Question: In my research I've noticed that catalytic stoves have a bypass damper for use while loading so that smoke doesn't roll into the room. It seems that very few non-cats have this bypass damper. Assuming proper draft, will I regret not having this kind of feature or is smoke during loading not usually a problem with non-cat stoves? Just looking to avoid the smoke ring on my ceiling Thanks! Answer: Catalytic stoves have bypass dampers because the catalyst will not function until it is brought up to operating temperature. If you force the smoke through the catalyst before it is up to "light off" temperature, it can clog the cells in it. Most Non-cat stoves don't have bypass dampers because they are not necessary. It is probable that any non-cat stove with a by-pass damper on it has it because it needs it. All woodstoves are tested to UL-1482 standards. Part of that safety standard is a smoke roll out test that tests for smoking when the doors are open. If the stove smokes more than a slight wisp with the door(s) open, the stove fails the test. It's that simple. My experience of 24 years in the stove industry has been to stay away from non-cat stoves that have by-pass dampers. Reason being that it is just one more movable part to repair as the stove progresses in age. The less things to go wrong with a stove, the better off you are down the road a few years. That's just my opinion.