The genius of the Propex heater is that it separates the creation of heat from the delivery of heat into your vehicle. This precludes fumes and condensation in the heated cabin area. The heaters create heat by burning propane in a combustion chamber and then exhausting the resultant fumes through a stainless steel exhaust pipe. The heater installation kit comes with a silicone gasket that is rated far in excess of the temperature the exhaust produces that isolates the exhaust pipe from the vehicle.
If you're concerned with hot exhaust piping being an issue or would just like to have further protective insulation, we offer a vulcanized fiberglass sleeve that will insulate the exhaust pipe along it's entire length. Both can be found at www.vancafe.com. Order blue heat shield for HS2000 and HS2211 installations and red for HS2800 installation.