Thermosiphons Efficiently and Reliably Transport Heat

Why Use A Thermosiphon?

Thermosiphons operate on the same principles as heat pipes; energy is absorbed into the system where liquid is turned into vapor, vapor is transported by using the pressure difference between hot and cold regions, and rejected out of the system as the vapor is condensed back into a liquid. Low overall temperature drops enable isothermal cooling over large surfaces or across multiple devices.

Air-to-Air Loop Thermosiphon

By integrating thermosiphon technology into heat exchangers, Boyd enables cost and weight savings by negating the use of a wicking structure. By utilizing gravity for reliable passive two-phase cooling, Boyd enhances heat exchangers for improved thermal transfer.

Direct Contact Loop Thermosiphon

Thermosiphons can work as efficient, cost saving heat pipes as they function very similarly but have no wicking structure. If they are designed properly to utilize gravity for the evaporation cycle of the two-phase cooling loop, engineers can negate the need for materials and assembly costs associated with manufacturing a wicking structure.

2D Thermosiphon Fin

By designing and manufacturing thermosiphons in a more planar geometry they can be used as fins for a bonded heat sink or even a thermally integrated enclosure. Although they do not offer as much design flexibility as vapor chamber fins, they can offer improved performance in compact systems.

3D Direct Contact Loop Thermosiphon


Increased Processing Power

Isothermal heat transport enables similar temperatures over large surfaces or across multiple devices, allowing processors to operate at the same high speeds.


Reliable Performance

Passive two phase heat transports enables product designers to remove pumps from the system.


Cool large heat loads remotely

Transport heat to remote regions where there is cooler or more abundant airflow.

What is a Thermosiphon?

Cost-efficient Thermosiphons

Thermosiphons offer more cost-efficient two phase cooling than heat pipes or vapor chambers, but as they are wickless, they need a consistent gravitational pull to operate. For additional cost savings, Boyd offers advanced engineering and streamlined manufacturing that enables one shot brazing.

Boyd has also developed loop thermosiphon solutions that offer passive liquid cooling for more reliable high-power cooling.

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