# SUNLU Filament Dryer S4, four-spool 3D printer dryer

The SUNLU Filament Dryer S4 is a four-spool dryer and storage box for 3D printer filament. Its listing describes automatic humidity-triggered drying, three internal fans and connections for feeding up to four printers, making it aimed at multi-spool setups rather than users drying one roll at a time.

- [Original product page](https://bargainpostbox.co.uk/product/sunlu-filament-dryer-s4-four-spool)
- [View offer](https://bargainpostbox.co.uk/visit/sunlu-filament-dryer-s4-four-spool)
- Market: UK
- Language: en-GB
- Currency: GBP
- Brand: SUNLU
- Model: SUNLU Filament Dryer S4
- Price: 84.99 GBP
- Previous price: 99.99 GBP
- Discount: 15%
- Price checked: 2026-11-12T15:52:17.017Z
- Rating: 4.6 / 5
- Reviews: 653

Prices and deal status are the latest recorded data, not a guarantee of availability. Confirm the price and availability with the store.

## At a glance

- Room for four 1 kg spools is intended for multi-colour or multi-printer workflows.
- Automatic drying is described as starting when humidity reaches the chosen range and stopping below 25%.
- The listing specifies three fans and claims temperature balance within ±3℃.
- Eight feed holes are stated, alongside a claim of connection to four printers at once.

## Pros

- Four-spool capacity can reduce the need to rotate rolls through a smaller dryer.
- Selectable humidity control and automatic start/stop can reduce manual monitoring.
- Three fans are intended to circulate air across the enclosure.

## Specifications

### Identity
- Brand: SUNLU
- Model: SUNLU Filament Dryer S4
### Dimensions and installation
- Weight listed: 4 Kilograms
### Materials and protection
- Material listed: S4 Dryer Filament
- Colour: black
### Capacity and connections
- Spool capacity claimed: 4 spools 1KG 3D Printer Filament simultaneously
- Printer connections claimed: supports connection to 4 printers simultaneously
- Feed holes described: 8 Feed Holes
### Heating and air circulation
- Heater: 350W PTC heater
- Warm-up claim: In just 30 minutes, it heats up from 25℃ to 50℃
- Fans: three build-in fans – two circulating fans on the sides and 1 on the bottom
- Temperature balance claimed: within ±3℃
### Humidity control
- Adjustable humidity range: 30%~50%
- Drying stop threshold: below 25%
### Compatibility
- Printer type claimed: all FDM 3D printers
- Filament compatibility claimed: accommodating 99.99% of filaments in the market

## Before you buy

- Listing claims such as four spools, four printer connections, 350W heating and the stated humidity behaviour are manufacturer descriptions, not independently verified performance measurements. The claimed 30-minute warm-up applies to heating from 25℃ to 50℃. The listing says the selected humidity range is 30%~50% and drying stops below 25%, so operation may not match a single fixed humidity target.

## A good fit for

- Users drying or storing several filament spools together.
- Multi-colour or multi-printer FDM setups that can make use of multiple feed paths.
- Buyers who want selectable humidity-triggered drying rather than only manual operation.

## Less suited to

- Users who only need a compact dryer for one spool.
- Buyers needing independently verified heating, humidity-control or compatibility performance.

## Customer feedback

Customer feedback describes the dryer as easy to use and reports positive experiences with drying performance, print quality, customisable settings and appearance. Heating feedback is mixed: customers report quick heating but also note that it generates a fair amount of heat. That concern is relevant for a heated enclosure, while the four-spool capacity and humidity features are product claims rather than proof of individual customer outcomes.
- Positive themes: Customer feedback describes drying performance and day-to-day operation positively.
- Positive themes: Customers mention ease of use, print quality, customisable settings and appearance.
- Mixed feedback: Heating feedback is mixed, with reports of quick heating alongside comments that the unit generates a fair amount of heat.

## Frequently asked questions

### How many spools can the SUNLU S4 hold?
The listing claims it can hold four 1 kg filament spools at once.
### Does the S4 adjust drying automatically?
The listing describes adjustable humidity from 30%~50%, with drying starting when humidity reaches the selected range and stopping below 25%.
### Can it feed more than one printer?
The listing claims connections for four printers simultaneously and describes eight feed holes. Confirm the selected listing and your printer arrangement if this capacity is essential.
### How quickly does it heat up?
The claimed warm-up is 30 minutes from 25℃ to 50℃. This is a listing claim, not an independently verified result.

