Last month’s column introduced the concept of giving “too much control” to the building operators through the BAS graphic. I used a simple and fairly obvious example of an air handler with dual temperature set points. This month, I want to share another equally real-life example that is much more subtle.

On a VAV air-handling system, the BAS graphics included the following parameters, all of which were easily adjustable through the user interface:

  • For the central AHU

- Unoccupied setup temperature set point; and

- Unoccupied setback temperature set point.

  • For each VAV zone

- Occupied cooling temperature set point;

- Occupied heating temperature set point;

- Unoccupied setup temperature offset set point; and

- Unoccupied setback temperature offset set point.