Summertime temperatures - Additional Air Changes vs Fixed Temperature Air

I understand that the Additional Air Changes section is providing fresh air at a fixed ACH based on the selected outside conditions.

I'm curious as to why when I set the Fixed Temperature Air section to the same temperature and RH as the outside conditions, and same ACH rate they come out with different results e.g. the additional air changes comes out with a much higher room temp.

There's obviously a difference in how this is calculated, so could anyone confirm the difference between these (even when the air temp and RH for the fixed temp air is the same as the outdoor air max conditions).