At the EX station, the purge air supply was switched on from 09:46 until 18:16 with the highest load possible, according to WP #12001. The temperature of the mechanical room and the environment was monitored periodically.
It can be concluded, that the HVAC system was able to hold a ~5 deg F temperature difference with the outside temperature. For more details, see graph.
The temperature was rising rapidly after switching on the purge air supply. Then, a big decrease can be seen - this could have 2 reasons: (i) the sunlight just went away from the front of the building, and/or (ii) the HVAC system reacted like this.
In the end, the HVAC system consolidated the temperature at 91.4 deg F.

This whole measurement was carried out as additional information for the installation of the new purge air supplies.