In the present study the structure of an Alpha-type Stirling engine is designed which is capable of operating in reasonable operating condition ranges. The Alpha-type Stirling engine is simulated by GT-Suit program and the Solo V161 experimental data are used to validate the numerical model. The structure of the engine is kept constant and operating parameters such as, pressure, engine speed, temperature of the heater and working fluid are changed for using in a sample residential building in different climates. The engine is used for combined production of cooling, heating and power in micro scale (micro-CCHP). Three methods including following electrical load (FEL), following thermal load (FTL) and overall efficiency of the cycle are used for engine sizing. The maximum overall efficiency of the micro-CCHP ranges from 79% to 88% in different climates. The results show that both FEL and overall efficiency propose the same engine size and the highest overall efficiency for every climate. Furthermore, the reduction of environmental pollutants of CO2, CO, and NOx are calculated. The maximum CO2 reduction for every climate is more than 40%. In addition, leaking that usually occurs in this type of engine is lowered by operating at considerably lower pressure.
