What CFM (displacement) vacuum pump should I choose?

Match displacement to system volume: 4–6 CFM (about 7–10 m³/h) is fine for splits and small systems; 8–12 CFM suits larger commercial systems and long line sets. Higher CFM shortens the time to reach vacuum, but the ultimate vacuum level depends on the number of stages, not on displacement.

Single-stage or two-stage pump?

A two-stage pump reaches a deeper ultimate vacuum (typically below 15–25 microns) and is the HVAC/R standard, especially for moisture-sensitive R410A and A2L refrigerants. Single-stage is only adequate for simple jobs that don't require a deep vacuum.

Is the pump suitable for A2L refrigerants (R32, R454B)?

For A2L systems use a pump rated for flammable refrigerants — with a spark-free motor or manufacturer-approved for A2L. Always purge the system with nitrogen (OFN) beforehand and check the F-gas requirements for the refrigerant in question.

Vacuum pumps

How to get moisture and air out of the system before charging with refrigerant — vacuum pumps for evacuating refrigeration, AC, and heat pump systems.

Genuine brands

About this category: Vacuum pumps

A vacuum pump pulls a deep vacuum on the system, boiling off moisture and removing non-condensable gases before the refrigerant charge. Evacuating below 500 microns (µmHg) and holding that level in a decay test prevents expansion-valve freeze-up, oil-moisture reactions and loss of capacity. Two-stage pumps reach a far deeper vacuum than single-stage units and are the standard for servicing R32, R410A and A2L systems.

Choose by displacement (CFM or m³/h) matched to the system volume — larger systems and longer line sets need higher CFM to keep evacuation time reasonable. Check the number of stages (two-stage = lower ultimate vacuum), the ultimate vacuum rating in microns, a gas-ballast valve to purge moisture, and A2L compatibility (spark-free motor / suitable construction). Round out the kit with a micron vacuum gauge, valves with 1/4" and 3/8" connections and good-quality pump oil.

Frequently asked questions