Arkansas HVACR NewsMagazine January 2026

HVACR NewsMagazine January 2026

Tech News

Why Triple Evacuation and Cold Weather Evacuation Don ’ t Work Jim Bergmann

And How This Evacuation Graph Proves It

Most of us were taught that triple evacuation is the gold standard for drying a system. The logic seemed bulletproof: break the vacuum three times, push in nitrogen, pull it back down. Somehow, the moisture disappears. To prove the point, we set up a real evaporator coil and line set with a tiny amount of moisture. Here’s a real evacuation done on a 27 – 30°F day with a TruBlue vacuum rig, a Testo 552I pump, and a calibrated BluVac Pro: • We pulled the system down to 135 microns. • The system was STILL wet. • Triple evacuation didn’t help.

This evacuation graph is a perfect case study in why triple evacuation is outdated, and why hitting a deep vacuum number does NOT mean the system is dry.