Research studies indicate that indoor temperature has different effects on people's psychology and work productivity in different regions, and there is a potential for building energy conservation. This study aims to research the balance between thermal comfort, productivity, and energy conservation of air-conditioning systems in office buildings in Taiwan. Such understanding can provide detailed control logic of air-conditioning systems for energy-saving in office buildings. An experimental study was conducted in a climate chamber. A total of 948 thermal and productivity responses were obtained from the questionnaire survey and Vienna test system. The 80% satisfaction interval and 20% Predicted Percentage of Dissatisfied (PPD) were also applied to explore the greater acceptable temperature range and energy-saving potential of the air conditioning system. Data analysis revealed that in Taiwan, the neutral temperature of the thermal sensation vote (TSV) was 26.8 °C, and the Predicted Mean Vote (PMV) value was +0.84. The optimum temperature of the subjects was 26.2 °C, and the PMV value was +0.69. The 80% satisfaction interval of thermal comfort vote (TCV) was between 25.4 °C and 27.4 °C. Meanwhile, the optimum temperature to achieve the best productivity was 27 °C for men and 25 °C for women. Finally, three control logics were proposed for air-conditioned indoor environments in subtropical regions. The energy consumption gaps between control logics and different international benchmarks were compared through the office model of EnergyPlus. As a result, the air-conditioning system based on thermal comfort control can achieve 9.1% energy-saving potential.