Package with control sequences from ASHRAE Guideline 36


This package contains control sequences from ASHRAE Guideline 36 (G36). All sequences are created using blocks from the Buildings.Controls.OBC.CDL library, following the CDL specification.

The G36 library is structured as follows:

Implementation of PID controllers

For the PID controllers, the implementation in Buildings.Controls.OBC.CDL.Continuous.LimPID is used. Hence, the PID controllers are in the standard form

y = k   ( e(t) + 1 ⁄ Ti   ∫ e(s) ds + Td de(t)⁄dt ),

where y is the control signal, e(t) = us - um is the control error, with us being the set point and um being the measured quantity, k is the gain, Ti is the time constant of the integral term and Td is the time constant of the derivative term.

Note that the units of k are the inverse of the units of the control error, while the units of Ti and Td are seconds. As the units of flow rates and pressure can vary between orders of magnitude, for example depening on whether cfm, m3⁄s or m3⁄h are used for flow measurements, the control error is normalized as follows:

Guideline 36 is specific as the where a P or a PI controller should be used. These recommendations are used as the default control configuration. However, all controllers can be configured as P, PI or PID controller. This allows to configure a PI controller as a P controller as part of the tuning process.


BSR. ASHRAE Guideline 36P, High Performance Sequences of Operation for HVAC systems. First Public Review Draft (June 2016)

Extends from Modelica.Icons.VariantsPackage (Icon for package containing variants).

Package Content

Name Description
Buildings.Controls.OBC.ASHRAE.G36_PR1.AHUs AHUs AHU Sequences as defined in guideline G36
Buildings.Controls.OBC.ASHRAE.G36_PR1.Generic Generic Generic control sequences
Buildings.Controls.OBC.ASHRAE.G36_PR1.TerminalUnits TerminalUnits Control sequences for terminal units
Buildings.Controls.OBC.ASHRAE.G36_PR1.Types Types Package with type definitions for control sequences