SUNLU Filament Dryer S1 Plus - Quiet Filament Storage & Drying Box

In this review of the SUNLU Filament Dryer S1 Plus the bottom line is simple: this is a compact, easy-to-use drying and storage box for hobbyists and pros who want fewer print failures from moist filament. The S1 Plus focuses on practical drying rather than complex controls, with a simple two-button interface, a built-in circulation fan and spool rollers so you can print straight from the box. For anyone dealing with PETG, PLA+ or flexible filaments that pick up moisture, it noticeably reduces drawing, clogging and adhesion issues.

Key Features

• Moisture reduction: The dryer removes excess humidity from filament to reduce drawing, clogging and poor adhesion during prints.
• Ready out of the box: No assembly is required and the unit runs with two buttons, making it simple for new users to start drying right away.
• Custom drying control: The time can be set from 0 to 24 hours and temperature from 35C to 55C, so users can tailor drying to filament type.
• Run-while-printing design: Two internal rollers and a circulation fan let you feed filament directly while it dries, improving workflow and saving time.
• Ultra-quiet operation: Noise is under 10 dB in operation, so it does not disturb a home office or workshop.
• Wide compatibility: Works with common filament diameters 1.75 mm, 2.85 mm and 3.00 mm and with many brands of filament.

Who It's For

The SUNLU S1 Plus is aimed at desktop 3D printing hobbyists, small workshop users and anyone who prints frequently with moisture-sensitive materials like PETG, PLA+ and flexible filaments. Its simple controls and quiet fan make it a good match for shared workspaces or home setups where ease of use and low noise matter.

Those who need precision lab-grade temperature control or advanced humidity logging should look elsewhere; the S1 Plus is practical and straightforward rather than a high-end environmental chamber. Users who require automated network control or very high drying temperatures should consider a different class of device.

Pros & Cons

Pros

• Effectively reduces filament moisture leading to better print quality and fewer clogs.
• Very easy to operate with no assembly and a simple two-button layout.
• Supports on-the-fly printing with internal rollers and quiet operation under 10 dB.
• Customizable time and temperature settings for different filament types and brands.

Cons

• Temperature control is basic and some users report it warms to around 35C rather than higher set points.
• Not a replacement for a full environmental chamber if precise humidity logging or very high temperatures are required.

Specifications

Product	SUNLU Filament Dryer S1 Plus
Function	Filament drying and storage box with circulation fan
Compatible diameters	1.75 mm, 2.85 mm, 3.00 mm
Time setting	0 to 24 hours (default 6 hours)
Temperature range	35C to 55C
Noise level	Under 10 dB (ultra-quiet)
Extras	Built-in circulation fan, two spool rollers, two-button control

Our Verdict

The SUNLU S1 Plus is a practical, good-value filament dryer for most desktop 3D printing needs; it simplifies filament storage and reduces moisture-related print failures while remaining quiet and easy to use. Hobbyists and small shops who want reliable, plug-and-play drying and the ability to print directly from the spool will find this a useful addition, though users seeking precise temperature performance should verify it meets their needs.

Frequently Asked Questions

Can I print directly from the box?
Yes, the S1 Plus includes two rollers and a circulation fan to allow printing while the filament is kept in the drying box.

What filament diameters are supported?
The unit supports standard filament sizes 1.75 mm, 2.85 mm and 3.00 mm.

How loud is the dryer in operation?
The design is ultra-quiet with reported noise under 10 dB, so it is suitable for home and shared workspaces.