For the first time, the impact of indoor air distributions on the thermal and power performances of single layer semi-transparent photovoltaic (SL-STPV) facades was investigated in this study. A novel two-dimensional steady-state heat transfer model for SL-STPV facades was developed and experimentally validated, which is capable to simulate the operating temperature of PV modules in non-uniform thermal environment, and then evaluate the power generation capacity as well as the heat gain of SL-STPV facades for building-integrated applications. In addition, the thermal and power performances of SL-STPV facades were numerically investigated for two typical indoor air distribution systems, named displacement ventilation (DV) and mixing ventilation (MV) systems. The results revealed that the indoor air distribution slightly influenced the average operating temperature of PV module, but greatly affected the heat gain of SL-STPV facades. The heat gain of SL-STPV facades in DV system was reduced 11.7%, in compared with that in MV system. Thus, the DV system is suggested to be adopted in buildings installed with SL-STPV facades, to achieve a better overall energy performance.