Woodstoves 101. Not sure I should be the guy to do this, but here goes. Also not sure what you mean by bends, but I have always noted that the more bends there are the more opportunity for creosote build-up and more opportunity for fires. Creosote builds up when unburned or inefficiently burned gases and debris cools in the chimney and resolidifies on the sides. After a while you can get enough of a buildup that ignites via spark or high heat. The resulting fire can be quite intense. If the fire is not contained to the chimney, obviously bad things happen. To reduce the risk of chimney fires, you first burn dried and aged wood. You will also want to clean the chimney. This involves running a brush down the chimney which cleans all of the accumulated debris off of the walls. A stainless steel liner gets a poly brush (shaped just like the flue) which can be run down through the chimney with fiberglass poles that screw together every three or four feet. Masonry liners get a metal brush.
When you clean a chimney, all of that debris will need to go somewhere. With a masonry chimney, you will often find a clean-out at the base of the chimney, usually below the point of where the woodstove's vent pipe enters the flue. This way the debris passes the woodstove and can be easily cleaned out. It is a dirty job. Add that dirt to the dirt that you will drag in with the firewood and you may end up with an unhappy Donna-ski.
Another concern that I have is that with the size of that room, even a very small unit will probably heat up fast and darn near chase you out of the room.
You may want to consider a wood pellet or corn stove or propane gas ventless logs as these units require little if no venting. The pellet stoves have a fire burning inside, you can view it through the glass, and it still looks good. Some vent via a PVC pipe through the wall. Again, not all models are the same and I am no professional.
I am not a heating professional. I have very little experience with pellet stoves. We have ventless propane logs in our second floor family room and appreciate the convenience and the cleanliness as compared to a wood fire up there. When we stoned the chimney from the first floor to the ceiling, we had the stone guys build a faux fireplace on the second floor. It has not vent but you wouldn't know it at a casual glance. There may even be a picture in the habitat threat somewhere.
As for our woodstove, we have 6 plus acres of hardwoods here and I burn a lot of firewood in a year. We only burn dead stuff. I also cut firewood from other people's places when I have an opportunity. We burn about 10 cords a year, which is a lot of wood. We heat our entire house with a wood boiler hooked into a hydronic heating system. It is a good, even heat but it requires a lot of work. Keeps me in the outdoors, anyway. We permanently mounted a ladder on the roof (steep roof) to make it easier to clean. I clean ours about once a month, but we get more buildup because it is a boiler. Long story. Anyway, that is what I know about woodstoves. Please keep asking I am will continue my loquacious ways.
