Yes, propane is dangerous. But, so is gasoline and even diesel fuel. If you maintain a diligent check for leaks, you will not have any problems. Plus, you can smell leaks because of the stinky stuff that is put in propane.
In the winter, there is low humidity. That causes dry air which can lead to dry flaking skin. Many people use a humidifier in the winter. The small amount of "moisture" that emanates from a propane catalytic heater is minimal, and is a useful thing in the winter.
I refer you to some info that I wrote in my thread about propane catalytic heaters.
Well, let's talk about them heaters for a bit, shall we?
Propane catalytic heaters are made up of a fibrous pad that is platinum strands. It looks similar to a steel wood pad.
Now, somehow magically, when the platinum fiber strands mix with a fuel source (propane) and oxygen, it produces a "glow heat".
The heaters are 97% fuel efficient and they do not have to be vented. You must, however allow for some oxygen intake from one of your windows.
The reason that they are 97% fuel efficient is because the fuel never combusts. In all combustion systems, whether it be automobiles or heating systems, there will be a carbon monoxide output.
On regular furnace type heating units, 30% of the heat value goes up the chimney (or, vent in the case of motorhomes). Those are the carbon monoxide exhausts from the combustion process.
With propane catalytic heaters, the only exhaust is carbon DIOXIDE, which is what we humans exhale, and water vapor.
Carbon dioxide is a non poisonous gas. When someone tells you to talk to your plants, it is because all plants strive on the breath you exhale while talking to them. The water vapor is also welcomed by the plants.
You may turn on many types of heaters in your abode, and you may notice how long it takes to warm the place up. That time frame is different with each type of heating mechanism.
I had a wood stove in my 64 International. I was living in Connecticut and doing carpentry. When I got home from work on a cold winter's day and the wood stove had died perhaps around noon that day, my bus was almost refridgerator temperature.
So I would load it up and keep my winter clothes on for an hour watching the flame and anticipating when it would be warm enough to play guitar. An hour later, I could remove some of my garb, but it was not for another hour that it would be warm enough to move my fingers on the guitar.
I love wood stoves, but for them to be a primary source of heat, they need a tender.
The great thing about a propane catalytic heater is that it is a radiant heater. It heats the mass of objects as opposed to heating the air. So start it up, sit in front of it, and instantaneously, it is like you are sitting in front of a fireplace. Those heat rays seek you out.
These types of heaters were developed in 1929 by the French. They wanted to develop a heater that they could use while working around airplane engines. It needed to safe as to not ignite the engine fuel.
Being that the catalytic action works at a significantly lower temperature, there is not enough temperature to ignite a combustion.
I have three of these 3000 BTU propane catalytic heaters. On low setting they put out 1000 BTU, on high, they put out 3000 BTU. The way your bus is insulated, it would be easy to heat it up with these heaters. You can also get larger heaters up to 8000 BTU.
They are called Safety Heaters because if, for any reason, the glow from the pad stops, a thermobulb will trigger a spring that shuts off the flow of propane. I have never had the glow stopping. From what I understand, that could only happen with a sustained flow of air across the surface.
They are silent, unlike RV furnaces that need 12 volts to drive the fan blower.
I have used my catalytic heaters while driving my my vehicles.
Here is a pic of one of mine.