLU's. The manual says 1, 2, and 3 kg spools sit on the roller shaft, while 0.25 kg and 0.5 kg spools are threaded onto the included spool roller. SUNLU's store page says the roller also lets you use paper spools and "Even damaged spools."
• SUNLU FilaDryer S2. SUNLU's wiki gives a maximum of φ210 × 85 mm, and its blog says the S2 "Holds one standard 1 kg spool."

So the SP2 takes spools 40 mm larger across and 68 mm wider, which is what 2–3 kg spools need. Spool sizes vary by brand, so measure yours before you buy either.

Temperature and drying settings

Both dryers have the same 35–70 °C setting range. SUNLU gives a heat-up time only for the SP2: 70 °C in 15 minutes, on its product page and wiki.

SUNLU's two manuals print different drying tables, and they don't agree on the same materials:

The S2 table also lists HIPS and PMMA at 50–55 °C. SUNLU doesn't explain the differences, and these are general settings, not your filament maker's. Follow the drying guidance for your exact spool, and check whether it needs more than 70 °C, which neither dryer reaches.

SUNLU is inconsistent about whether 70 °C is enough for engineering materials:

• S2 product page: "Supports heating up to 70°C, suitable for specialty filaments such as PA and PC."
• SP2 store page: lists "PA/PC etc." among its materials.
• SP2 manual: its drying table gives PA/PC 65–70 °C for 10–12 hours.
• SUNLU's comparison blog: lists "Not suitable for high-temp engineering filaments" as an S2 con. That blog doesn't cover the SP2, which has the same 70 °C maximum.

Heating and airflow

The two dryers heat in different ways. The SP2 puts a "PTC heater with metal roller fan" in its base, under the storage box, according to its product page and wiki. The S2 uses "Dual upper and lower heating plates with a bottom fan," which SUNLU calls "360° Enclosed Heating."

The power figures are far apart. The S2 lists a 48 W maximum working power. The SP2's figures vary by page:

• Store spec table and manual: 250 W maximum working power.
• Product page and wiki: 250 W rated.
• Store description: "200W PTC + fan heating."
• Store page and manual: a "Maximum Operating Current" of 2.2 A at 230 V and 4.2 A at 120 V, which works out to about 500 W at those voltages, double the 250 W SUNLU lists. SUNLU doesn't explain this.

The SP2 plugs into mains power directly, while the S2 runs from an external 24 V DC adapter. SUNLU doesn't publish drying-time or energy-use test results for either.

Humidity, timer, and controls

• SUNLU FilaDryer SP2. The base's screen shows the current and set temperature, the filament type, and the time, according to the manual. Humidity comes from a separate hygrometer that you fit into a groove in the storage box, with a desiccant box. The spec table lists the humidity display as "Refer to the Hygrometer:10%-90%." SUNLU's store page calls it "an independent hygrometer for real-time observation of internal humidity changes." The manual lists a 0–99 hour timer and presets for PLA, PETG, TPU, ABS, PA, and PC, with the set temperature adjustable from 35 to 70 °C. To switch off, you double-click the power button, and the manual says "the fan will shut down after 3 minutes" to stop heat building up inside. It also lists °C/°F switching and settings for the light strip.
• SUNLU FilaDryer S2. The product page and wiki list a 4.6-inch LCD that shows "temperature, time, humidity, filament type, and countdown," and the wiki and store page add one-touch presets and an LED ring for status. The store page's description calls the screen "3.42*2.87 inches" in one place and a "2 inch large LCD screen" in another, but its feature panel says 4.6 inches. SUNLU doesn't publish the S2's timer range or humidity range.

Storage after drying

Only the SP2 is designed as sealed storage. SUNLU says its top and bottom covers have silicone seals, and that "under an average ambient humidity of about 50%, an average of about 25% humidity can be maintained inside" the box. That's SUNLU's own measurement, with no method published. After drying, the manual says to lift the box off the base, fit the two airlocks to the bottom, and plug the outlet holes "tightly" with the silicone stoppers. SUNLU sells extra storage boxes without the base (the "Storage Box Set," which its store page lists with two spools of PLA+ 2.0 included) and recommends stacking at most 3.

SUNLU calls the S2 "a drying and storage box," but its pages don't describe any seal or give an inside-humidity figure.

