EVEN More CO2 Blast Freezers, How A Subcooler Can Affect Compressor Capacity - Episode - 545 Audio

EVEN More CO2 Blast Freezers, How A Subcooler Can Affect Compressor Capacity - Episode - 545

Trapped Oil, Wild Suction Swings & the Subcooler That Won’t Behave | Advanced Refrigeration Podcast.

In this episode of the Advanced Refrigeration Podcast, hosts Brett Wetzel and Kevin Compass bounce from shop talk about Kevin’s four-screen setup to a blast-freezer mystery update: roughly 15 gallons of oil were found trapped in the flooded evaporator, sparking manufacturer finger-pointing and discussion of oil drain strategies, PAG oil behavior at very low temps, and why an economizer may not work without a pressure differential or pump. Kevin also recaps a brutal Alaska trip fixing coils shipped with undersized TXVs that caused high superheat and poor pull-down. The main deep dive tackles an A2L rack with a subcooler and crossover control, where a too-low suction/EPR setting drives the subcooler to short-cycle, alters vapor injection, and creates extreme, rapid suction pressure swings—making the crossover valve inconsistent and the system nearly impossible to stabilize.