.Buildings.Controls.OBC.ASHRAE.G36.AHUs.MultiZone.VAV.SetPoints.PlantRequests

Output plant requests for multizone air handling unit

Information

This sequence outputs the system reset requests for multiple zone air handling unit. The implementation is according to the Section 5.16.16 of ASHRAE Guideline 36, May 2020.

Chilled water reset request yChiWatResReq

  1. If the supply air temperature TAirSup exceeds the supply air temperature set point TAirSupSet by 3 °C (5 °F) for 2 minutes, send 3 requests.
  2. If the supply air temperature TAirSup exceeds the supply air temperature set point TAirSupSet by 2 °C (3 °F) for 2 minutes, send 2 requests.
  3. Else if the chilled water valve position uCooCoiSet is greater than 95%, send 1 request until the uCooCoiSet is less than 85%.
  4. Else if the chilled water valve position uCooCoiSet is less than 95%, send 0 request.

Chiller plant request yChiPlaReq

Send the chiller plant that serves the system a chiller plant request as follows:

  1. If the chilled water valve position uCooCoiSet is greater than 95%, send 1 request until the uCooCoiSet is less than 10%.
  2. Else if the chilled water valve position uCooCoiSet is less than 95%, send 0 request.

If there is a hot-water coil, hot-water reset requests yHotWatResReq

  1. If the supply air temperature TAirSup is 17 °C (30 °F) less than the supply air temperature set point TAirSupSet for 5 minutes, send 3 requests.
  2. Else if the supply air temperature TAirSup is 8 °C (15 °F) less than the supply air temperature set point TAirSupSet for 5 minutes, send 2 requests.
  3. Else if the hot water valve position uHeaCoiSet is greater than 95%, send 1 request until the uHeaCoiSet is less than 85%.
  4. Else if the hot water valve position uHeaCoiSet is less than 95%, send 0 request.

If there is a hot-water coil and heating hot-water plant, heating hot-water plant reqeusts yHotWatPlaReq

Send the heating hot-water plant that serves the air handling unit a heating hot-water plant request as follows:

  1. If the hot water valve position uHeaCoiSet is greater than 95%, send 1 request until the hot water valve position is less than 10%.
  2. If the hot water valve position uHeaCoiSet is less than 95%, send 0 requests.

Revisions

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