Air Conditioning Repair Certification (ETI) Practice Exam

The process of latent heat transfer involves the absorption or release of heat without a change in temperature. This typically occurs during phase changes in a substance, such as when water evaporates to form steam or when steam condenses back to water. During these transitions, the energy is used to alter the state of the substance rather than to increase its temperature.

In the case of water, for instance, while the temperature remains constant at 100 degrees Celsius during boiling (the phase change from liquid to gas), latent heat is required to convert the liquid into vapor. Similarly, when vapor condenses back into liquid at the same temperature, latent heat is released. This concept is essential in understanding various processes in air conditioning and heating systems, where phase changes play a critical role in how energy is managed.

This distinction is what makes latent heat the correct answer to the question about heat transfer with no change in temperature, as opposed to the other options provided, which involve changes in temperature or specific types of heat transfer that are not related to phase changes.