[Hdd21] Heating degree days
Program block, name / node subtype: [Hdd21] Heating degree days
Library hierarchy: Heating functions
Family: Hdd
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Configurator
Program blocks are stored in the library without I/Os. Use the auto-create and auto-connect functions to create I/Os and/or to connect them to the interface blocks, e.g., R_A, CMD_B. Alternatively, take the I/Os from the folder containing the predefined I/Os in the library and/or from the plant and connect them to the interface blocks.
Calculates heating days and heating degree days from the outside air and room temperature.
Calculating heating days
The day is considered a heating day when the day average of the outside air temperature (TOa) is below the heating limit.
In this case, the number of heating days (HDay) is increased by 1.
Calculating heating degree days
When a heating day is established, the difference between the day average of the outside air temperature and the day average of the room temperature is calculated and the result is added to the heating degree days (Hdd).
Reset
The heating days and heating degree days can be reset to zero on the input pin [Reset]. The values prior to the last reset are stored in [HDayOld] and [HddOld].
"Reset month" compares the set month and the current date. If the date matches, the program automatically resets all values in [HDay] and [Hdd] but saves the old values in [HDayOld] and [HddOld].
This program block has the following optional functions:
Option: Reset month
Compares the set month and the current date. If the date matches, the program automatically resets all values for heating days and heating degree days but saves the old values.
Name | Description | Type | Alarm / Notification class | Trend / Type | |
|---|---|---|---|---|---|
HDay | Heating days | ASmpPrcVal: Analog simple process value | No | No | |
Hdd | Heating degree days | ASmpPrcVal: Analog simple process value | No | No | |
HDayOld | Old heating days | ASmpPrcVal: Analog simple process value | No | No | |
HddOld | Old heating degree days | ASmpPrcVal: Analog simple process value | No | No | |
Description |
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Reset month |