We are close to the Twin Cities in Minnesota, have 34SG, 50% glycol in the combined LT and HT circuits. We are derated due to the cooling water circuit having the glycol. When it gets much above 90F we have to derate due to the fact that the radiator’s cant get rid of the heat in the cooling water circuit. Lube oil temps increase into the alarm point. We also add corrosion inhibitor.