Simscape 2P Condenser: Fluid Temp lower than ambient air

I'm attempting to simulate a thermosiphon in Simulink using a 2P Condenser operating in ambient, moist air at 20 C. I've had a lot of problems with the simulation's initial values converging, but I think I've been able to knock those out by adjusting the reservoir properties downstream to atmospheric temperature and pressure water.

The problem I am having is that the outlet temperature of the condenser is somehow coming back to me lower than the ambient temperature of the cooling air flowing in. It's always been slightly lower by about 1 or 2 degrees. For 80 C water vapour (quality 1) entering the heat exchanger, the temperature of the liquid (quality 0) leaving the condenser is 18.92 C. Why is this occurring? Clearly, it isn't physical--what in the model is breaking?

I have attached the simulink file and a photo of the T_out scope and the model as it appears after the simulation has completed.

I am not very familiar with Simulink, so please be thorough with your explanations. Thanks!

[nick]

Hi Jack,

Kindly share the MAT file that includes the variables used in the Simulink file to reproduce the issue.