VAV controls: don’t fly blind

The classic setup: a 0-10 V setpoint signal to the damper, a 0-10 V flow feedback signal for control. It works. But that’s all it does.

When the VAV box communicates over a bus, you get access to much more: Min/Max thresholds, the actual position of each damper, and the ability to change parameters remotely.

At commissioning, the gain is immediate. No need to walk to each damper one by one to check or correct a setting. Everything can be read and adjusted from the controls.

For network optimization, actual position is the key data point. In most installations, pressure is set too high: every damper throttles, and the fan overconsumes. The right method: the most demanding damper — the one struggling hardest to reach its target flow — should sit between 90% and 95% open. Set pressure accordingly, and the rest follow naturally.

Without bus feedback, you don’t know where each damper actually stands. You’re flying blind. You’re wasting energy.

Have a project with communicating VAV boxes? Let’s talk.