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Raspberry Pi 5 Active Cooler: Installation, Specifications, and Thermal Testing

Learn what the Raspberry Pi 5 Active Cooler does, how to install it safely, and how to compare temperatures during a controlled CPU stress test.

The official Raspberry Pi 5 Active Cooler combines an anodised aluminium heatsink, thermal pads, retaining pins, and a temperature-managed blower fan. It is designed specifically for Raspberry Pi 5 and helps limit operating temperature during prolonged or intensive workloads.

Active cooling is useful when the processor must sustain high performance for tasks such as compiling software, emulation, server workloads, computer vision, and stress testing. A cooler can also reduce the chance of thermal throttling, which is the automatic reduction of processor performance used to control excessive temperature.

What the Active Cooler Does

A passive heatsink spreads processor heat into surrounding air but has no powered airflow. A case fan moves air through an enclosure but may not make reliable thermal contact with the processor. The Active Cooler combines both functions: its thermal pads transfer heat to the heatsink, and its blower fan directs air through the assembly.

A thermal pad is a compressible thermal interface material. It fills small gaps between the board components and the metal cooler, improving heat transfer. The heatsink then releases that heat to the moving air.

The fan is temperature controlled. It does not necessarily run continuously at its maximum speed. PWM, or pulse-width modulation, varies the fan drive to balance cooling and noise. A tachometer signal reports fan rotation, helping the system determine whether the fan is operating.

Design and Technical Specifications

The cooler receives 5 V DC through the Raspberry Pi 5's dedicated four-pin FAN header. The header provides the fan's power and control connections. Its blower design directs airflow through the heatsink rather than simply stirring air around the board.

Raspberry Pi 5 Active Cooler Specifications

Power input: 5 V DC through the four-pin FAN header. This supplies the accessory from the board's dedicated fan connection.

Control: PWM with tachometer feedback. PWM manages fan speed, while tachometer feedback reports rotational operation.

Maximum airflow: 1.09 CFM. CFM means cubic feet per minute and describes airflow volume.

Maximum speed: 8,000 RPM, with a tolerance of plus or minus 15 percent. RPM means revolutions per minute.

Material: Anodised aluminium. The metal conducts heat away from the processor area.

MTTF: 379,000 hours at 25 degrees Celsius. MTTF, or mean time to failure, is a statistical reliability estimate under specified conditions; it is not a promise that every fan will operate for that exact duration.

Production commitment: Availability is stated through at least January 2036.

Before Installation

  1. Remove all power. Shut down the operating system, disconnect the power supply, and wait until the board is completely unpowered before touching it or fitting the cooler.
  2. Identify the processor and cooler mounting area, the two dedicated heatsink holes, and the connector marked FAN.
  3. Check nearby board connectors, GPIO accessories, cables, and any case structure that could collide with the cooler or its fan lead.
  4. Confirm that the intended case has enough height and side clearance. A case designed for an uncooled board may not close over the Active Cooler.
  5. Handle the thermal interface surfaces cleanly. After removing protective films, do not touch the exposed thermal pads with fingers or allow dust, grease, or cable debris to contaminate them.

How to Install the Raspberry Pi 5 Active Cooler

  1. Place the unpowered Raspberry Pi 5 on a clean, stable, non-conductive work surface.
  2. Turn the cooler over and remove the protective backing from both underside thermal pads. Removing only one backing prevents proper thermal contact and can leave the assembly uneven.
  3. Position the cooler above the Raspberry Pi 5. Align the heatsink with the processor area while keeping it clear of nearby board connectors.
  4. Match the two white retaining pins with the designated mounting holes in the board.
  5. Apply balanced downward pressure to both pins. Press evenly until both pins lock in place. Do not force one side down while leaving the other side unsupported.
  6. Attach the fan lead to the connector marked FAN. Ensure the plug is fully inserted and correctly oriented.
  7. Perform the post-installation check before powering the board: the cooler should sit flat, both pins should be secured, the fan plug should be fully inserted, and no case part or cable should obstruct the fan.

Installation Checklist

Power down: Remove system power before handling the board.

Remove thermal-pad backing: Expose both underside thermal pads without touching their surfaces.

Align cooler and push pins: Position the cooler over the processor and match both mounting holes.

Lock both pins: Apply balanced pressure until the two white pins engage.

Connect FAN lead: Fully insert the fan plug into the connector marked FAN.

Confirm case clearance: Check the lid, cables, GPIO accessories, and other add-ons without forcing the enclosure closed.

Removal Warning and Serviceability

Removing the cooler can weaken the push-pin retention and damage or compress the thermal pads. An attempted removal may damage the cooler, its thermal interface materials, or the Raspberry Pi board. If removal is unavoidable for service or a case change, inspect the retaining pins and pads carefully. Replace visibly degraded thermal pads or compromised mounting pins rather than reusing them.

Set Up a Controlled Thermal Test

A controlled before-and-after test is more informative than comparing two idle temperatures. Idle temperature can vary while the board is doing very little, whereas a repeatable sustained workload shows how the cooling system behaves when the processor is working continuously.

Use the same Raspberry Pi, power supply, case state, room conditions, background processes, workload, and test duration for both runs. For the fairest comparison, perform a baseline run without the cooler and then repeat it after installing the cooler. Allow the board to return to a similar idle condition between runs.

