HAC_EEI1: HVAC energy-efficiency indicator 1, rule 1

Block HAC_EEI1 (FB841) calculates whether a manual setpoint shift meets the given conditions for energy efficiency and supplies the result to the output.
(Rule1: Monitor manual setpoint shift). HAC_EEI1_SiUn (FB841), HAC_EEI1_UsUn (FB798)

Principle of operation

The calculates whether the manual setpoint shift [SpSh] results in higher energy consumption for heating ([HCSta] = 2) or cooling ([HCSta] = 3) and whether the setpoint shift exceeds the set tolerance thresholds [TolMaxEei1].

 

IF

THEN

Heating

[HCSta] = 2

[SpSh] > [TolMaxEei1]

[Out] = 1

Cooling

[HCSta] = 3

[SpSh] < [TolMaxEei1]

[Out] = 1

Prerequisite:

Calculation only takes place if the priority for the manual intervention [SpShPrPrio] =13.

Note: The block evaluates the last setpoint shirt based on the existing room condition. It is possible that the last setpoint shift may no longer be evaluated as energy efficient if the framework condition changes.

Example: The setpoint is reduced during boost heating in the room. The setpoint shift was evaluated as energy efficient.

But then demand for cooling occurred later, as the room was occupied. In this relationship, the last setpoint shift is evaluated as not energy efficient since the setpoint is now specified that is lower than necessary.

Inputs

PIN

E

Description

TolMaxEei1

pax

Max. tolerance for energy efficiency indicator 1

HCSta

 

Heating/cooling state

1 (none)

 

2 (heating)

Heating state.

3 (cooling)

Cooling state.

SpSh

 

Setpoint shift

SpShPrPrio

 

Setpoint shift present priority.

Outputs

PIN

E

Description

Out

 

Output

0 (No)

Energy efficiency met.

1 (Yes).

Energy efficiency not met.

Input values

PIN

Description

Data type

Default value

Engineering unit or text group

Min.

Max.

TolMaxEei1

Max. tolerance for energy efficiency indicator 1

REAL

1.0

K

-3.40E38

3.40E38

2.0

°F

-3.40E38

3.40E38

HCSta

Heating/cooling state

INT

1

Neither heating/cooling.

1

3

SpSh

Setpoint shift

REAL

0.0

K

-20.0

20.0

0.0

°F

-36.0

36.0

SpShPrPrio

Setpoint shift present priority.

INT

15

BA present priority for SystemOne

0

17

Output values

PIN

Description

Data type

Default value

Engineering unit or text group

Min.

Max.

Out

Output

BOOL

0

No, Yes

 

 

 

Process response

Standard (see General rules and information).

Troubleshooting

Standard (see General rules and information).