When should blended refrigerants be charged into a running system?

Charging blended refrigerants should be performed as a liquid through a throttling valve into the low side because this method maintains the refrigerant’s composition and prevents separation of its components. Blended refrigerants are made up of two or more different refrigerants; if charged as a vapor into any part of the system, there is a risk that the different components might separate based on their varying boiling points, which can lead to inefficiencies and operational issues within the system.

When charging into the low side, using a throttling valve allows the liquid refrigerant to evaporate and absorb heat within the evaporator, which is crucial for the effective cooling operation of the refrigeration system. This helps maintain the intended thermodynamic properties of the blend, ensuring efficient operation and optimal performance of the system.

In contrast, charging as a vapor might not adequately facilitate the proper mixing of the components within the refrigerant and could lead to imbalances in performance. Charging as a liquid into the high side could also create excessive pressure and potential damage to the high side components. Thus, conducting the charge as a liquid into the low side via a throttling valve is the most effective and safe method for handling blended refrigerants.