What may happen if refrigerant liquid is charged into a refrigeration system under a 29 inch Hg vacuum?

Charging refrigerant liquid into a refrigeration system under a 29 inch Hg vacuum can cause system water to freeze due to the significant drop in pressure. When the pressure in the system is reduced to a vacuum state (like 29 inches of mercury), the boiling point of water is lowered. Under these conditions, any moisture that might be present in the system can evaporate and subsequently freeze as the refrigerant is introduced.

This poses a risk to the refrigeration system since the presence of ice can block evaporator coils or other components, inhibit proper airflow, and lead to efficiency losses or mechanical failures. Therefore, it's critical to minimize moisture during the charging process to prevent ice formation.

The other options do not accurately reflect the consequence of charging refrigerant under such vacuum conditions.