Example: Setting Up Ventilation Rate Procedure as the Outdoor Air Method

Note: It is important to review Setting up Outdoor Air Design and Air Distribution Requirements as well. Once you have completed those steps, selected a Zone Conditions Template for each of the Zone HVAC Group and completed the steps below, you are ready to go...

EnergyPlus version 7.2 contains the ASHRAE Standard 62 calculations for the Ventilation Rate Procedure (VRP). To incorporate the VRP into a BEM the user should review the hierarchy and the images below.

Hierarchy of Setting VRP as the Outdoor Air Method

The Hierarchy should be read from the bottom up, and is meant to provide some context.

· System Type - The Air Loop is included in the comprehensive set of Zone HVAC Groups, Air and Water Loops.

§ Air Loop Type - The user selects the supply side template

o Air Loop Supply Side Template - the template that the library can be associated with for the "Sizing" Property

♦ [Start Here] Libraries Category: Libraries/Sizing Params Workspace

· Library Entry (Type & Sub Type) - user selects Type = HvacDesign and Sub Type = AirLoopSizing to create a new library entry, edit an existing one, or copy and edit an existing one.

§ Library Entry Field: System Outdoor Air Method - user selects Ventilation Rate Procedure

§ Library Entry Field: Zone Maximum Outdoor Air Fraction - user sets the fraction between 0 and 1.

Steps to Incorporate Ventilation Rate Procedure:

The following identifies the steps required to engage the hierarchy displayed above.

Note: Once the library entries and the templates have been set up the user can just be working at the Air Loop and System level to incorporate VRP (Step 3).

Step 1: Defining Library Entry

Step 2: Associating Library Entry with Air Loop Template

The image below displays the Template/System Templates/Air Loops workspace where the "Sizing" property is defined. Within the Value cell is a drop down list that will provide the options for the library entries that are associated with the Sizing Params/HvacDesign/AirLoopSizing.

Step 3: Associating Library Entry with Air Loop Template

The image below displays the Systems/Air Loop workspace, where the user can select the Air Loop Supply Template that the OFFICE_AirLoopSizing library entry associated with it (image above). The user can also change/override the selection as well (highlighted red field on the right)

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