Printing while drying

SUNLU is explicit about the S2. The store page says it "Allows you to print while drying," and that its feed-out coil lets filament "continue to dry in the dryer as it's being fed to the printer." The blog lists "Print-while-drying capability with PTFE tube output."

For the SP2, SUNLU describes feeding a printer from the box but doesn't say in so many words that you can print during a drying cycle. The store page says the box has "3 cable outlet holes on each side of the box to meet the printing needs of different sizes of filaments," and the wiki says "horizontal axis mounting allows secure printing." The manual says to put the PTFE tube into the rubber stopper and feed the filament through it. Separately, the manual recommends removing the silicone stopper from the feed hole during drying "to allow effective moisture expulsion." Neither SUNLU page names a printer or multi-material feeder it has tested with either dryer, so we make no compatibility claim.

Spool temperature limits

At 70 °C, both dryers reach the limit SUNLU warns about. The SP2 manual says that when you set 70 °C, the spool should have a temperature tolerance above 70 °C "to avoid deformation," and the store FAQ says a spool used at 70 °C or more should be rated for at least that. SUNLU doesn't print this warning on the S2 pages we checked, but the S2 also reaches 70 °C, so the same check makes sense. Plastic spools vary, so look up your spool's rating before drying at the top of the range.

Size and weight

SUNLU lists the SP2 at 278 × 208 × 396 mm (L × W × H) and 3.6 kg. It lists the S2 at 265 × 274 × 118 mm (L × W × H) and 1109 g on its product page (1.19 kg in its blog). By those labels, the SP2's listed height is more than three times the S2's, so check shelf height if it'll sit under a cabinet. SUNLU's store page claims the S2 runs at "less than 10db while operating." SUNLU publishes no noise figure for the SP2.

What SUNLU says each is for

• SUNLU FilaDryer SP2. SUNLU calls it "a dual function drying box created to offer both drying and storage capabilities," and says its "split modular design combines 3D filament drying and 3D filament storage," with an "Ideal for both 3D printing professionals and hobbyists" pitch.
• SUNLU FilaDryer S2. SUNLU calls it "designed as a drying and storage box for 3D printer filaments," and its blog suggests it for "Beginners, students, or anyone with a single printer and limited space," especially those who "mainly print PLA and PETG."

SUNLU

SUNLU FilaDryer SP2 (Heating base + storage box set)

Best for

Readers who want one unit that dries a spool and then keeps it sealed, including 2–3 kg spools.

Skip this if

You need to dry more than two 1 kg spools at once or need temperatures above 70 °C.

Specs, strengths, and limitations

Capacity

Two 1 kg, one 2 kg, or one 3 kg spool (0.25–3 kg spools); maximum spool Φ250 mm diameter × 153 mm width (SUNLU store spec table and manual; the store description alone says '2 rolls of 2kg filaments for SUNLU')

Outer size

278 × 208 × 396 mm

Part rated to

70 °C (your printer's own hotend limit may be lower)

Maker notes

Two-part design: a heating base plus a detachable, stackable storage box (SUNLU recommends stacking at most 3 boxes). SUNLU's store page description says '200W PTC + fan heating'; the store spec table lists 'Maximum Working Power: 250w', and the SUNLU wiki lists rated power 250 W. SUNLU wiki: heats to 70 °C in 15 minutes; product size 278 × 208 × 396 mm (L×W×H); internal size 265 × 193 × 274 mm. Storage box has silicone seals on the top and bottom covers and an independent hygrometer; SUNLU states about 25% inside humidity at about 50% ambient. SUNLU states a spool roller lets paper spools and damaged spools be used. Compatible with 1.75 mm and 2.85 mm filament; 3 outlet holes on each side. Store spec table and manual: work temperature 35–70 °C, time setting range 0–99 h, humidity display 'Refer to the Hygrometer: 10%-90%' (separate hygrometer in the storage box, not on the base screen); maximum operating current 2.2 A @ 230 V / 4.2 A @ 120 V, which SUNLU does not reconcile with its 250 W maximum working power.

Strengths

• Manufacturer states the storage box lifts off the heating base, so the same box is used for drying and sealed storage.
• Manufacturer states a maximum spool of Φ250 × 153 mm, including 3 kg spools.
• Manufacturer states a spool roller supports paper and damaged spools.

