Passive Cooling vs. Active Cooling | Diabatix

August 10, 2023
Sarah da Silva Andrade

Today, we will explain how thermal design works for Passive Cooling and Active Cooling systems. We will also talk about our software, ColdStream, which is changing how these two strategies are used.

Understanding the Fundamentals: Passive vs. Active Cooling

The world of thermal design orbits around two central principles: Passive Cooling and Active Cooling. While they both aim to achieve the same goal of temperature regulation, they diverge significantly in their methodologies and applications.

Passive Cooling: A Symphony of Natural Processes

Passive cooling is like a symphony of natural heat dissipation processes. This method incorporates inherent thermal management properties of materials and tackles natural phenomena like conduction, convection, and radiation to regulate temperatures.

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Conduction, the first player in this symphony, is the transfer of heat between substances in direct contact. Different materials have varying conductive properties, and this method of heat transfer is most effective in solid and dense materials. By strategically selecting materials with optimal conductive properties, passive cooling systems can maximize heat transfer.


Convection, the second player, involves heat transfer by the movement of fluids or gases. This principle enables the circulation of cooler air or liquid over the surface of a component, thus facilitating heat dissipation.


The final player in the passive cooling orchestra, radiation, involves heat transfer in the form of electromagnetic waves. All bodies at a temperature above absolute zero emit thermal radiation. Passive cooling systems take advantage of this phenomenon to emit excess heat into the surroundings.

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Passive cooling systems, through the synchrony of these three natural processes, effectively eliminate the need for external devices or energy sources. They are often known for their reliability, silent operation, and minimal maintenance costs.

Active Cooling: The Power of External Forces

While passive cooling dances to the tune of nature, active cooling takes matters into its own hands. This system actively employs external devices such as fans, pumps, or coolers to manipulate and control the thermal environment.

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Fans and blowers move air across surfaces to increase the rate of heat transfer through forced convection. In the case of liquid cooling systems, pumps are used to circulate coolant fluids that absorb and carry away heat.

Computer-related examples include CPU air coolers and liquid CPU coolers for computers, GPU coolers for graphics cards, laptop cooling pads with built-in fans, and custom liquid cooling setups for high-performance PCs.

Although active cooling systems generally consume more energy, they are often the system of choice for scenarios with high heat loads or where precise temperature control is required.

Exploring the ColdStream Effect in Thermal Design

Diabatix ColdStream is redefining the field of thermal design through its generative design and AI capabilities. It allows engineers to explore, iterate, and optimize both passive and active cooling strategies in ways never before possible.

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With ColdStream, passive cooling is reimagined through the lens of innovative design to maximize natural heat dissipation. Active cooling is also elevated, with precise modeling of complex heat flows, facilitating the design of efficient cooling components for high-performance systems.

By offering unparalleled design flexibility and optimization, ColdStream allows engineers to explore a spectrum of possibilities and devise the perfect cooling strategy tailored to each scenario.

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