The Raspberry Pi 4 delivers impressive power in the same compact form as its predecessors, but higher performance means increased power draw and heat output. Without proper cooling, it throttles under moderate loads. As an experienced Raspberry Pi enthusiast, I've solved this by modifying the official case with a fan for reliable active cooling.
Note: While third-party cases with fans are available, this guide is tailored for DIY makers using the official Raspberry Pi 4 case.
This straightforward modification uses basic household tools. Optional extras (marked below) enhance ease, aesthetics, and performance but aren't essential. I've tested these steps on multiple builds for proven results.
Step 1: Insert the Pi 4 into the case to identify the CPU area on the top (white) half. Drill the fan opening here, avoiding GPIO pins to ensure the case closes properly. Measure precisely—twice, as the saying goes—and use the illustration as a guide.
Step 2: Select a 30mm or 40mm fan. The 40mm option moves more air quietly and efficiently; the 30mm is noisier but fits tighter spaces like aluminum cases. Fan depth (6-20mm) matters—thicker models offer better cooling via larger blades and motors. Skip tall heatsinks or choose low-profile ones.
Step 3: Use a 1-1/4 inch hole saw for 30mm fans or 1-1/2 inch for 40mm for the cleanest cut and optimal airflow. Without a hole saw, multiple brad point drill holes work but reduce efficiency.
Step 4: Place cardboard or foam inside to protect the bottom (red) half from accidental drilling. Secure the case fully assembled for stability.
Step 5: Clamp securely—never hold by hand. I used wood and clamps to prevent slips and injuries from torque.
Step 6: On low speed, start the hole saw gently until it bites, then proceed steadily to avoid warping from heat. Mark and drill four mounting holes using the fan as a template.
Step 7: Cut a side vent near audio/video and power ports for airflow, keeping it shorter than internal mounting points. Use a Dremel or drill holes, then sand with 320-grit for smoothness (optional but recommended). Clean both halves.
Step 8 (Optional): Cut PVC dust filter mesh to fan size, punch mounting holes, and secure fan to case top with hardware, sandwiching the filter.
Step 9: Add dust filter to the GPIO-side vent using thin double-sided tape.
Step 10: Install Pi 4 in bottom half. Add copper heatsinks to CPU, RAM, network, and USB controllers for superior cooling and overclocking stability. Avoid black fabric tape (insulator)—clean and use Arctic Thermal Pads or 3M 8810.
Step 11: Press heatsinks firmly for 15-20 seconds. Connect fan to GPIO (red to 5V, black to GND), minding polarity.
Power up: Smoother video, no throttling in demanding tasks. My setup keeps temps under 50°C at stock, and I've overclocked to 2GHz stably. This mod transforms your Pi 4.