Limitations

• 70 °C maximum.
• SUNLU's own pages give different heater figures (200 W PTC in the store description vs 250 W maximum working power in the store spec table and 250 W rated in the wiki).

View on Amazon ↗ (opens Amazon in a new tab)Details checked 2026-10-06 against the manufacturer. Price and availability are on Amazon.

SUNLU

SUNLU FilaDryer S2 (Black, single-spool dryer)

Best for

Drying and feeding one standard 1 kg spool of PLA, PETG, or TPU at a time.

Skip this if

You need to dry several spools at once or need temperatures above 70 °C.

Specs, strengths, and limitations

Capacity

One spool up to 210 mm diameter × 85 mm wide (SUNLU wiki: max capacity φ210×85(H) mm; SUNLU comparison: one standard 1 kg spool)

Outer size

265 × 274 × 118 mm

Part rated to

70 °C (your printer's own hotend limit may be lower)

Maker notes

Temperature setting range 35–70 °C (SUNLU wiki). Max working power 48 W (SUNLU product page and wiki). SUNLU describes dual upper and lower heating plates with a bottom fan ('360° Enclosed Heating') and a real-time humidity readout. Filament diameters 1.75 / 2.85 / 3.00 mm (SUNLU store page); SUNLU wiki lists 1.75 / 2.85 / 3.01 mm. SUNLU dimensions are 265(L) × 274(W) × 118(H) mm; recorded here as width = L, depth = W. SUNLU pages give different screen sizes (4.6-inch on sunlu.com, other figures on the store page), so screen size is not recorded. Timer range is not stated on SUNLU's product pages.

Strengths

• Manufacturer states a 35–70 °C setting range with heating plates above and below the spool and a bottom fan.
• Manufacturer states filament can keep drying while it feeds to the printer.
• Manufacturer lists a low 48 W maximum working power.

Limitations

• Holds a single spool, and SUNLU lists a maximum spool size of 210 mm diameter × 85 mm width, so wide or 2–3 kg spools will not fit.
• 70 °C maximum is below the drying temperature some engineering filaments call for; check the filament maker's drying guidance.

View on Amazon ↗ (opens Amazon in a new tab)Details checked 2026-10-06 against the manufacturer. Price and availability are on Amazon.

Verdict: which should you buy?

These two don't compete on heat: both stop at 70 °C, so neither is the dryer for filaments whose maker calls for more. The difference is capacity and storage. By SUNLU's documents, the SP2 trades a tall box and a much bigger heater for big spools, two spools at once, and sealed storage afterwards. The S2 suits a single 1 kg spool within φ210 × 85 mm, and it's the only one of the two SUNLU explicitly says can print while drying.

Choose the SUNLU FilaDryer SP2 if…

• You use 2 kg or 3 kg spools, or spools wider than 85 mm or larger than 210 mm across.
• You want to dry two 1 kg spools together.
• You want the dried spool to stay in a sealed box with its own hygrometer, and you might add more boxes later.
• You have room for a box nearly 400 mm tall.

Choose the SUNLU FilaDryer S2 if…

• You dry one standard 1 kg spool at a time.
• You want to feed the printer from the dryer while it runs, which SUNLU states directly for the S2.
• You want humidity on the same screen as the temperature and timer, and a much smaller, lighter box beside the printer.
• You'd rather use a 48 W unit on a 24 V adapter than a 250 W mains heater.

Safety and limits

How this page was checked

Every specification, temperature, and claim above comes from SUNLU's pages and manuals in the sources section, retrieved on 2026-10-14. We haven't used either dryer for this page, so nothing here is a measured result of ours. We read the manuals' printed text from rendered pages and haven't drawn anything from the product photos or illustrations. Where SUNLU's pages disagree (the SP2's heater power, current, and 2 kg capacity; the S2's screen size, weight, and largest filament diameter; the two drying tables), we've reported each figure with where it appears, without choosing. The S2 store page's FAQ section answers questions about SUNLU's AMS Heater rather than the S2, so we didn't use it. Customer reviews weren't used. Read more in our editorial standards and affiliate disclosure.

Dryers & dry boxes: what to check before you buy ↗