Efficiency Calculation

Depending on the parameter EFF-02 (efficiency compensation) the formulas to calculate the air flow are shown in the next table:

efficiency

efficiency compensation

EFF-02

efficiency calculation formulas

extract air efficiency

0

1

supply air efficiency

0

1


In the formulas above:


The efficiency calculated with T2 will be probably not be 100% exact but good enough.

It is better us using an average temp sensor in the supply air after the ERC but it is a more expensive solution and could also end up showing a wrong value, because of different layers in the air (unmixed air) in addition to a possible challenging mounting.


The efficiency calculation start with a start-up delay defined by parameter EFF-01, after all the inputs "SupFan_running", "ExtFan_running" and "ERC_running"  are on,

The efficiency calculation will be displayed only, if the calculated value is bigger than EFF-03 with a fixed switching differential of 4K, otherwise it will display "0%" invalid.


Depending on the sensor configuration, the supply or the extract air efficiency is connected to the output "ERCEfficiency".

Whenever one of the sensor needed to calculate an efficiency output is missing, or when T1 = T3, the efficiency output will display the value "0%" meaning that there is no defined value for that efficiency.


Efficiency calculation compensation

The compensation of the energy efficiency can be done in two different ways:


When running the ERC with a control signal below 100% you must compensate the efficiency to get a correct calculation.

If the parameter EFF-02 = 1 the compensation multiplier (see table above) is added to the efficiency calculation.

If the multiplier is not accurate enough, set EFF-02 = 0 and edit the input characteristics of the input of the control signal.

To get the relation to the control signal to be right you could need make a separate characteristics related to that ERC control signal "ERCCtrlSig".

E.g. you would then need to adjust the characteristics of the datapoint connected to  "ERCCtrlSig" input using the input characteristics  to match exactly the ERC efficiency in the different areas. This can be done in CARE.


Description

Range

Default

Units

EFF-01: Efficiency calculation start-up delay

1...3600

180

Sec

EFF-02: Efficiency calculation compensation

0/ 1

1

-

EFF-03: Minimum control signal for efficiency calculation; set efficiency to 0%

if the control signal < EFF-03

5...100

5

%