Heat Pipes

Since its beginning in the early 1960s, the heat pipe technology has evolved into many different shapes and forms and has been used in numerous applications from computer cooling to spacecraft thermal control. The following pages contain information on our experience with various advanced forms of heat pipes:

Heat Pipes for Thermal Management

Advanced Cooling Technologies is a leader in heat pipe products and technologies. ACT grew as a heat pipe company before adding thermal expertise across all thermal platforms. Nevertheless, today ACT is still manufacturing large quantities of heat pipes and heat pipe assemblies for a wide range of applications. In addition, ACT is a leader in developing new functionality and increased performance with emerging heat pipe technology.

Heat pipes are used across a wide range of markets and applications. ACT is the only US manufacturer that routinely delivers heat pipes for terrestrial electronics cooling (copper-water), on orbit satellite thermal management (aluminum-ammonia) and high temperature calibration equipment (liquid metal heat pipes). Navigate through the products section for more information on any of these highly reliable products.

If you are designing a thermal system and simply want to learn more about heat pipes, use the links in the Operation Section. If you still have questions- contact us, and an engineer will be in contact with you.

Constant Conductance Heat Pipes (CCHPs), are the most basic type of heat pipe.  Heat is transferred by the evaporation and condensation of a working fluid:

curved heat pipes

Heat transfer to the evaporator vaporizes liquid within the wick.
  • Vapor pressure drives fluid to the condenser
  • Heat transfer from the condenser condenses vapor at the wick.
  • Liquid returns to the evaporator by capillary forces generated in the wick
The benefits of a standard heat pipe include:
  • High Thermal Conductivity (10,000 to 100,000 W/m K)
  • Isothermal
  • Passive
  • Low Cost
  • Shock/Vibration tolerant

See a full video and transcription about the basics of heat pipes and their advantages.


Product Links

  • Copper (Cu) Heat Pipes

    For most terrestrial applications Cu-H2O and Cu-Methanol are used.

  • Aerospace Heat Pipes

    Learn more about aluminum-ammonia heat pipes used for spacecraft thermal control.

  • High Temp Heat Pipes

    using liquid metal as the working fluid allows heat pipes to operate up to 1,000 degrees C.

  • HVAC / Energy Recovery

    Wrap around heat pipe heat exchangers create efficient operation to lower operating costs by pre-cooling incoming air.


  • How do heat pipes work?

    Background physics to heat pipe operation including video that demonstrated the two-phase heat transport.

  • Heat Pipe Gallery

    CCHPs VCHPs Loop Heat Pipes heat Pipe Loops Vapor Chambers ACT Heat Pipe Gallery

  • Heat Pipe Performance

    The amount of power (W) a heat pipe can move is determined by several variables. Learn about the various heat pipe limits that govern overall performance.

  • Heat Pipe Calculator

    Use this tool to calculate a heat pipe's capability for your system. Works for copper-water heat pipes.

  • Design Guide

    Learn the basics on how to size and model your heat pipes with our heat pipe design guide. You'll be able to integrate heat pipes into your project in no time!

  • Wick Structures

    Learn about the advantages, limitations, and trade-offs of various wick structures.

  • Fluid Selection / Compatability

    Heat pipe fluids are determined primarily by the ambient conditions and thermodynamic properties of the fluid.

  • Different Types of Heat Pipes

    In addition to the standard, Constant Conductance Heat Pipe (CCHP), there are a number of specialized heat pipes.

History and New Advancements

  • Heat Pipe History

    Go back to 1963 when the heat pipe was discovered and view how heat pipe applications have expanded since.

  • Technologies

    Over the years ACT has developed many heat pipe related technologies for future applications.