Fan coil unit ventilation control (FcuVntCtl11)

Overview

The application function "Fan coil unit ventilation control 11" (FcuVntCtl11) collaborates with FCU fans for ventilation and/or room air quality control.

Function

Different modes are available for ventilation control; the behavior is selectable by parameter.

Ventilation mode
The ventilation mode can be set per room operating mode to:

Off
Minimum (Minimum outside air damper position)
Dcv (Demand controlled ventilation) ¹⁾
Dcv & Min (Demand controlled ventilation with a minimum outside air damper position limit) ¹⁾

¹⁾ Air quality sensor required in the room.

The table shows factory default settings for min vent and air quality parameters:

Plant mode	Ventilation mode	Sp air quality [ppm]	Outside air damper min position [%]
1 Off	Off
2 Protection*	Off	1500	20
3 Economy*	Off	1500	30
4 Pre-Comfort*	Dcv	1100	40
5 Comfort*	Min & Dcv	900	50
6 Warm-up	Off
7 Cool down	Off
8 Room low temperature protection (frost)	Off
9 Condensate overflow	Off
10 Free cooling	Depends on ROpMod	Depends on ROpMod	Depends on ROpMod
11 Night cooling	Off
12 Ventilation	s/a Comfort	s/a Comfort	s/a Comfort
13 Equipment temperature protection	Off
14 Emergency off	Off
Not used
Not used
Not used

*For these modes the parameters can be individually adjusted.

Periodic fan kick
Parameters are available to configure periodic cycling of the fan on and off. The fan can be enabled to run at the lowest speed at regular intervals, for the length of time in TiOnDutyCyc. See figure.

The length of the duty cycle off interval can be configured for each operating mode (DutyCycCmf, DutyCycPcf, DutyCycEco, DutyCycPrt). A duty cycle of 0min (default) means the feature is disabled.

Note
If the room temperature is measured with an extract air temperature sensor, the fan must be switched on to ensure the effective room temperature is measured correctly. In this case, periodic fan kick can be used to periodically cycle the fan.

Exception handling
For air quality control, the ventilation mode must be set to Dcv or Min & Dcv, FanAvlVent must be Yes and the air quality sensor must be Valid. If the sensor is failed or absent, then the ventilation mode cannot be Dcv or Min & Dcv; in this case FanVntReq is set to Min.

Configuration

Objects

Description	Object	Type	Default value
Setpoint room air quality for comfort	SpAQualRCmf	ACnfVal	900 [ppm]
Setpoint room air quality for pre-comfort	SpAQualRPcf	ACnfVal	1100 [ppm]
Setpoint room air quality for economy	SpAQualREco	ACnfVal	1500 [ppm]
Setpoint room air quality for protection	SpAQualRPrt	ACnfVal	1500 [ppm]

Parameters

Description	Parameter	Default value
Comfort configuration 1:Off 2:Minimum ventilation 3:Demand-controled ventilation 4:Minimum ventilation & Demand-controlled ventilation	CmfCnf	4:Minimum ventilation & Demand-controlled ventilation
Pre-Comfort configuration Enumeration see CmfCnf	PcfCnf	3:Demand-controled ventilation
Economy configuration Enumeration see CmfCnf	EcoCnf	2:Minimum ventilation
Protection configuration Enumeration see CmfCnf	PrtCnf	2:Minimum ventilation
Minimum position outside air damper for comfort	DmpOaPosMinCmf	50 [%]
Minimum position outside air damper for pre-comfort	DmpOaPosMinPcf	40 [%]
Minimum position outside air damper for economy	DmpOaPosMinEco	30 [%]
Minimum position outside air damper for protection	DmpOaPosMinPrt	20 [%]
Duty cycling in comfort	DutyCycCmf	0 [min]
Duty cycling in pre-comfort	DutyCycPcf	0 [min]
Duty cycling in economy	DutyCycEco	0 [min]
Duty cycling in protection	DutyCycPrt	0 [min]
Switch-on time duty cycling ▶ If periodic cycling of ventilation air flow is desired, TiOnDutyCyc defines the length of "on" time for the ventilation air flow. Periodic cycling requires duty cycle parameter(s) to be set to non zero value (DutyCycCmf, DutyCycPcf, DutyCycEco, DutyCycPrt).	TiOnDutyCyc	6 [min]

Interface

Interface	Description	Type	Ref.	Owned by
PrSpVnt	Present ventilation setpoint	APrcVal	●	-
DmpOaVntCtr	Ventilation controller for outside air damper	Controller	●	-
FanVntCtr	Ventilation controller for fan	Controller	●	-
RCtl	Room control	GrpMaster	◉	Room
SpAQualRCmf	Setpoint room air quality for comfort	ACnfVal	●	-
SpAQualRPcf	Setpoint room air quality for pre-comfort	ACnfVal	●	-
SpAQualREco	Setpoint room air quality for economy	ACnfVal	●	-
SpAQualRPrt	Setpoint room air quality for protection	ACnfVal	●	-