Generative AI and EV Batteries: Why Liquid Cooling?

Advancing technologies like high-performance artificial intelligence (AI) and electric vehicle (EV) batteries use more power. More power generates more waste heat, so much so that generative AI and EV battery innovators are shifting to liquid cooling. We'll explore why liquid cooling is a fundamental part of this conversation. 

Heat Capacity of Air versus Liquid  

 At the most basic level, liquid cooling has a higher capacity (C_p) to absorb heat than air cooling. Heat capacity measures how much energy (Joules) it takes to increase a mass (grams) to a specific temperature (Kelvin/Celsius). At room temperature:

Water absorbs 4 times as much energy as air to increase the same temperature. 

C_p air = 1.0035 J/gK

C_p water = 4.1813 J/gK

C_p ethylene glycol = 2.36 J/gK

C_p propylene glycol = 2.5 J/gK

Higher heat capacity = more efficient, higher capacity cooling.

The density of Air versus Liquids  

Liquids are much denser than air. Higher density means there is more liquid mass in a defined volume than there would be air mass. Comparing the density (ρ) of air versus water, water's density is magnitudes higher than air.

Water has 829 times the mass of air in the same space! Another way to look at it, you would need 829 cm³ of air to weigh the same as 1 cm³ of water. That's like a game of dice weighing the same as 9 12-ounce aluminum cans.

Density Air = 0.001204 g/cm³

Density Water = 0.9982067 g/cm³

^{Greater density = more cooling capacity in a defined space.}

^{Higher Heat Capacity and Density Work Together}

Liquid cooling's edge doesn't come from its high heat capacity or density independently. Combining these two properties makes the liquid a powerful cooling solution.

Most applications are restricted by how much space is available for cooling. Here's an example:
We'll hold the volume constant to compare; Assume we have 100cm³ for simplicity.

In 100cm³, we can have either 0.12g of air or 99.8 g of water.

0.12g of air can absorb 0.12 Joules of energy before it increases by 1 degree Celsius

99.8g of water can absorb 417 Joules of energy before it increases by 1 degree Celsius

That's over 3000 times more heat absorbed in the same volume.

The liquid absorbs more than 3000 times the heat from generative AI chips and EV batteries in the same space as air.

^{Why isn't Liquid Cooling used for Everything?}

Liquid cooling can cool more and faster than air but it comes with its own challenges. Air is easily available. Air only requires fans, blowers, ducting, or air baffling to control flow. The liquid is not readily and abundantly available everywhere. Liquid cooling requires tubes, manifolds, pumps, and fittings to circulate liquid. Liquid presents leak and water damage risk that is preventable with smart sensors, software, and system redundancies, but this adds to infrastructure complexity. High density also means the liquid is more difficult to move compared to air. Liquid systems either move slower or require more powerful pumping systems.

Innovators in generative AI and EV batteries turn to liquid cooling when thermal demands surpass what is feasible with air cooling. The need for higher performance outweighs Liquid's additional system and infrastructure complexities.

^{Picking the Right Cooling System for your Application with BOYD}  

Boyd has decades of high-reliability liquid cooling system field performance in regulated and high-safety critical markets. We have dependably cooled high power loads by refining liquid system design to mitigate liquid cooling system challenges while maximizing its high cooling capacity benefits. Innovators in generative AI and EV batteries who are pushing their performance boundaries, and by default their thermal management system boundaries, are turning to Boyd for liquid cooling concepts, advanced component and system design, thermal simulation and modeling, cooling innovation, global manufacturing at scale, and 100% in-line leak testing.  

Boyd is an invaluable liquid cooling partner with thermal management expertise across the whole air and liquid cooling spectrum to help push the limits of air-cooled solutions or safely introduce liquid systems. We're cooling the most advanced generative AI and EV battery applications in the market today with advanced, high-efficiency, dependable liquid cooling systems. Contact us to discover how we can help cool your AI and EV battery systems.