Refrigerant Evacuation

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  • Proper evacuation techniques save time & money.
  • Using the right equipment is crucial & inexpensive!
  • Vacuum rated hoses and valve core removal tools are a no brainer.
  • Larger diameter hoses reduce recovery time.


Pulling a proper evacuation can be one of the most time consuming portions of any R-22 conversion, but it’s vital to ensure that the system is clean and leak-free. Not pulling a proper vacuum will ultimately reduce the life of the equipment in a variety of ways.

Many technicians simply give up on pulling a proper vacuum due to past difficulties that are largely due to improper equipment and/or techniques. A few simple steps can greatly reduce evacuation times and reduce call backs.

Best Practices

  • Always use vacuum rated hoses (generally black).
  • Always use valve core removal tools to remove Schrader cores and isolate system for standing test.
  • Minimize connections as much as possible and test vacuum equipment prior to evacuation.
  • If system doesn’t pull down quickly, a triple evac may help remove moisture and reduce evac time.
  • Cold ambient conditions can greatly increase evacuation times, plan accordingly.

Additional Tips

  • Large diameter hoses provide more “bang for your buck” than large CFM vacuum pumps.
  • Two smaller pumps on opposite sides of the system are better than one large pump.
  • General rule is if rated CFM squared is less than system tonnage, vacuum pump is sufficient size. Example: (10 CFM)2 = up to 100 Tons.


Figure 1. Appion MegaFlow hose and valve core removal tool.