When evacuating a system, what is the minimum microns that the vacuum pump must pull?

When evacuating a refrigeration or air conditioning system, it is essential to achieve a sufficiently deep vacuum to ensure that all moisture, air, and contaminants are removed from the system. The industry standard for a deep vacuum is typically around 500 microns, which is considered a safe minimum for proper evacuation.

At this level, you begin to ensure that the water vapor and other non-condensable gases have been adequately removed. Pulling a vacuum to 500 microns helps in achieving proper refrigerant charging, system efficiency, and longevity of the equipment.

If a vacuum higher than this—such as 600 or 700 microns—is achieved, it may indicate that there are still impurities present in the system, potentially leading to issues like corrosion or inefficiency after the refrigeration cycle begins. Therefore, aiming for a vacuum of 500 microns is critical for effective system operation.