Internorm Ventilation

The Internorm function blocks controls an Internorm fan based on Humidity, Temperature and CO2. When using a Motion Detector, different ventilation speeds can be defined dependant on presence detection. If desired, various special functions such as Sleep, Turbo, and Exhaust Air can be activated via the User Interface as well as via function block inputs.
If air-dependant fireplaces are in the fan’s area of influence, a negative pressure can draw smoke into the living area!


AbbreviationDescriptionUnitValue Range
HiInternal Humidity. If humidity exceeds parameter Hmax, the ventilation will increase. If this input is not connected, humidity is not taken into account.%0…100
CO2Internal Air Pollution. If CO2 levels exceed the parameter CO2max, ventilation is increased. If this input not connected, air pollution is not taken into account.ppm0…∞
TsOutside Air Temperature. Indicates the temperature of the incoming air. Used for Temperature functionality. If this input is not connected, the value of the System Variable “Outside Temperature” is used. If this is also not available, all Temperature Functionality is disabled.º
IwWindow Contact (ON = Window Open, OFF = Window Closed). If a window is open, Ventilation is disabled.Digital0/1
MvMotion Sensor Input. The overrun duration must be configured using parameter TH.Digital0/1
StSTOP. Stops the fan while input is activeDigital0/1
SIDigital Input – Sleep Mode: Turns off ventilation for the time set in parameter TSl. Afterwards, the block will start again with ventilation.Digital0/1
TbBOOST. Stops all control and sets the output to 100 percent.Digital0/1
ExExhaust Air. Stops all control and exhausts air at 100 percent. ATTENTION: This input can only be used if the block property “Exhaust Air / Supply Air Operation Permitted” is activated.Digital0/1
RFAcknowledge Filter Change. Resets the filter warning. Should be activated after a filter change. (This Input is not available for all configurations)Digital0/1
REAcknowledge Error. If there is an active Internorm Error code, it will attempt to restart the fan. (This Input is not available for all configurations)Digital0/1


AbbreviationDescriptionUnitValue Range
AQsAnalogue 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: Manually Stopped, 5: Window Open, 6: Manual Boost, 7: Manual Control User Interface, 8: Manual Exhaust Air, 9: Sleep Mode.0…9
QftFilter Change. Indicates whether air filters need to be changed.Digital0/1
QeError: Indicates if there is an error: 0 = No Error, 1 = Offline, 2 = Apertures Closed, 100-115 = Internorm Error code.


AbbreviationSummaryDescriptionUnitValue Range
HmaxMaximum HumidityMaximum Humidity Limit: The block tries to keep the Internal Humidity level below this value.%0…100
CO2maxMaximum Air PollutionMaximum Tolerable Air Pollution: The block will always try to keep the Internal Air Pollution level below this value.ppm0…∞
THMotion Sensor OverrunOverrun timer, which starts with the falling edge of the motion detector. Extends presence by the specified time spans0…∞
TSlSleep Mode DurationOverrun timer, which starts with the falling edge of the sleep input. Keeps the device off for a specified period of time.s0…∞
ViIntensive Ventilation During AbsenceIntense Ventilation During Absence. At Humidity levels above Hmax or CO2 levels above CO2max, the fan will operate at this strength. In Temperature mode, this value is used as the maximum.%0…100
VBasic Ventilation During AbsenceBasic Ventilation During Absence. Fan operates at this level in automatic mode when absent. In Temperature mode, this value is used as the minimum.%0…100
VPiPresence Intensive VentilationIntensive Ventilation During Presence. At Humidity levels above Hmax or CO2 levels above CO2max, the fan will operate at this strength. In Temperature mode, this value is used as the maximum.%0…100
VPPresence Basic VentilationIntense Ventilation During Presence. Fan operates at this strength during automatic mode when present. In Temperature mode, this value is used as the minimum.%0…100
TOOverride TimeOverride Time: The buttons on the Internorm fan start override timer for this period. (This Parameter is not available for all configurations)s0…∞


Exhaust Air / Supply Air Operation PermittedSets 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!
Ventilation Direction (without heat exchanger)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 FanFan 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. Futher information can be found here.

Maintenance/Filter Change Interval

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. The filter cover can be opened with either a fingernail or with the aid of a flat head screwdriver. Some pressure must be exerted towards the frame. More detailed information on maintenance can be found here.