However, suction line accumulators are often employed on these systems for added protection. This will help ensure that all refrigerant entering the compressor is liquid free. This will also help keep a fully active evaporator. Lower temperature applications generally utilize lower evaporator superheats than medium- and high-temperature applications. Please consult the case and/or appliance manufacturer if in doubt. (In the absence of manufacturer’s data, the chart on page 17 shows guidelines for evaporator superheat settings.)
There will always be a time when the evaporator sees a light load and the TXV may lose control of its evaporator superheat due to limitations of the valve and to system instability. This is where total superheat comes into play.