About Zone Properties

Zones properties, such as heating and cooling temperatures and outdoor air information, determine the heating and cooling loads for the spaces in the building model.

With a zone selected in a view or in the System Browser, you can access zone properties as follows:

The following table lists the zone properties:

Parameter Description
Constraints
Level The base level on which the zone resides. This is a calculated value.
Mechanical - Airflow
Calculated Supply Airflow The total supply airflow for the zone calculated by Systems Analysis, or read from an imported gbXML file.
Calculated Supply Airflow per area The Calculated Supply Airflow of the zone divided by the total area of the zone. This value is calculated by Systems Analysis, or read from an imported gbXML file.
Dimensions
Occupied Area The sum of the areas for all of the occupied spaces in the zone. This is a calculated value.
Gross Area The sum of the areas for all of the occupied and unoccupied spaces in the zone. This is a calculated value.
Occupied Volume The sum of the volumes for all occupied spaces in the zone. This is a calculated value.
Gross Volume The sum of the volumes for all occupied and unoccupied spaces in the zone. This is a calculated value.
Perimeter The sum of the perimeters for all the spaces in the zone. All common parameters shared by these spaces are omitted from the calculation. This is a calculated value.
Note: To improve performance, this parameter is disabled for Default zones.
Identity Data
Comments Text comments for the zone.
Name Name of the zone. Each name must be unique.
Phasing
Phase The project phase to which the zone belongs. This is a read only value based on the view properties. See Working with Phases and Zones for more information about phases and zones.
Energy Analysis
Service Type The heating and cooling service for the zone. You can select a specific service type or accept the default specified as the <Building> service type for the zone.
Coil Bypass The manufacturer’s coil bypass factor. This is a measure of efficiency that indicates the volume of air passing through the coil that is unaffected by the coil temperature.
Cooling Information Opens the Cooling Information dialog where you specify the cooling information for the zone.
Heating Information Opens the Heating Information dialog where you specify the heating information for the zone.
Outdoor Air Information Opens the Outdoor Air Information dialog where you specify the outdoor air information for the spaces in the zone.
Outdoor Air Method The method for calculating outdoor air for the zone. The calculation method ASHRAE 62.1 implements the Ventilation Rate Procedure from ASHRAE Standard 62.1. For a valid calculation result using this method, the Primary Airflow must be defined for each space in the zone.
Outdoor Air Method Settings Opens the Outdoor Air Calculation Setting dialog where you specify the outdoor air calculation information for the spaces in the zone.
Outdoor Air The total outdoor air for a zone. This is a calculated value.
Calculated Heating Load The total heating load for the zone calculated by Systems Analysis, or read from an imported gbXML file. Not Computed is displayed prior to Systems Analysis or gbXML import.
Calculated Heating Load per area The Calculated Heating Load of the zone divided by the total area of the zone. This value is calculated by Systems Analysis, or read from an imported gbXML file. Not Computed is displayed prior to Systems Analysis or gbXML import.
Calculated Area per Heating Load The total area of the zone divided by the Calculated Heating Load of the zone. This value is calculated by Systems Analysis, or read from an imported gbXML file. Not Computed is displayed prior to Systems Analysis or gbXML import.
Calculated Cooling Load The total cooling load for the zone calculated by Systems Analysis, or from an imported gbXML file. Not Computed is displayed prior to systems analysis or gbXML import
Calculated Cooling Load per area The Calculated Cooling Load of the zone divided by the total area of the zone. This value is calculated by Systems Analysis, or read from an imported gbXML file. Not Computed is displayed prior to Systems Analysis or gbXML import.
Calculated Area per Cooling Load The total area of the zone divided by the Calculated Cooling Load of the zone. This value is calculated by Systems Analysis, or read from an imported gbXML file. Not Computed is displayed prior to Systems Analysis or gbXML import.