| Model | Maximum | Independent zones | Equipment type |
|---|---|---|---|
| SUNLU S4 | 70°C | 1 | Standalone |
| SUNLU S4 Pro | 85°C | 2 | Standalone |
| Creality SpacePi X4 | 85°C | 2 | Standalone |
| Sovol SH03 | 85°C | 2 | Standalone |
| EIBOS Tetras | 65°C | 4 | Compatible AMS add-on |
Draw up your real queue
For each spool, write down the temperature, duration and deadline. Put spools with compatible instructions into groups. That grouping is more informative than the total number of rolls on your shelf.
Choose between shared and separate control
The standard SUNLU S4 has a shared chamber; the S4 Pro offers two independent temperature and time zones. Those are different ways to organize four spools. Neither description implies four separately controlled recipes. Compare exact models, because a similar product name can hide a substantial change in controls.
Account for partially filled batches
A larger dryer can spend much of its life holding one spool. Compare your likely daily use, not just the busiest possible day. The running-cost calculator lets you enter measured average power and a cycle length; rated heater power should not be treated as measured consumption.
Check geometry before capacity claims
The nominal spool count is only the first fit check. Confirm reel diameter, width, axle opening, feeding route and the space needed to open the lid. Photograph or measure your largest spool, then ask the seller about that exact shape if the manual is unclear. A 1 kg label describes filament mass, not a universal reel dimension.
A practical four-spool choice
For four compatible schedules, the standard SUNLU S4 offers one shared chamber with a published 70°C ceiling. The S4 Pro provides two independently controlled zones and a documented 45–85°C range. Both list four nominal spool positions. Choose the control arrangement around the processes you need to run together, then verify the dimensions in each zone.
Four-spool drying is not four-material compatibility
Spool capacity says how many supported reels the system can hold. It does not establish that all materials can share one cycle, that every reel shape fits, or that a connected printer supports those materials. Treat batch compatibility, physical fit and printer compatibility as three separate checks.
Four independent compartments require another equipment check
EIBOS Tetras adds four individually controlled compartments to compatible Bambu AMS equipment. It is a different purchase from a standalone four-spool box, with a 65°C ceiling and an adapter requirement for AMS 2 Pro. Choose it for the supported workflow and separate controls, not solely because four zones is the largest number in a table.
Models to compare
Four-spool chamber
SUNLU S4
Batch capacity with one shared temperature setting.
- Spools*
- 4
- Max temp
- 70°C
- Zones
- 1
Four spools do not mean four independently controlled zones.
Model details →
Two controlled zones
SUNLU S4 Pro
Two temperature and time settings across four spools.
- Spools*
- 4
- Max temp
- 85°C
- Zones
- 2
Two zones offer more scheduling flexibility than one shared chamber.
Model details →
Two controlled zones
Creality SpacePi X4
Four-spool capacity split across two independently controlled chambers.
- Spools*
- 4
- Max temp
- 85°C
- Zones
- 2
The X4 has a published 45–85°C range. Do not substitute specifications for the newer X4L.
Model details →
Two controlled zones
Sovol SH03
Four nominal spools across two independent 45–85°C chambers.
- Spools*
- 4
- Max temp
- 85°C
- Zones
- 2
The 0–99°C display range is not its working range; the specification lists 45–85°C.
Model details →
Four-zone AMS add-on
EIBOS Tetras
Four separately controlled drying chambers for a compatible Bambu AMS.
- Spools*
- 4
- Max temp
- 65°C
- Zones
- 4
An AMS add-on, not a complete standalone dryer. AMS 2 Pro needs the specified printed adapter.
Model details →Sources for this comparison
- SUNLU S4 official product information
- SUNLU S4 Pro official product information
- Creality SpacePi X4 official product information
- Sovol SH03 official product information
- EIBOS Tetras official product information
Specifications checked 13 September 2026. Editorial buying analysis; no hands-on test is claimed.