Cooling Fan Speed Optimizer | PrintCalcLab

Recommended optimal cooling fan speed based on material and print conditions.

Part cooling is a per-material negotiation: PLA wants a hurricane, ABS wants near-still air, and everything else sits in between. The right fan speed also shifts with geometry and settings — steep overhangs and thin, fast layers need extra airflow that flat-walled prints do not. This optimizer starts from a material-specific base speed and adds adjustments for overhang angle, print speed, and layer height, producing a defensible starting percentage instead of a guess.

How It Works

Each material carries a base fan speed: 100% for PLA, 30% for PETG and TPU, 20% for Nylon and HIPS, 10% for ASA, and 0% for ABS and PC, whose layer adhesion and warp resistance collapse under aggressive cooling. The calculator then adds 20% for overhangs steeper than 45° or 40% beyond 60°, 10% when printing faster than 80 mm/s, and another 10% for layers thinner than 0.15 mm, capping the final result at 100%. A PETG print with 50° overhangs at 90 mm/s and 0.12 mm layers, for example, lands at 30 + 20 + 10 + 10 = 70%.

FAQ

Why should ABS be printed with the fan off?

ABS contracts strongly as it cools, and forced airflow makes the surface shrink faster than the interior, driving warping and weak layer bonds. This tool's base speed for ABS — like polycarbonate — is therefore 0%, with airflow added only when geometry such as steep overhangs demands it.

Why do overhangs need more cooling?

Overhanging perimeters are laid partly onto air, so they must solidify before gravity and surface tension drag them down. The optimizer adds 20% fan above 45° of overhang and 40% above 60°, where each new layer has very little supporting plastic beneath it.

Why do fast printing and thin layers raise the fan speed?

Above 80 mm/s the next perimeter arrives before the previous one has shed its heat, and below 0.15 mm the layer count multiplies so heat is delivered to the same region more often. Each condition adds 10% airflow in this model.

Is the recommended percentage a hard rule?

It is a starting point built from common material behavior. Enclosures, duct design, and ambient temperature all change how much cooling actually reaches the part, so refine the output with a small test print — especially for warp-prone materials.