What is the term used for a substance changing from a solid to a gas?

The term used for the process of a substance changing from a solid to a gas is indeed referred to as the latent heat of sublimation. This term specifically describes the energy required to convert a solid directly into a gas without passing through the liquid phase. During sublimation, the molecules of the solid gain enough energy to break free from their fixed positions in the solid structure and enter the gaseous phase.

Understanding this concept is important in refrigeration and HVAC systems, as it relates to how materials behave at different temperatures and pressures. For example, ice (solid water) can sublimate to water vapor under certain conditions, which is significant for applications involving phase changes in refrigeration cycles.

The other terms refer to different phase changes: the latent heat of fusion pertains to the transition from solid to liquid, the latent heat of condensation refers to the change from gas to liquid, and the latent heat of vaporization applies to the process of converting a liquid to gas. Each of these processes involves different energy changes and is critical in understanding thermodynamic principles in refrigeration.