HeatingCharacteristicCurve (FB)¶

FUNCTION_BLOCK HeatingCharacteristicCurve

HeatingCharacteristicCurve computes the approppriate water heating system supply temperature from outdoor air temperature.

Application example¶

Hot water heating systems are widely used in building automation and work with radiators, convectors or floor / wall heating pipes.

Functionality¶

HeatingCharacteristicCurve does compute the supply temperature using a simple linear equation, which is sufficient for most applications.

rOutdoorTemp < 15°C: rSupplyTemp := rRoomReferenceTemp + rShift - rGradient * (rOutdoorTemp - 24.0) rOutdoorTemp >= 15°C: rSupplyTemp := rRoomReferenceTemp + rShift - rGradient * (1.8 * rOutdoorTemp - 36.0)

rSupplyTemp is limited by rMinimumSupplyTemp and rMaximumSupplyTemp.

Typical setup for radiators and convectors: rGradient 1.0 .. 1.5 Typical setup for floor / wall heating: rGradient 0.4 .. 0.7

Default settings are chosen for radiators and convectors.

InOut:

Scope	Name	Type	Initial	Comment
Input	`rOutdoorTemp`	`REAL`	0.0	Outdoor temperature
	`rRoomReferenceTemp`	`REAL`	20.0	Room temperature reference value
	`rGradient`	`REAL`	1.2	Gradient
	`rShift`	`REAL`	0.0	Parallel shift
	`rMinimumSupplyTemp`	`REAL`	30.0	Minimum supply temperature
	`rMaximumSupplyTemp`	`REAL`	75.0	Maximum supply temperature
Output	`rSupplyTemp`	`REAL`		Supply temperature