This is interesting. As Adam mentioned, I checked the equations in 17.4 Air System Fans. From the equations (17.131 to 17.136), even if f_motortoair is 0, it does not imply the Q_toAir variable is 0, therefore, the enthalpy of air at the outlet is not equal to enthalpy at the inlet. (check the derived equations in image)

h_out > h_in

The psychrometric function (eq. 17.136) calculates fan outlet drybulb temperature higher than the inlet fan air temperature. Therefore even if f_motortoair = 0, there is addition of heat and T_out > T_in.

This is interesting. As Adam mentioned, I checked the equations in 17.4 Air System Fans. From the equations (17.131 to 17.136), even if f_motortoair is 0, it does not imply the Q_toAir variable is 0, therefore, the enthalpy of air at the outlet is not equal to enthalpy at the inlet. (check the derived equations in image)

h_out > h_in

The psychrometric function (eq. 17.136) calculates fan outlet drybulb temperature higher than the inlet fan air temperature. Therefore even if f_motortoair = 0, there is addition of heat and T_out > T_in.T_in

This is interesting. As Adam mentioned, I checked the equations in 17.4 Air System Fans. From the equations (17.131 to 17.136), even if f_motortoair is 0, it does not imply the Q_toAir variable is 0, therefore, the enthalpy of air at the outlet is not equal to enthalpy at the inlet. (check the derived equations in image)

h_out > h_in

The psychrometric function (eq. 17.136) calculates fan outlet drybulb temperature higher than the inlet fan air temperature. Therefore even if f_motortoair = 0, there is addition of heat and T_out > T_in

This is interesting. As Adam mentioned, I checked the equations in 17.4 Air System Fans. From the equations (17.131 to 17.136), even if f_motortoair is 0, it does not imply the Q_toAir variable is 0, therefore, the enthalpy of air at the outlet is not equal to enthalpy at the inlet. (check the derived equations in image)

h_out > h_in

The psychrometric function (eq. 17.136) calculates fan outlet drybulb temperature higher than the inlet fan air temperature. Therefore even if f_motortoair = 0, there is addition of heat and T_out > T_in