The methods to control thermal energy generated by Intel® Joule™ compute module fall in to three broad categories: passive cooling, active cooling, and firmware controls.
Passive heat dissipation or cooling involves either the convection of heat directly from the module’s thermal plate to the environment (only appropriate for very low power applications), or the conduction of heat from the thermal plate to a passive heatsink.
- Passive cooling solutions that rely solely on the module thermal plate are limited to applications where SoC power stays below 1.5 W at 25 °C ambient temperature.
- Solutions that include a passive heatsink acting as a heat exchanger between the module and the ambient environment can typically dissipate 2 W to 3 W at 25 °C ambient temperature.
- The highest performing passive designs will achieve up to 5 W of dissipation at 25 °C ambient temperature.
Active cooling is the addition of a fan or blower to a passively cooled solution in order to force air to flow through a heatsink. Active cooling solutions can scale up to 8 W and beyond.
|Thermal Control Method||Maximum Power Dissipated (W) at 25° C|
|Passive cooling (thermal plate only)||1.5|
|Passive cooling (typical heatsink)||3|
|Passive cooling (high performance)||5|
Firmware controls are configured in BIOS and function independently of any active or passive cooling, or software (OS) based thermal control loops. Two BIOS settings allow system designers to define both a static power limit for the module and maximum temperature limit. The two controls work in concert to maintain module operation within a set temperature range, but incur a system performance tradeoff. See Firmware Controls for more information on the temperature control and power limit BIOS settings.
Heatsinks and Fans
- Very low power workloads (<1.5 W) can transfer thermal energy directly into their environment via the module’s thermal plate.
- Low to moderate workloads (1.5 W to 3 W) will require a larger surface area to dissipate heat
- Enclosures and heatsinks can be designed to encourage thermal convection (natural airflow) in moderate
- A powered fan can provide constant airflow across the thermal plate or heatsink.
- Module power can be varied to maintain module within an ideal thermal range.
See also Heatsink Options for additional information.