Ceiling heating with hot water (HcgHw11)

This application function operates hot water valve(s) for radiant ceiling device(s) such as ceiling panel(s).

The valve position is calculated based a request signal (from the room controller) received for heating.

Multiple panel control is supported.

Required elements and how to configure them:

Element	I/O	Signal type
RcgVlvPosH "Radiant ceiling valve position for heating"	On-board output, Radiant ceiling valve position 1	Heating

Function

The figure below shows BACnet objects associated with this application function. Primary signal flow is summarized as follows:

Radiant ceiling heating request (RcgHReq) is received and processed into the output signal for radiant ceiling valve position (RcgVlvPosH).

Basic function: Accept request signal from associated room controller and pass it through a device mode logic switch; Output the result as a command to the BACnet object that controls the device.

	Command or request (or related)
	Notification of condition or status, or availability
	Device mode

Hot water valve modulation: In response to heating demand, the heating valve is modulated to control the room temperature at setpoint. In response to external triggers for special modes such as warm-up, cool down, or safety conditions, the heating valve may be set to off or fully open.

Note
This AF does not perform loop control; its main purpose is to run commands. Loop control processes (for this AF) are managed in the "room" AF(s) that collaborate with this AF to command the end device.

Multiple panel control: The radiant ceiling valve position heating collection object (RcgVlvPosHCol) can reference and control multiple ceiling valve actuators.

Radiant ceiling valve position heating objects (RcgVlvPosH) are referenced by the radiant ceiling valve position heating collection object (RcgVlvPosHCol); this collection object is a common node for any / all RcgVlvPosH object(s). The value for RcgVlvPosH comes from RcgVlvPosHVal.

Device mode: The input signal for device mode is a multistate value.

RcgDevMod supports the following states:

Off
Control mode (modulation)
Fully open

Heating available status: When the ceiling panel(s) are available for heating, the binary output signal for "Radiant ceiling available for heating" (RcgAvlH) will be "Yes" (available). RcgAvlH is used by the system to regulate heating resources. For example, if there is a call for heating but the ceiling panel(s) are not available because they are already at maximum capacity (because device mode is fully open), then RcgAvlH will signal "No" and the next available heating resource in the temperature control sequence will be activated.

For heating available status to be "Yes", device mode must equal "Control mode" (modulation).

Supply chain interface, HwDmd: The output signal for hot water demand is a multistate value.

RcgHwDmd supports the following states:

Off (no demand signal)
Heating demand (demand signal is active)
Warm-up (Hot water demand is initiated when plant operating mode is set to warm-up)

The following figure(s) illustrates control modulation and related functions.

HysHwDmd	Hysteresis for hot water demand
RcgHwDmd	Radiant ceiling hot water demand
RcgVlvPosH	Radiant ceiling valve position for heating
SpH	Setpoint for heating
SwiOnPtHwDmd	Switch-on point for hot water demand

Configuration

Parameters

Description	Parameter	Default value
Hot water demand
Switch-on point for hot water demand ▶ When the ceiling heating valve position is greater than the switch-on point, the ceiling heating valve enables request hot water for heating.	SwiOnPtHwDmd	4 [%]
Hysteresis for hot water demand ▶ When the ceiling heating valve position is less than the hysteresis value, the radiant ceiling heating valve disables request hot water for heating.	HysHwDmd	2 [%]

Interface

Interface		Description	Type	Ref.	Owned by
RcgVlvPosHCol		Collection of radiant ceiling valve position for heating	ColView	●	-
	RcgVlvPosH	Radiant ceiling valve position for heating (1...n)	AO	◉	Room segment / Device
RcgVlvPosHVal		Radiant ceiling valve position value for heating	APrcVal	●	-
RcgDevMod		Radiant ceiling device mode 1:Off 2:Control mode 3:Fully open	MPrcVal	●	-
RcgHReq		Radiant ceiling heating request	ACalcVal	●	-
RcgAvlH		Radiant ceiling available for heating 0:No 1:Yes	BCalcVal	●	-
RcgHwDmd		Radiant ceiling hot water demand 1:Off 2:Heating demand 3:Warm-up	MCalcVal	●	-
RcgSplyHw		Radiant ceiling supply chain for hot water	GrpMbr	●	Room segment

Engineering and commissioning

Verify operation for single output and multiple output.

Consider controlling the space as separate segments, rather than multiple objects in one segment. This allows the panels to operate individually.