Heating is indispensable, so you need fuel. There is a choice of propane, LPG or diesel. Propane is okay, but in almost all European countries the tanks are different, so for every country you need a different tank. This is not practical. LPG is more easy, however, officially you are not allowed to fill the tank yourself, again not practical. So for me the most practical solution was a Planar diesel heater, a cheap version of the Webasto heater. The great advantage is that the heater can be directly connected to the dieseltank of the van through the float lid. I watched several You Tube movies before I dare to do it. I can recommend it, it is worth the while.
Heater, hot air canals, diesel pump and connection through the bottom floor for air intake and outlet of combustion gases.
Diesel hose going in the direction of the diesel tank and electric cables to the monitor panel on the wall and to the battery. The diesel tank can be approached from beneath the cabine floor through the float lid of the tank.
Intake of air (black) and outlet of combustion gas.
Complete outlet hose for combustion gas (outlet of dirty water tank next to it)