PC Cooling: Water vs. Air (and Robots)

Gamers spend thousands on RGB fans, massive Noctua air coolers, and custom liquid-cooling loops to keep their GPU at a chilly 60°C. Why? Because Heat is the Enemy of Electronics.

In a computer, heat kills performance. In a robot, heat kills the match.

Why Electronics Get Hot

Whether it’s an NVIDIA RTX 4090 or a GoBilda 5202 Motor, the physics are the same: Resistance.

• As electricity flows through copper wires, it encounters friction.
• This friction turns electrical energy into Heat Energy ($$P = I^2R$$).
• The Trap: As copper gets hotter, its resistance increases. This causes more heat. It is a runaway thermal loop.

Thermal Throttling

Your PC has a safety feature. If the CPU hits 100°C, it automatically slows down (“Throttles”) to prevent melting. Your FPS drops from 144 to 30. Robots do the same thing, but worse.

• Motor Fade: As the magnets in a motor heat up, they lose their magnetic field strength (temporarily). The motor physically becomes weaker.
• The Outcome: In the first 30 seconds of the match, your robot is fast. In the last 30 seconds (Endgame), your robot is sluggish and can’t climb the hill. You lost because of thermodynamics.

Solving the Heat Problem

1. Air Cooling (Passive)

Just like a standard CPU cooler, motors have aluminum cases that act as Heat Sinks. They absorb heat from the core and radiate it into the air.

• The Flaw: Air is a terrible conductor. If the air inside the robot is stagnant, the heat has nowhere to go.

2. Active Cooling (Fans)

Smart teams attach 3D-printed shrouds and 40mm fans to their motors (yes, little PC case fans). This forces fresh, cool air over the fins.

• Data: A cooled motor might stay at 40°C. An uncooled motor hits 75°C. That 35-degree difference is significantly more power efficiency.

3. Water Cooling (The Industrial Solution)

We can’t put water on an FTC robot (it’s illegal for obvious reasons). But industrial robots (like those welding car chassis) use water jackets. Water absorbs heat 24x better than air. In extreme cases, teams use “Freeze Spray” (Upside down compressed air) between matches to super-cool their motors instantly. It’s the “Nitrous” of cooling.

Conclusion

If your gaming PC throttles, you lose a round in Valorant. If your robot throttles, you burn out a $40 motor and lose the Championship. Managing airflow, monitoring temperatures, and understanding thermal mass is often the difference between a robot that is “fast for 1 minute” and a robot that is “fast for the whole match.” So yes, putting a fan on your robot is exactly the same engineering principle as building a custom loop for your PC.