This is a story about two new construction commissioning projects with similar challenges and as-yet unwritten endings.
The first project is one in which the commissioning professional was engaged before the schematic design phase, and the project is currently early in construction. The design engineers did not develop a detailed set of control sequences during the design phase. This was despite repeated requests from the commissioning professional for more information regarding the intended operation of the HVAC systems through multiple design review cycles.
The design engineers’ corporate standard for control system design was to provide a points list along with a brief description of what some (not even all) of the systems should do. For example:
- The boiler system shall deliver hot water to all terminal units;
- The heat recovery ventilator shall precondition the outside air;
- The AHU shall maintain a set point building pressure; and
- The unit heater shall maintain a set point space temperature.
They believed the controls contractor should be given latitude with respect to how the systems achieve these high-level performance goals. The project is currently awaiting the controls contractor’s submittal package.