Steady-state and transient thermodynamic models of the refrigeration system were created in order to predict the performance of household refrigerators using different refrigerant types. The models were validated with experimental data taken from a commercially available household refrigerator charged with HFC-134a. The models were then used to simulate the drop-in performance of several alternative low global warming potential (GWP) refrigerants in the household refrigerator. The alternative refrigerant of strongest interest was HFO-1234yf, which was evaluated as a direct drop-in replacement for HFC-134a. HFO-1234yf was found to be a suitable replacement for HFC-134a, with similar performance characteristics and a decrease in overall system efficiency of less than 2%. A parametric study of HFC-134a/HFO-1234yf blends was also conducted in order to evaluate their potential as non-flammable, low GWP replacements for HFC-134a.