## Alternative options

- [SUNLU S2 3D Printer Filament Dryer, Filament Dry Box S2 with Airflow Fan, Reduce Moisture During 3D Printing, Filament Dehydrator 360° Surrounding Heating, SUNLU FilaDryer S2, Filament Holder, Black](https://bargainpostbox.co.uk/visit/sunlu-filament-dryer-s4-four-spool)
- [ELEGOO Smart Mini Heater for Resin 3D Printer, Air Filtration \| Smart mini heater, temperature control, air filtration, improves curing for MSLA/DLP/LCD printers](https://bargainpostbox.co.uk/visit/sunlu-filament-dryer-s4-four-spool)
- [SUNLU Filament Dryer Box S2, Up to 70°C with 360° Surround Heating \| 3D Printer Filament Dryer Keeps Filament Dry During 3D Printing, Compatible with PLA/PETG/ABS/SILK/PA/PC, Black](https://bargainpostbox.co.uk/visit/sunlu-filament-dryer-s4-four-spool)
- [Creality Official Space PI Filament Dryer, 3D Printer Filament Dryer Box with Built-in Fan Filament Storage Filament Dehydrator for 1KG 1.75/2.85mm One-Key Setting for PLA PETG ABS TPU Nylon](https://bargainpostbox.co.uk/visit/sunlu-filament-dryer-s4-four-spool)
- [YOOPAI Filament Storage Box, 6 Pack Airtight Filament Containers with Desiccant & Labels, Clear 4L 3D Printer Filament Boxes for 1kg 1.75mm PLA PETG ABS TPU Spools, Moisture & Dust Protection](https://bargainpostbox.co.uk/visit/sunlu-filament-dryer-s4-four-spool)
- [YOOPAI 3D Printer Filament Storage Box, Filament Storage Rack with Transparent Cover, 2-Tier Metal Filament Spool Holder, Holds up to 20 x 1kg Rolls, Filament Organiser for Home, Workshop, Studio](https://bargainpostbox.co.uk/visit/sunlu-filament-dryer-s4-four-spool)
- [Creality Official Space PI Filament Dryer, 3D Printer Filament Dryer Box with 360° Heating, Upgraded Filament Dehydrator Storage Box Support PLA ABS PETG TPU 1KG 1.75/2.85mm](https://bargainpostbox.co.uk/visit/sunlu-filament-dryer-s4-four-spool)
- [Creality Filament Dryer Box 2026 Upgraded, SpacePi SE Upgraded 65° PTC Heating with Fan, Dust & Moisture-Proof Storage, 3D Printer Filament Spool Holder, Dehydrator for 1.75mm/2.85mm PLA PETG ABS TPU](https://bargainpostbox.co.uk/visit/sunlu-filament-dryer-s4-four-spool)
- [Comgrow 3D Printer Filament Dryer Box SH01, 3D Filament Storage, Keeps Filaments Dry During 3D Printing, Compatible with 1.75mm/2.85mm PLA PETG ABS Material, Filament Dryer, Spool Holder](https://bargainpostbox.co.uk/visit/sunlu-filament-dryer-s4-four-spool)
- [Sovol Filament Dryer SH02, 3D Printer Filament Dryer Box for PLA PETG TPU \| Filament Dehydrator with PTC Heater, Touch Screen, One Key Set, Sealed Storage, Spool Holder, PLA PETG TPU ABS 1.75/2.85mm](https://bargainpostbox.co.uk/visit/sovol-sh02-dual-spool-filament-dryer)

## Add-ons

- [Filament Joiner SUNLU Filament Connector with 200PCS PTFE Sleeve for 3D Printer Filament 1.75mm, 240°C Fast Heating Filament](https://bargainpostbox.co.uk/visit/sunlu-filament-dryer-s4-four-spool)
- [ELEGOO PLA+ 3D Printer Filament 1.75mm Black 4KG \| PLA Plus Tougher and Stronger, Dimensional Accuracy +/- 0.02mm, 4 Pack 1kg](https://bargainpostbox.co.uk/visit/sunlu-filament-dryer-s4-four-spool)

## Images

![SUNLU Filament Dryer S4, four-spool 3D printer dryer — 1](https://bargainpostbox.co.uk/i/oGsCelI052qDLH-J3gCPOkbIoouQ9wFmNfnlq3PJ4YKFl45VDy4z6FKTyXsRHaSDoKY_6XGehdSy3rSlFsUdrMLuuc9RzZjqLt7uBDX3fObAow8BoxQ1ZSYR.jpg)

![SUNLU Filament Dryer S4, four-spool 3D printer dryer — 2](https://bargainpostbox.co.uk/i/oYPzuYB9VcQmu5xvGwph6lkFLMJvOknxuSrd2MvfkJMejzDGrxHcLnLkXhvR16oNuRAsZBXW69hCi0NjV2_XDyjbzhF1xmOQ54kOgt6v1JDyhUTCgMP1dT87.jpg)

![SUNLU Filament Dryer S4, four-spool 3D printer dryer — 3](https://bargainpostbox.co.uk/i/At8R3t9noCaVD7IOPvAFk7v-uuPd4dVdohLEISmHwMQp0b0ZVXFP0AgFxzRDN4tuQOnhkMS-PdJG2RAZdWxiog1KnWCyn6ikRdSPTAoj_4DRvP8GiwW4iuSJ.jpg)

![SUNLU Filament Dryer S4, four-spool 3D printer dryer — 4](https://bargainpostbox.co.uk/i/pulxFIi4usLqfDKyms67lGtpdMK9swFcLbQQZzP5hAE5E04QK9JSRmcj0du-YksRZYyzLYDAgNSSkBLg4RzMnlcfCotQ6m_Tb24Gi4uE2vIobyYHFHsGzy5r.jpg)

![SUNLU Filament Dryer S4, four-spool 3D printer dryer — 5](https://bargainpostbox.co.uk/i/N2ua_0B1VNB-0CqjZU2Dc24hb1eomP90peTs7qBKBx1b8gmlFUfpYgSIKVAjPzURx2yMAFwQic-UEvhBq6pqUfGAHfDHZiwQ6V-zyzK2Fy-3jGJA5HqXaMji.jpg)

![SUNLU Filament Dryer S4, four-spool 3D printer dryer — 6](https://bargainpostbox.co.uk/i/LYGiz8pk7WXnWEVoR__4bW9AMOWkWXVduxN1KnbGuSd2p6iK1LiTkeZElmwYmTCslG98PmI_iJc7TQcrLMHAqNOhMKKx1ambVSJAntWDMW9e5opu8JDQmBun.jpg)

![SUNLU Filament Dryer S4, four-spool 3D printer dryer — 7](https://bargainpostbox.co.uk/i/9FASmr8F3YRRjGA_ptpGxeerWvWeuYnc_nZhz_I-KunKdDU7qHzRSKUUmjozTpg3eg_CSLuQiLh5CwBbBXXGvCxVbOMXg_3xqnxdCRPdNpUxYE7tNvUSv5j0.jpg)