How long should a vacuum pump be operated to properly evacuate an A/C system?

To properly evacuate an A/C system, running a vacuum pump for about 30 minutes is considered ideal for several reasons. First, effective evacuation requires removing moisture and air from the system, which can contaminate the refrigerant and damage the components. The 30-minute duration allows the vacuum pump to adequately reduce the pressure in the system, thus ensuring that any moisture is evaporated, and any non-condensable gases are effectively removed.

Moreover, the time needed to achieve a deep vacuum (around 500 microns or lower) can depend on various factors, including the size of the A/C system, the pump's capacity, and the amount of moisture present. A longer evacuation period ensures that the desired vacuum level is reached, reducing the risk of future system issues.

Operating a vacuum pump for a shorter duration may not provide sufficient time to remove all contaminants, leading to poor A/C performance, possible ice formation, or other operational problems in the future. Hence, operating the vacuum pump for around 30 minutes is a best practice to ensure a thorough evacuation of the A/C system.