Air volume flow tracking, pressure dependent (AirFlTck12)

Overview

The application function "Air volume flow tracking 12, pressure-dependent control" (AirFlTck12) collaborates / is used only with pressure dependent VAV supply and extract air terminal boxes to calculate the VAV extract air damper position setpoint.

Function

Room pressurization mode
The VAV extract air damper position setpoint depends on the setting of PRMode (Room pressurization mode). PRMode can be set for Neutral, Positive, or Negative room pressure.

Damper position for transferred air
DmpPosTrnAir (Damper position for transferred air) equals the difference, in absolute value, between the supply and extract damper positions needed to maintain room pressurization. It represents the amount of air that enters (infiltration) or exits (exfiltration) a pressurized room through cracks or small openings. In a pressurized room, the extract damper position setpoint differs from supply damper position by the value of DmpPosTrnAir.

Example:

• In a negative pressure room, if DmpPosSuR (Supply air damper position room) = 60% and DmpPosTrnAir = 10%, the extract damper position setpoint (PrSpDmpPosEx) will = 70%.
• In a positive pressure room, if DmpPosSuR = 60% and DmpPosTrnAir = 10%, PrSpDmpPosEx will = 50%.

DmpPosTrnAir is a positive number regardless of PRMode value.

Configuration

Parameters