# Consumption Behaviour

> Symcon documentation · English · generated on 2026-09-26  
> Index: https://www.symcon.de/en/llms.txt

Source: https://www.symcon.de/en/service/documentation/module-reference/energy/consumption-behaviour/

_Requires Symcon >= 6.0_

The module calculates the probable consumption for the period based on an outdoor temperature variable and a meter variable using linear regression. The more values are available for the outdoor temperature and the meter, the more accurately the expected consumption can be determined.

### functional scope
- Calculates a probable consumption from two variables

### Software installation
- Via the [Module Store](https://www.symcon.de/en/service/documentation/components/management-console/module-store/) install the 'Consumption Behaviour' module.

### Set up instances in IP-Symcon
- Under 'Add Instance' the 'Consumption Behaviour' module can be found using the quick filter.
  - More information about adding instances in the [Instances documentation](https://www.symcon.de/en/service/documentation/basics/instances/)

#### Configuration Page:

| name                             | description                                                                 |
| -------------------------------- | --------------------------------------------------------------------------- |
| Variable for outdoor temperature | Logged variable for outdoor temperature                                     |
| Variable for counter             | Logged variable for counter                                                 |
| Period                           | Period for which the calculation is to be performed                         |
| Limit                            | Maximum number of records to be used for the regression. 0 = No limit       |
| Interval                         | Time interval of the timer in which the variable should be calculated again |
| Calculate                        | Button to recalculate the variable                                          |

For the counter variable, there must be at least 2 records for 3 consecutive periods for a calculation to take place. For period day, the hourly aggregation of the variables is used. For all other periods the daily aggregation of the variables is used.

### status variables
The status variables/categories are created automatically. Deleting individual ones can lead to malfunctions.

#### Status variables

| Name                                               | Type  | Description                                                                              |
| -------------------------------------------------- | ----- | ---------------------------------------------------------------------------------------- |
| Expectation of current period                      | float | Displays the expected consumption based on the outdoor temperature of the current period |
| Expectation of the last period                     | float | Displays the expected consumption based on the outdoor temperature of the last period    |
| Extrapolation of the current period                | float | Displays the extrapolated consumption of the current period                              |
| Extrapolation of the last period                   | float | Displays the extrapolated consumption of the last period                                 |
| Value of the current period                        | float | Displays the current consumption of the current period                                   |
| Value of the last period                           | float | Displays the consumption of the last period                                              |
| Percent of the current period                      | float | Shows how far the extrapolated consumption differs from the expected value in percent    |
| Percent of the last period                         | float | Shows how far the extrapolated consumption differs from the expected value in percent    |
| Coefficient of determination of the current period | float | Accuracy of the expectation calculation of the current period                            |
| Coefficient of determination of the last period    | float | Accuracy of the expectation calculation of the last period                               |

#### Mathematical formulas

Expectation is calculated using simple linear regression. [Mathematically Explained](https://en.wikipedia.org/wiki/Simple_linear_regression). Here the sum of the positive result is calculated from the calculation m * temperature average (depending on the period) * b. m and b are determined by the linear regression.

The extrapolation again consists of the average value of the period multiplied by the period length.

## VBV_UpdateCalculation

Source: https://www.symcon.de/en/service/documentation/module-reference/energy/consumption-behaviour/vbv-updatecalculation/

`bool VBV_UpdateCalculation(int $InstanceID)`

_Requires Symcon >= 5.0_

**Parameters**

- `$InstanceID` (int): ID of the Instance

**Returns** (bool): If the command could be executed successfully, it returns __TRUE__ as result, otherwise __FALSE__.

ID of the Instance

**Example**

```text
VBV_UpdateCalculation(12345);
```