I've been using cats for years. First in campers and now in an AS. I have a wave 8 for AS. There are a few issues with cats that you should know. The combustion process generates water, lots of it! the humidity in an enclosed space can be a real pain. I've found a way to totally eliminate it though. Sorry I don't have pics, but I'll try to explain. I had a sheet metal guy fabricate a "chimney" for the heater. It is an aluminum box that is slightly larger than the top of the heater (about 1" wider and 1" deeper) and extends up the wall above the heater. The top of the box is closed and the bottom which sits even with the top of the heater is open. Hopefully you can visualize this. At the top you need to have a small port to the outside, like maybe a 1" tube running from the top of the box through the wall or ceiling. You don't want more than that because you will just lose heat. The box will get hot and radiate heat into the room so you want it away from where you might bump into it. You can also get aluminum gril material from any ace hardware and build a grill around the chimney. This set-up totally eliminates the moisture problem while still capturing nearly all of the heat! Cats are great IMO. They are very efficient, dead quite, and safe. Because they do not have fans, I use a 12V
muffin fan, like the ones used in computers, but 12 volt
, to circulate heat. The muffin fans use just milliamps of power and are very quiet and long lived. With the chimney fix and the muffin fan recirculater, the cats do a great job of heating for all but the most extreme conditions. I have camped in my camper at 7 below zero with the smallest cat you can buy.
My AS will have a mini wood burning stove and the cat back-up. No other furnace. I really enjoy the quiet.