Tonight is the first of a three night shift retrofitting some ancient Hussman racks to R-449a. In Canada R-449a is one of only a small number of new zeotropic blends that meet GWP standards. We'll use a push pull method to recoup the gas with the rack running. A team on the floor will close TXVs to prevent any unwanted liquid return, and they'll replace caps and shraeder cores in the suction line access. By tomorrow morning the system will be flowing and a day team can come and adjust superheats an make any final modifactions. On the low temp rack we've already installed Demand Cooling modules. An oil change will be in order as well.

Posted by Deleted (4a569f68) at 2021-02-16 01:11:10 UTC