For the creation of livable indoor environments, ventilation strategies are widely implemented. When utilizing ventilation methods to attain thermal comfort indoors, the ventilation performance index related to thermal comfort holds significant importance. Air temperature, air velocity, and relative humidity are the three critical environmental air parameters of ventilation methods that affect thermal comfort. Nevertheless, the existing ventilation performance indices, namely the Effective Draft Temperature (EDT) and Effective Moisture Temperature (EMT), cannot simultaneously incorporate these three parameters for thermal comfort assessment. This chapter introduces a new ventilation performance index, the Effective Draft–Moisture Temperature (EDMT), which is designed to consider the aforementioned three environmental air parameters concurrently for evaluating thermal comfort. The EDMT is proposed based on the equivalent transfer of the thermal comfort effects of air velocity and relative humidity to air temperature. Two algorithms of cascaded equivalent thermal comfort transfers are developed. Using these algorithms, the EDMT is quantified and tabulated, providing practical convenience for diverse thermal comfort requirements during cooling and heating operations. The outcomes of Monte Carlo simulations and the analysis of ASHRAE Thermal Comfort Database II reveal that the thermal comfort evaluation accuracies of the EDT and EMT are 88.7%–95.5% and 70.9%–89.0%, respectively. In contrast, the accuracies of the proposed EDMTs for Algorithm 1 and Algorithm 2 are 97.3%–99.3% and 97.7%–99.3%, respectively. The proposed EDMTs of Algorithm 1 and Algorithm 2 are reliable and practical for real-world applications.