Main parts

R model in the figure. In the L model, the parts are mirrored.

No.PartNo.Part
2aHeat recovery cell6bAdditional heating resistor (behind the extract air duct)
3aExtract air fan (behind the protective cover)7aSafety switch
3cSupply air fan (behind the protective cover)9aCeiling bushing for electric wires
4aFine filter for supply air10aControl panel
4bCoarse filter for supply air11aInternal carbon dioxide and humidity sensor
4cCoarse filter for extract air11cCarbon dioxide sensor (optional)
5aBypass damper of the HR cell11dHumidity sensor (optional)
6aPost-heating resistor (behind the extract air duct)11eVOC sensor (optional)