Heating a van is dictated by the type of van and the purpose of the heat. For example, heating a family van or minivan means turning on and adjusting the auto's heater. A cargo van may need a heater placed in the cargo area to keep the contents warm. A conversion (also known as a camper-van) van requires a heater that warms the camping and sleeping quarters without draining the oxygen in the confined space.
Turn the van on and let the engine warm up. Turn the heater to "On".
Adjust the fan to circulate the warmed air throughout the cabin. If the van has rear heaters, turn those on to push warm air into the back.
Crack a window or turn the fan down to bleed heat out or help relieve condensation on windows.
Purchase a small portable camper heater that is AC/DC powered. Be sure the AC power is done through a cigarette lighter plug for the van.
Place the heater in a location near the bottom of the van and away from fabric or hanging curtains. Turn the heater on when sleeping, or camping in the van.
Crack at least on window when sleeping with the heater on to prevent asphyxiation.
Use the portable heater as in Section 2. Position the heater away from any cargo, flammable fabrics or goods. Secure the heater to the floor of the van via retaining screws.
Turn the heater to a medium temperature and close the cargo van doors. Use a medium setting as the enclosed space will begin to retain the heat during long transport trips.
Use batteries in the heater in the cargo van as this alleviates the need to drill holes in the panels to run an adaptor plug to the cigarette lighter in the van cab.