Uncontrolled Air Terminal

Stencil: Zone HVAC Stencil: G-Single Duct Uncontrolled

Type: Air Terminal

Sub Type: Uncontrolled

Note: Requires a connection to a hot water loop

EnergyPlus IDF Objects

EnergyPlus Object - AirTerminal:SingleDuct:Uncontrolled

Central system air is usually supplied to a zone through a terminal unit such as a single duct VAV reheat box. Sometimes, however, it is desirable to supply central system air directly to a zone without any zone level control or tempering. An example would be a single zone reheat system.

The control zone receives supply air directly from the central system since the supply air temperature has been adjusted to control the temperature in the control zone. The slave zones then have baseboards or reheat coils to allow some temperature adjustment. The AirTerminal:SingleDuct:Uncontrolled object creates the capability of supplying central system air directly to a zone. Its input consists of the object name, an availability (on/off) schedule, and a node name. This node is both a zone inlet node and an outlet node of the AirLoopHVAC:ZoneSplitter.

For the objects to work correctly, it is important in any systems including Direct Air objects for the sum of the maximum zone air flow rates to be equal to the maximum central system flow rate. The zone maximum flow rates are specified in the zone terminal unit or direct air inputs. The central air system flow rate is specified in the AirLoopHVAC input and also in the air loop branch and central fan inputs.

Component Properties

The table shows the properties that are displayed when the component is selected while in diagram mode. The second column shows the selection options available that are dictated by EnergyPlus or it shows the source for the library entries that are displayed in the drop down list.

Property Name	Value Sources/Options
Name	Simergy provides unique name (editable)
Availability Schedule Name
Maximum Air Flow Rate	0-Min, Autosize

Name

Simergy automatically defines a unique name for each component. This can be changed by the user if desired.

Field: Availability Schedule Name

Schedule that this component will operate or is available to operate.

Field: Maximum Air Flow Rate

The design constant volume flow rate (m³/sec) specified for the terminal reheat ADU.

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