For the wetheads here.
1) Besides sending off for a chemical analysis,how can you determine if you are testing Ethylene or Propelyne? I have a freeze point indicated on the spec of 17 for ethylene and 21 for prop, both correspond to a lower concentration than the work order calls for. It is almost clear with a slight blueish tint, and I know the spcs called for ethelyne. We want 30 percent, but either way, I am looking at about 19 or 20 percent. I suppose that my only effect would be more chiller than needed.
2) The system has a volume tank installed due to perceived short loop syndrome, however I have only one coil and one threeway valve on this loop and wonder if a "mixing" tank is needed as per the Application info I pulled on the unit. Please explain the mixing tank theory.