IDTechEx Asks if Single-Phase Cooling is More Favorable than Two-Phase Cooling i… – Press Release

BOSTON, July 19, 2023 /PRNewswire/ — With the continuous increase in the thermal design power (TDP) of chips, traditional air-cooling methods are struggling to meet the cooling requirements of modern hyperscale data centers. As a result, liquid cooling has emerged as a promising solution due to the high specific heat capacity of liquids.

Liquid cooling can be categorized into two main types: single-phase liquid cooling and two-phase liquid cooling. The distinction between these two lies in whether a phase change occurs during the cooling process. Two-phase cooling, while offering higher cooling capacity, also presents several challenges, such as higher costs and regulatory concerns, according to IDTechEx’s analysis.

Two-phase coolants are commonly used in both immersion cooling, where the entire electronic component is submerged in the coolant, and direct-to-chip cooling, where the coolant is brought in direct contact with the chip.


Single and Two-Phase Cold Plate

In single-phase cold plate cooling, a coolant such as water glycol is used, which is circulated inside the cold plate by coolant distribution units (CDUs). The coolant absorbs heat through convection as it passes over the heat sources (e.g., GPUs). On the other hand, two-phase cold plates or evaporators utilize dielectric refrigerants with low boiling temperatures. In two-phase cooling, heat absorption primarily occurs through the latent heat during the phase change of the refrigerant. Unlike single-phase cooling, two-phase cold plates do not rely on pumps and CDUs for circulation but instead use temperature-controlled self-regulation, resulting in easier maintenance due to the absence of moving components.

Additionally, most two-phase coolants are non-corrosive, allowing for a wider range of material selection for rack manifold and cold plate housing and reducing maintenance requirements. However, it is important to note that some two-phase refrigerants contain organic fluoro components, which raises…