Refrigerants and other multi-phase systems

The pysch chart represents one example of a multi-phase system (air with different levels of water saturation). Others include steam and various refrigerants. In commercial HVAC, steam and refrigerants constantly cycle through states to address loads.

[eileenwestervelt]

Psychometrics, steam systems and refrigeration systems have saturated processes where phase change occurs, but all parts of the system are not at saturation.

[eileenwestervelt]

A more accurate description of the phase of the water vapor in interior building air is as a superheated gas, not a liquid.