.Buildings.Obsolete.Controls.OBC.ASHRAE.G36_PR1.AHUs.SingleZone.VAV.SetPoints.ExhaustDamper

Information

Control sequence for exhaust dampers without fans. It is implemented according to ASHRAE Guidline 35 (G36), PART 5.N.8.(for multi zone VAV AHU), PART 5.P.6 and PART3.2B.3 (for single zone VAV AHU).

Single zone VAV AHU: Control of actuated exhaust dampers without fans (PART 5.P.6)

1. Exhaust damper position setpoints (PART3.2B.3)
   • minExhDamPos is the exhaust damper position that maintains a building pressure of 12 Pa (0.05 inchWC) while the system is at minOutPosMin (i.e., the economizer damper is positioned to provide minimum outdoor air while the supply fan is at minimum speed).
   • maxExhDamPos is the exhaust damper position that maintains a building pressure of 12 Pa (0.05 inchWC) while the economizer damper is fully open and the fan speed is at cooling maximum.
2. The exhaust damper is enabled when the associated supply fan is proven on and any outdoor air damper is open uOutDamPos > 0 and disabled and closed otherwise.
3. The exhaust damper position is reset linearly from minExhDamPos to maxExhDamPos as the commanded economizer damper position goes from minOutPosMin to outDamPhyPosMax.

The control sequence is as follows:

Revisions

• October 18, 2017, by Michael Wetter:
  Revised documentation.
• May 12, 2017, by Jianjun Hu:
  First implementation.