We are all taught the proper TXV superheat settings, but it is important to remember that these are the superheats to be expected when the refrigerated space is at design temperature.

Unfortunately, when we get there, the space is above design temperature. That's why they called us. We should expect the superheat to be a little higher, but how much higher?

Maybe Prof Sporlan can help us with this. Is there a chart somewhere or a rule of thumb that we can use to judge whether the superheat setting is somewhere in the ballpark if the space temperature is above design temp?