What is an air conditioner vacuum pump?

An air conditioner vacuum pump is a pump used to remove moisture from refrigerant lines. Moisture enters an air conditioner during installation and must be removed before the air conditioner is used. If the lines are not vacuumed, the air conditioner can not work efficiently.

When moisture enters an air conditioner's refrigerant lines, it can combine with the refrigerant and begin to freeze, potentially blocking the lines. Moisture in the lines can also corrode metal. If water mixes with the oil in an air conditioner's refrigerant, a condition known as sludging occurs. Sludging decreases the ability of the oil to lubricate parts and can result in the air conditioner breaking down.