What is the refrigerant state of ammonia at -30°F and 6" Hg?

At a temperature of -30°F and a pressure of 6 inHg, ammonia can exist in a specific state based on its temperature and pressure characteristics.

To determine if the refrigerant is superheated, saturated, or sub-cooled, we first need to understand the behavior of ammonia under varying pressures and temperatures. Ammonia behaves differently based on its thermodynamic properties, and at the given low pressure (6 inHg), the saturation temperature for ammonia is significantly lower than -30°F. In this scenario, -30°F is above the saturation temperature, which means any ammonia present in this state would be in the superheated region.

Superheated refrigerants are those that have been heated beyond their saturation temperature at the given pressure, implying that they do not condense into a liquid yet despite being at a pressure that could otherwise allow boiling. Therefore, in this particular condition with ammonia, it is indeed superheated because it is at a temperature significantly higher than the corresponding saturation temperature for its current pressure.

This analysis clarifies that the refrigerant is not saturated since that state would require a balance between liquid and vapor phases at a specific pressure and temperature, which is not the case here. Likewise, it cannot be classified as sub-cooled, as