HeatCoolUsingOutdoorAir (FB)¶

FUNCTION_BLOCK HeatCoolUsingOutdoorAir

Using passiv cooling (and eventually heating) using outdoor air (and an outdoor air actuator) in “economy” energy level to get the indoor air temperature in the “comfort” energy level setpoint range. For an explanation of the different energy levels see EnergyLevelSetpoint.

The purpose of this functionality is to optimize energy consumption.

Functionality¶

HeatCoolUsingOutdoorAir provides a optimization strategy for room temperature control using an outdoor air actuator for passive cooling (and eventually but unlikely heating). WindowActuator or an outdoor air damper / fan assembly can be used as an outdoor air actuator. Operating the outdoor air actuator is enabled only if the room is set to “economy” energy level and the outdoor air temperature is inbetween the “protection” energy level setpoints.

Cooling mode¶

In case indoor air temperature is above (comfort level) cool setpoint plus hysteresis and outdoor air temperature is below cool setpoint minus treshold the outdoor air actuator is opened. In case the indoor air temperature is falling below (comfort level) cool setpoint the outdoor air actuator is closed.

Heating mode¶

Heating mode operates vise versa, is unlikely given typical building usage and climate patterns, but it’s no hazzle to use it by chance.

HeatCoolUsingOutdoorAir is oriented towards VDI 3814 3.1 “Optimisation functions” “Night-time cooling” (6.3.6.5).

InOut:

Scope	Name	Type	Initial	Comment
Input	`xEnable`	`BOOL`	TRUE	Enable
	`eLevel`	EnergyLevel		Energy level
	`rSetptHeatComfort`	`REAL`	21.0	Heat setpoint comfort level
	`rSetptCoolComfort`	`REAL`	23.0	Cool setpoint comfort level
	`rSetptHeatProtection`	`REAL`	10.0	Heat setpoint protection level
	`rSetptCoolProtection`	`REAL`	40.0	Cool setpoint protection level
	`rOdaTemp`	`REAL`	10.0	Outdoor air temperature
	`rIdaTemp`	`REAL`	22.0	Indoor air temperature
	`rTreshold`	`REAL`	2.0	Treshold to switch on passiv cooling / heating (in K)
	`rHysteresis`	`REAL`	0.5	Hysteresis to switch off passiv cooling / heating (in K)
Output	`xOpenOdaActuator`	`BOOL`		Open outdoor air actuator