This paper investigates the performance of liquid overfeedand direct-expansion (DX) refrigeration systems and includescomponent performance and system balance. This projectincludes the design of two refrigeration circuits, liquid overfeedflooded and DX with a common condenser, and analyzes theperformance of the heat exchangers and their impact on the overallcircuit’s performance. Several design techniques and methodsare considered, including geometry and construction of heatexchangers. The performance of the two circuits is compared forfour operating temperatures; –20°C (–4°F), –10°C (14°F), 0°C(32°F), and 5°C (4°F); and analyzed to ascertain circuit operation.DX evaporators are often utilized operating at–10°C(14°F)and below for relatively small duty systems, below 25kW(7.1 TR).However, liquid overfeed flooded evaporators are rarely seenpractically for systems in this range. The performance of the DXandliquid overfeed floodedevaporatorsis alsoanalyzedfor smallduties at the four operating conditions.