Question: I want a heater for my RV so I can sleep in my RV in the winter months.
Answer: What kind of heater to use in your RV really depends on several factors. Start by thinking of whether you will be hooked up to power or will you be using the heater while dry camping (no hookups). Then you have to decide if you want a radiant, convection, combination heater.
Use a radiant heater to warm people or objects. They quickly heat but you have to be directly in front of the heater for best effects. Caution: They can burn you if you touch them since they stay hot to the touch.
Use a convection heater to slowly heat a room. They heat the air around them and provide heat that rises and causes cooler air to fall to the ground. The heater will be warm or hot to the touch but is safer than a radiant heater.
There are many types of combination heaters. They all use a fan to force air over a heated element and use electricity.
Another specialized heater is a propane powered catalytic heater, which would fall under the convection category.
Once you've what whether you need the heater for camping while hooked up or dry camping here are a few suggestions:
Best choice but expensive – A catalytic propane heater like Olympian Wave or Camco catalytic heater. They use propane and do not need to be vented. Caution: Since these burn propane and need air you should leave a window or vent cracked open to prevent carbon monoxide poisoning.
Use the furnace that came with your RV, just watch how much battery power you use or you might discharge your battery and end up getting very cold.
Hooked up to power:
Buy an electric heater or several. I have used catalytic electric heater for years because of their small size. One is almost ten years old and still working well. You may need to manage your electric power usage since they get plugged into a regular outlet. If you attempt to run more than one heater off the same breaker you may overload the breaker. They are fairly quiet but you can hear the fan. They are much less noisy than a furnace blower.
Another popular option is a convection heater. It creates heat by heating a liquid which then radiates heat into the air. Think of baseboard heaters you find at home. The best things about convection heaters are that create little or no noise while in use, provide good even heat and are very efficient. They have two drawbacks one is their size (in my opinion too large for an RV) and they do take a while to heat a room.