Cooling Fan Recommendation Tool
More cooling isn't always better — the right part-cooling fan setting depends entirely on the material.
| Material | Fan speed | Notes |
|---|---|---|
| PLA | 100% | Full cooling almost always improves quality; ease off briefly on the first few layers for bed adhesion. |
| PETG | 20–50% | Too much causes poor layer adhesion and brittleness; too little causes stringing and blobby details. |
| ABS | 0–10% | Cooling causes cracking, warping, and delamination — an enclosure controls temperature instead. |
| ASA | 0–10% | Same reasoning as ABS — retained heat prevents warping and layer splitting. |
| TPU | 30–50% | Enough to set overhangs without over-cooling a material that already needs to print slow. |
| Nylon | 0–20% | Minimal cooling preserves layer bond strength; dry filament matters far more than fan speed. |
| PC | 0% | Cooling causes cracking in this high-temp engineering material; enclosure strongly recommended. |
Bridges are the one common exception
Most slicers automatically override the material's default cooling setting to near-100% specifically during bridging moves, regardless of the material profile — a bridge needs to solidify fast to avoid sagging, and that need outweighs the material's usual cooling preference for that brief unsupported span.
Why some materials actively resist cooling
ABS, ASA, and PC all rely on staying warm layer-to-layer so each new layer bonds well to the one below and internal stresses release gradually instead of locking in — rapid cooling on these materials is what causes the warping, cracking, and layer splitting that gives them a reputation for being difficult to print without an enclosure.
Start from these numbers, then tune per part
A part with lots of small features, overhangs, or bridges often wants more cooling than a large, simple, mostly-vertical part in the same material — slicers let you set cooling per-model or even per-feature for exactly this reason. Treat the table above as a starting profile setting, not a fixed rule for every single print.