VAV temperature cascade control heating (VavTCasCtlH11)

Overview

The application function "VAV temperature cascade control for heating 11" (VavTCasCtlH11) is the hub for the sequencing of the room temperature controllers for VAV heating. It determines the room heating setpoint and the room heating demand signals to maintain the room temperature at the heating setpoint.

For the heating coils, the room demand output signal is designed for cascaded supply temperature control in the room segment. (air sensor(s) required)

The following devices in the room segment are supported:

Heating/Cooling coil
Heating/Chilled ceiling
Heating coil
Radiator
Floor heating
Supply air damper

Function

This AF works in collaboration with a room segment temperature control AF. The heating room temperature PID controller is enabled based on a signal that is read via the grouping function (from equipment in the room segment) indicating whether heating is available.

Devices for heating are activated in the following order (default):
Floor heating > Radiator > Heated ceiling > Heating coil > VAV

Heating setpoint and plant mode

	Plant operation mode	Heating setpoint
1	Off	Protection heating
2	Protection	Protection heating
3	Economy	Economy heating
4	Pre-Comfort	Pre-Comfort heating
5	Comfort	Comfort heating
6	Warm-up	Comfort / Pre-Comfort heating¹
7	Cool down	Protection heating
8	Room low temperature protection	Protection heating
9	Not used
10	Free cooling	Protection heating
11	Night cooling	Protection heating
12	Ventilation	Comfort heating
13	Not used
14	Air volume flow off	Protection heating
15	Smoke extraction positive pressure	Protection heating
16	Smoke extraction negative pressure	Protection heating
17	Purge	Protection heating

¹⁾ Depends on Next room operating mode (NxROpMod) in HvacPltMod AF.

Feature configuration

Feature selections for "Room HVAC coordination" are accessed via the Application configuration task in the Configuration component.

Feature (AF)	Feature description	Ref.
Trend for present heating setpoint	None/Active	☑

Configuration

Objects

Description	Object	Type	Default value
Heating setpoint for comfort ▶ Default command must be configured on priority level 17. 0...50 [°C], 32.0...122.0 [°F]	SpHCmf	APrcVal	21 [°C] 70.0 [°F]
Delta heating setpoint for pre-comfort ▶ Delta between comfort and pre-comfort setpoints. 0...10 [K], 0.0...18.0 [°F]	DSpHPcf	ACnfVal	1 [K] 2.0 [°F]
Heating setpoint for economy 0...50 [°C], 32.0...122.0 [°F]	SpHEco	ACnfVal	15 [°C] 55.0 [°F]
Heating setpoint for protection 0...50 [°C], 32.0...122.0 [°F]	SpHPrt	ACnfVal	12 [°C] 53.6 [°F]

Parameters

Description	Parameter	Default value
Offset for VAV start ▶ Vav flow temperature control gets a lower setpoint.	OfsVavStt	0 [K] 0.0 [°F]
Comfort configuration 1:None ▶ None, means no aggregate is activated depending on heating demand. 2:Radiant devices ▶ Radiant device, means only radiant devices (e.g. Radiator) will be activated depending on heating demand. 3:Air treatment devices ▶ Air treatment devices, means only air treatment devices (Heating coil, Fan) will be activated depending on heating demand. 4:Radiant & air treatment devices ▶ Radiant & air treatment devices, both will be activated depending on heating demand.	CmfCnf	4:Radiant & air treatment devices
Pre-Comfort configuration Enumeration see CmfCnf	PcfCnf	4:Radiant & air treatment devices
Economy configuration Enumeration see CmfCnf	EcoCnf	4:Radiant & air treatment devices
Protection configuration Enumeration see CmfCnf	PrtCnf	4:Radiant & air treatment devices
Warm-up configuration Enumeration see CmfCnf	WarmUpCnf	4:Radiant & air treatment devices
Coil: Controller mode by comfort 0:Continuous 1:2-position ▶ 2-position, the output will be 0 or 100 % nothing between, be aware of delays.	CoilCmf	0:Continuous
Coil: Controller mode by pre-comfort Enumeration see CoilCmf	CoilPcf	0:Continuous
Coil: Controller mode by economy Enumeration see CoilCmf	CoilEco	0:Continuous
Coil: Controller mode by protection Enumeration see CoilCmf	CoilPrt	0:Continuous
Coil: Controller mode by warm-up Enumeration see CoilCmf	CoilWarmUp	0:Continuous
Radiant devices: Controller mode by comfort Enumeration see CoilCmf	RadDevCmf	0:Continuous
Radiant devices: Controller mode by pre-comfort Enumeration see CoilCmf	RadDevPcf	0:Continuous
Radiant devices: Controller mode by economy Enumeration see CoilCmf	RadDevEco	0:Continuous
Radiant devices: Controller mode by protection Enumeration see CoilCmf	RadDevPrt	0:Continuous
Radiant devices: Controller mode by warm-up Enumeration see CoilCmf	RadDevWarmUp	0:Continuous
Radiant floor heating sequence	RfrHSeq	1 [1..8 unique]
Radiator heating sequence	RadHSeq	2 [1..8 unique]
Radiant ceiling heating sequence	RcgHSeq	3 [1..8 unique]
Coil heating sequence	CoilHSeq	4 [1..8 unique]
VAV heating sequence	VavHSeq	5 [1..8 unique]
Temperature difference unit ▶ Defined by selected engineering unit – do not change.	TDiffUnit	[K] [°F]

Interface

Interface	Description	Type	Ref.	Owned by
PrSpH	Present heating setpoint	APrcVal	●	-
TrndPrSpH	Trend for present heating setpoint	FtrSel	☑	-
PrSpHCmf	Present heating setpoint for comfort	ACalcVal	●	-
PrSpHPcf	Present heating setpoint for pre-comfort	ACalcVal	●	-
PrSpHEco	Present heating setpoint for economy	ACalcVal	●	-
PrSpHPrt	Present heating setpoint for protection	ACalcVal	●	-
VavTRCtrH	Room temperature controller heating for VAV	Controller	●	-
CoilTRCtrH	Room temperature controller heating for coil	Controller	●	-
RcgTRCtrH	Room temperature controller heating for radiant ceiling	Controller	●	-
RadTRCtrH	Room temperature controller heating for radiator	Controller	●	-
RfrTRCtrH	Room temperature controller heating for radiant floor	Controller	●	-
RCtl	Room control	GrpMaster	◉	Room
SpHCmf	Heating setpoint for comfort	APrcVal	●	-
DSpHPcf	Delta heating setpoint for pre-comfort	ACnfVal	●	-
SpHEco	Heating setpoint for economy	ACnfVal	●	-
SpHPrt	Heating setpoint for protection	ACnfVal	●	-

Engineering and commissioning

Radiant floor is likely to change room temperature slower than other HVAC equipment. For specific projects, it may be useful to slow down the action of the relevant room temperature controller (continuous, PID) or change the controller mode to 2-position.