Triple Evacuation

  May 1, 2014      Jeff Rosenblum


Many HVAC Techs have heard the term “triple evacuation”. What is a triple evacuation? Why do it? A triple evacuation is a very simple method of evacuating the refrigerant system. When you connect a vacuum pump to a refrigerant system you are lowering the boiling point of moisture in the system. Sometimes, you can pull a vacuum so fast that it can cause moisture in the system to crystallize and become trapped. An easy way to prevent this from happening is by performing a triple evacuation. A few things you will need are your gauges, nitrogen with regulator, vacuum pump and a micron gauge. Connect the equipment and start the vacuum pump. Allow it to pull the system down to about 4000 microns. Turn the pump off and break the vacuum with dry nitrogen. Start the pump again and pull the system down to 1500 microns. Now, break that with nitrogen. Then run the vacuum pump again and do your final pull down to 400 microns. Remember, the deeper the vacuum the better. The one tool that must be used any time you are evacuating the system is a micron gauge. Without it, we are just guessing. If you need any assistance, please feel free to call the Famous Supply HVAC Tech Support Dept.

Jeff Rosenblum 
Technical Support
15 Years Industry Experience
Cell (330) 962-2491
[email protected]