a recent article from electronics cooling, written by technology consultant rick slagle of technical solutions marketing, describes how the process of vapor-compression cooling, which is common in air conditioners and refrigeration, actually works.

the article and video show how vapor-compression cooling works.
(aspen systems/youtube)

the process was originally invented in 1805 and the first vapor-compression refrigeration system was built in 1834 but it is a process that many still do not fully understand.

slagle wrote, “vapor-compression cycle refrigeration is a process that uses the physics of phase change heat transfer and the unique properties of a refrigerant to transfer heat from a relatively cold source to a hot medium. simply stated, refrigeration systems efficiently move heat from a cold source to a hot heat sink (normally air).”

the key to the system is the compressor, which take in low-temperature, low-pressure vapor and compresses it before sending it to the condenser where the heat is removed to air or water. the removal of the heat releases energy stored in the now high-pressure gas and the refrigerant becomes a hot liquid.

“this hot, high temperature liquid then exits the condenser and enters the expansion valve, where it undergoes a pressure drop causing some of the hot gas to vaporize,” the article continued. “this lowers the temperature of the refrigerant stream. the refrigerant at the exit of the expansion valve is a low temperature two-phase fluid.”

the two-phase liquid enters an evaporator, is exposed to a heat source, and the refrigerant is boiled off into vapor that enters the compressor again.

“the vapor compression cycle can be used to cool air, liquid, or cold plates,” slagle wrote. “all that is required to accomplish this is to modify the evaporator to accommodate the systems that are being cooled.”

learn more about this subject by watching the video from aspen systems below: