Bubba and I are making progress understanding the control logic (and illogic?) of our VEA control loops. We have turned on heaters in all three VEA/LVEA areas in order to compensate for the cold front.

Provided we have made sensible changes to the system we should see things stabilizing overnight.

One mechanical problem found was an outside air damper at Y END which was not able to close - therefore admitting a significant amount of cold outside air. We did not have a similar problem at X END where the excursion was much less pronounced.

Hopefully this mechanical fix and some parameter changes will settle things.