def enthalpy_from_db_hr(db_temp, humid_ratio):
enthalpy = ((<NUM_LIT> + (<NUM_LIT> * humid_ratio)) * db_temp) + (<NUM_LIT> * humid_ratio)<EOL>return enthalpy if enthalpy >= <NUM_LIT:0> else <NUM_LIT:0><EOL>
Enthalpy (kJ/kg) at humid_ratio (kg water/kg air) and at db_temp (C).

    Note:
        [1] Vaisala. (2013) Humidity Conversion Formulas:
        Calculation Formulas for Humidity.
        www.vaisala.com/Vaisala%20Documents/Application%20notes/Humidity_Conversion_Formulas_B210973EN-F.pdf