Catalytics work great but they have a big drawback - water. I have one in my 20' camper. If kept running for long periods of time, you'll have water running down the windows. On a hunt a few years ago, it was so cold that we had to keep it running during the day to keep the water from freezing. After 3 or 4 days of steady burning, our matches were too damp to strike and we had ice on the insides of all the windows. All of our clothes and bedding felt damp, too.
