Looks like they come with an exhaust to vent outside via whatever means
here are some pictures of the installed heater in the van
The kits come with everything you will need including a 10 litre fuel tank
I did get an extender for the 'zorst as I wanted to to end further away than the standard one allowed
And underneath the heater
The black pipe is the combustion air intake, the silver is the exhaust .. comes out the bottom of the unit and then exits the locker to right under the van
The diesel is fed through the small tube via a filter and pump into the bottom of the unit
I have the fuel tank mounted in a locker in the van
In the workshop It will be wall mounted.
It can be 3 or 4 yards from the heater, or 3 or 4 inches
A couple of picture clearly showing how efficient it is. Note the start time , inside and outside temperature