If you’re picking between electronics cooling systems for a custom industrial product, the honest short answer is: passive in the majority of cases, forced air when the duty cycle or ambient envelope forces it, and liquid or Peltier only when the first two genuinely cannot close the thermal budget. The last category matters, but most teams fight active solutions onto designs that would have run cooler, quieter, and longer with a better passive stack.
This is a comparison piece for hardware engineers scoping cooling on a real industrial build — Arduino Pro Portenta H7, Opta, a custom STM32H7, or anything else that has to hold die temperature in a sealed cabinet at 55 °C ambient. Three cooling families, a comparison table, and our default.
Modern electronic cooling systems
Modern electronic cooling systems group into three families. Most products use one as primary and may borrow from another for hotspots.
Passive: Copper, thermal interface materials (TIMs), heatsinks, vapor chambers, enclosure-stud conduction. No moving parts. No added power draw. Capacity limited by the geometry of the heat path.
Forced air: Fans, blowers, and ducted convection. Significantly higher heat-removal capacity than passive. Adds moving parts, acoustic noise, dust ingress concerns, and a mean time between failure (MTBF) ceiling set by the fan, not the silicon.
Liquid and thermoelectric (Peltier): Closed-loop cold plates, vapor cycles, Peltier spot coolers. Highest capacity. Highest complexity. Reserved for cases where the previous two genuinely cannot.
Electronics cooling systems compared at a glance
The capacity ranges are starting points. Real numbers come from validation against the actual board, enclosure, and duty cycle.
When passive cooling is the right answer
Passive wins whenever the math works. The Portenta H7 is a useful reference point here: the official Arduino datasheet lists maximum board-level draw at 230 mA @ 5 V (~1.15 W total board) with both the Arm Cortex-M7 (480 MHz) and Cortex-M4 (240 MHz) active. On a properly designed baseboard, mounted to an aluminum enclosure stud with a 1 mm gap-filler TIM, that thermal load is comfortable at 55 °C ambient without any active assist.
Layout decisions — copper weight, thermal via density, plane allocation — set the ceiling before the cooling family is even chosen.
Passive cooling also wins on reliability. The fan is the first component to fail in a field-deployed product; eliminating it removes a failure mode entirely. For industrial deployments where field service is expensive or impossible, passive is the safer engineering bet whenever it’s viable.
When forced air earns its place
Forced air is the right answer when the duty cycle precludes throttling, the ambient envelope is genuinely hot, the form factor blocks the conduction path, or compute density pushes total dissipation past what passive can handle. Examples: a multi-core gateway running sustained Ethernet and Wi-Fi telemetry; an edge-AI camera holding 80% utilization on a neural processing unit (NPU) through an entire workday; an enclosure form factor that prioritizes volume over thermal coupling.
When forced air is the answer, treat it like a real engineering decision: pick a fan with telemetry, a real MTBF spec, and dust-tolerant geometry. Design for fan failure as a degraded mode, the firmware reports rather than being a silent killer. And keep the airflow path clean — a fan blowing into a thermal dead end cools nothing.
When liquid or Peltier becomes necessary
Liquid loops and Peltier coolers solve problems passive and forced air can’t — sustained dissipation above ~80 W in a small volume, spot cooling on a single hot package, or environments where forced air would draw contamination through the enclosure. They are also where the failure modes become serious: pump bearings, condensation on the cold side, Peltier hot-side runaway if the hot-side heatsink underperforms.
If a product reaches liquid or Peltier territory, the right move is usually to first re-examine the thermal budget at the architecture level — can the workload be redistributed, scheduled, or throttled to shrink dissipation? Sometimes yes. When the answer is genuinely no, design for serviceability and instrument the loop telemetry as a first-class system.
Our default for custom industrial hardware on Arduino Pro
For most of the custom industrial hardware DeepSea Developments builds on Arduino Pro, the default cooling system is passive with enclosure-stud conduction, sometimes augmented with a top-side heatsink kit for sustained dual-core workloads on Portenta H7. We move to forced air when the duty cycle and ambient envelope force it, and we instrument the firmware thermal management controller either way.
That default is grounded in a four-layer thermal model: get Layers 1–3 right and Layer 4 (active cooling) is usually a tweak, not a rescue. Skip Layers 1–3, and Layer 4 becomes mandatory and expensive.
Pick the cooling system your product actually needs
The electronics cooling system a product needs is the one its real workload, real ambient envelope, and real enclosure geometry require — not the one a previous project used. Every project brings its own challenges, and you must consider every aspect to avoid costly mistakes.
If you’re having issues regarding cooling systems for your industrial product and need some help, you can count on our team. Click on the button below to get a short expert consultation, and also check the Arduino Pro thermal management use case for more information on what we can do.