1. Install the Stress Utility

On Raspberry Pi OS, install the command-line CPU workload generator with the system package manager:

sudo apt install stress -y

If the package cannot be located, update package metadata first and repeat the installation:

sudo apt update
sudo apt install stress -y

2. Start a Four-Worker, Ten-Minute Load

Run four CPU workers for 600 seconds, or ten minutes:

stress --cpu 4 --timeout 600 &

The ampersand sends the process to the background. This allows temperature monitoring to continue in the same shell workflow or in another terminal. Four workers exercise the Raspberry Pi 5 CPU, but this synthetic workload does not behave exactly like compilation, emulation, computer vision, or a server application.

3. Monitor Temperature Every Second

In a separate terminal, or after starting the background process in the same shell, run:

watch -n 1 vcgencmd measure_temp

vcgencmd is a Raspberry Pi utility that can report board information, including SoC temperature. The command displays a new reading once per second. Press Ctrl+C to stop the display. Record the highest reading and, if useful, the temperature after the system has reached a steady state.

Example Thermal Results

In the stated comparison, the uncooled Raspberry Pi 5 reached approximately 86 degrees Celsius during the four-worker, ten-minute load. With the Active Cooler installed and the test repeated under comparable conditions, the observed temperature remained near 54 degrees Celsius.

These are test observations, not universal expected values. Results can change with room temperature, enclosure airflow, power configuration, CPU frequency behavior, workload type, background activity, and cooler installation quality. A different case or a partially obstructed fan can produce a substantially different result.

Example Thermal Test Comparison

Without Active Cooler: Four CPU workers; ten minutes; approximately 86 degrees Celsius observed under the stated test conditions. This is an example high-load baseline, not a guaranteed value.

With Active Cooler: Four CPU workers; ten minutes; approximately 54 degrees Celsius observed under comparable conditions. This illustrates the potential reduction under sustained load.

Interpretation: Compare peak and steady-state readings, while recording ambient temperature, enclosure state, power configuration, and workload details.

Fan Behavior and Verification

The fan responds to temperature rather than necessarily operating at 8,000 RPM all the time. As the processor warms, PWM can increase fan drive. This can provide cooling when needed while avoiding maximum noise during light workloads. The tachometer signal supplies rotation feedback that can help identify a stopped or failed fan.

To validate fan response, start the sustained CPU workload and observe or listen for the fan as temperature rises. A fan may be quiet or inactive at low temperature, so an idle check alone is not conclusive. If it remains inactive during a high-load test, shut down, disconnect power, and inspect the FAN plug for correct orientation and full insertion.

An observed heavy-load noise level of roughly 40 dB can be used as an indicative measurement, but it is not a guaranteed acoustic specification. Microphone distance, room noise, case design, fan speed, and measurement equipment all affect the reading.

Troubleshooting

Fan does not run under load: The plug may not be fully connected, the temperature may not have reached the fan's activation threshold, or the fan assembly may be damaged. Shut down and disconnect power, check the connector marked FAN, repeat a sustained load test, and replace the cooler if a correctly installed fan still fails.

Temperature remains unexpectedly high: A thermal-pad backing may still be attached, one push pin may not be locked, the cooler may not sit flat, airflow may be restricted by the enclosure, or the comparison conditions may differ. Power off, check both pins and the flat fit, then test outside the case to isolate enclosure airflow.

Cooler does not sit level: One pin may be only partially engaged, the cooler may be misaligned with the mounting holes, or debris may be present. Do not apply excessive force; power off and inspect the fit.

Case will not close: The enclosure may lack cooler clearance, or a cable, HAT, GPIO accessory, or other add-on may interfere. Do not force the lid. Re-route cables or select a compatible case.

Temperature test is inconsistent: Ambient temperature, background workloads, case state, airflow, power settings, and CPU frequency behavior may have changed. Repeat the test with controlled conditions and record peak, steady-state, and ambient readings.

Removal is requested: Avoid removal unless necessary because the pads and push-pin retention may degrade. Plan to replace affected mounting or thermal-interface parts if the cooler must be removed.

Choosing a Case and Buying the Cooler

Buy the official Raspberry Pi 5 Active Cooler from a reputable Raspberry Pi seller or distributor, and verify that the product is specifically compatible with Raspberry Pi 5. Before designing an enclosure, mount, or clearance-sensitive project, consult the official mechanical drawings and account for the cooler's height, mounting position, fan lead, and nearby connectors.

Check compatibility before combining the cooler with third-party cases, HATs, GPIO accessories, or cable-routing products. A mechanically compatible board does not guarantee that every accessory combination will provide enough airflow or physical clearance.

For related board and enclosure planning, see Review Raspberry Pi 5 and Raspberry Pi 5 Official Case.

Key Takeaways

  • The official Active Cooler is a Raspberry Pi 5-specific heatsink-and-blower assembly for sustained workloads.
  • It uses thermal pads, two white push pins, and the dedicated four-pin FAN header.
  • The fan uses temperature-managed PWM control and tachometer feedback.
  • Install it only with the board completely unpowered, and verify flat seating, locked pins, connector seating, and case clearance.
  • Use the same four-worker, ten-minute stress test and one-second temperature monitoring interval for meaningful before-and-after comparisons.
  • Approximately 86 degrees Celsius without cooling and near 54 degrees Celsius with cooling are observed example results, not guarantees for every setup.