Dump zone|Area used as a point bypass unneeded supply air from a zoning system. The dump system is typically in the conditioned space, but not an area where maintaining the space temperature at a particular setpoint is required.
Polling|A network communications arrangement where a VVT system seeks information and needs from individual zones, determines what demands have priority, and then responds accordingly. 
Pressure-dependent operation|A VVT-system approach where dampers are positioned based on demand only, or operate in two positions.
Pressure-independent operation|A VVT-system approach where dampers are positioned by demand and by the actual volume of air flowing through the damper.
Refnet joints|Engineered joints used as connection points in a VRF-system refrigerant network. Refnet joints connect the main refrigerant lines to branch runs or to indoor units.