Catalytic (e.g. Olympic Wave 3) and ceramic (e.g. Portable Buddy) heaters have some very specific advantages and disadvantages. Their main advantage is they are very, very efficient at heating your trailer. The advantages they offer are 1) they use no battery
or electric power (they are entirely propane
powered), 2) less heat is lost because they burn their fuel and release all hot combustion gasses into the trailer (furnaces vent combustion gasses and heat outside the trailer), and 3) because the combustion process makes water vapor that raises the humidity in the trailer, the heat that is produced feels slightly
Their disadvantages are that 1) they do not circulate the air in the trailer, so trailer heating is very uneven, 2) you have to leave a pair of windows
or vents slightly cracked to provide fresh air, 3) they make water vapor, which condenses on cold surfaces (like your windows) and run down the walls.
I do not consider safety to be a huge issue with these heaters. We have a lot of people using them here, and no one has come back to tell us they died because of a heater malfunction.
Back to being serious again, both catalytic and ceramic wall heaters and their portable cousins like the Portable Buddy are certified as safe as long as you adhere to the ventilation requirements, which are really quite modest and easy to follow. I've run our Portable Buddy as a sole heat source and thought it did a great job. (I've also run it and discovered some problems, which is part of a story I'm telling in this forum.)
Forced air furnaces have their advantages and disadvantages, too. On their advantage side, they have blowers that distribute the heat more evenly around the trailer, they have igniter circuits or pilot lights
that allow them to be thermostatically controlled rather than set to burn steadily at "High/Medium/Low," so you get better temperature control, and they don't vent water vapor into the trailer, so there is less (not none: people vent wate into the air as they breathe, and that creates condensation, too) condensation on the windows
On their disadvantage side, they are heavier, noisier, and less efficient. Catalytic heaters weigh about a third as much as a furnace
, furnaces typically pull around 3 amps or more when they run, which can be problematic when you're dry-camping, and more than a third of the propane's heat is lost, vented to the outside of the trailer with the combustion gasses. (The "Everest 8200" is the most efficient of the forced air heaters, and draws about 1.8 amps, btw.)
What will work for you? That you have to decide, but it's definately a topic of discussion for us because we like to dry camp with our trailer, and we have run our battery
down because the furnace
draws so much power. We're just not sure whether the answer is installing a catalytic heater or trading our existing furnace
out for an Atwood Everest 8200.