Internorm Ventilation

Dieser Baustein dient der Steuerung einer Internorm I-tec Lüftung. Dabei können Luftfeuchtigkeit, CO2-Wert, sowie Raum- und Außentemperatur miteinbezogen werden.

When using a Motion/Presence Sensor, different ventilation speeds can be defined depending on presence.

For temperature support, the fan must be assigned as a source to a room controller. In addition, the system variable outdoor temperature is required.

Table of Contents


Abbreviation Summary Description Unit Value Range
Hi Analogue Input - Humidity inside [%]: If humidity exceeds parameter Hmax, the ventilation will increase. If this input is not connected, the humidity is not taken into account in the control. % 0...100
CO2 Analogue Input - indoor air pollution [ppm]: If CO2 exceeds the parameter CO2max, the ventilation will increase. If not connected, air pollution is not taken into account in regulation. ppm 0...∞
Ts Analogue Input - Outside Air Temperature: If not connected, temperature is not taken into account in control
If this input is not connected, the value of the system variable "outside temperature" is used. If this is also not available, the temperature support is deactivated.
Iw Digital Input Window Contact (ON = Window Open, OFF = Window Closed), if a window is open, ventilation is disabled. - -
Mv Digital Input - For signal from a Motion Sensor. The overrun time must be configured in parameters, the block will not make any further adjustments or configuration. - -
St STOP: Stops the fan while input is active. - -
Sl Digital Input - Sleep Mode: Turns off ventilation for the time set in parameter TSl. Afterwards, the block will start again with ventilation. - -
Tb BOOST: Terminates the control and sets the output to 100 percent. - -
Ex Digital input exhaust air: Stops the control and activates exhaust air at 100 percent.
ATTENTION: This input can only be used if the block property "Exhaust air/supply air operation allowed" is activated. This input is only visible in certain configurations.
- -
RtD Reset to block preset Resets parameters and settings of the block to the default values as specified in the block preset . Only possible when using a block preset! - -


Abbreviation Description Unit Value Range
AQs Analogue Output - Value indicates which parameter is driving the ventilation. This output is for informational reasons only.
0: Basic Ventilation, 1: Increased Humidity, 2: Temperature Control, 3: Poor Air Quality (CO2), 4: Manual Stop, 5: Window Open, 6: Manual Boost, 7: Manual Control User Interface, 8: Manual Exhaust Air, 9: Sleep Mode, 10: Frost Protection.
- 0...10
Qft Digital Output - Filter Change: Indicates whether air filters need to be changed. - -
Qe Analogue error output: Indicates if there is an error: 0 = No Error, 1 = Offline, 2 = Flaps closed, 100-115 = Internorm error code. -


Abbreviation Summary Description Unit Value Range Default Value
Hmax Maximum Humidity [%] Limit value maximum humidity: The block will attempt to keep the indoor air humidity below this value by means of suitable ventilation control. % 0...100 60
CO2max Maximum Air Pollution [ppm] Maximum tolerable air pollution: The block will attempt to keep the indoor air pollution below this value. ppm 0...∞ 1000
TH Motion Sensor Overrun Time [s] Overrun timer, which starts with the falling edge of the motion detector. Extends presence by the specified time. s 0...∞ 900
TSl Sleep Mode Hold Time [s] Overrun timer, which starts with the falling edge of the sleep input. Keeps the device off for a specified period of time. s 0...∞ 7200
Vi Intensive Ventilation During Absence [%] Intensive ventilation during absence: At humidity above Hmax or CO2 above CO2max the fan runs at this level. In temperature mode this value is used as maximum. % 0...100 100
V Basic Ventilation During Absence [%] Basic Ventilation (%) During "All Out": Fan operates at this level in automatic mode when absent. In Temperature mode, this value is used as the minimum. % 0...100 10
VPi Intesive Ventilation during Presence Intensive ventilation during presence: At humidity above Hmax or CO2 above CO2max the fan runs at this level. In temperature mode this value is used as maximum. % 0...100 60
VP Basic Ventilation during Presence Basic ventilation during presence. In automatic mode, fan operates at this level during motion/presence. In Temperature mode, this value is used as the minimum. % 0...100 20


Summary Description Default Value
Energy Costs Costs for running this source. Sources that have been configured to be 'Expensive' will only be requested by room controllers if no sources with higher priorities are available. -
Extract / Supply permitted Sets whether a fan is permitted to operate as extract only. When active, an extra input is available on the Leaf function block which can be used to start the extract mode. WARNING: If a room has an open fireplace an extract fan in close proximity may result in smoke being pulled into the room! -
Airflow direction (heat exchanger disabled) Sets the direction of ventilation when the heat exchanger is switched off for an Internorm fan. If the heat exchanger is active, there is no prevailing ventilation direction, supply air and exhaust air run simultaneously. -
Linked Fan Fan linked to this function block. Devices that can be assigned:
Internorm I-Tec Ventilation

Device Errors

If one or more ventilation apertures have been reported as closed, they must be reopened before operation can continue. If you device is reporting as offline, please check the power connection and wireless signal. Further information can be found here.

Maintenance Interval / Filter Change

The fan filters must be replaced or cleaned at regular maintenance intervals. When the window is open, the two filter covers for supply and exhaust air are visible and can be opened with the aid of a flat head screwdriver. Some pressure must be exerted towards the frame.
The procedure is described in detail in the Internorm operating and maintenance manual.

After servicing the filters, press the + and - button on the Internorm control panel simultaneously for at least 5 seconds to confirm the maintenance and reset the warning.

Frost Protection

The Internorm itec Ventilation unit has its own frost protection. If the internal temperature of the ventilation unit is too low the device will stop. When the unit is in this state manual control is currently not possible. Below a temperature of -20°C the ventilation unit will be displayed as disabled via the system status. Depending on how it has been installed this frost protection may already kick in a lot sooner. Due to technical limitations it is unfortunately not possible to display this. Further information about the frost protection of the ventilation unit can be found here.