Hi, I'm looking for help with my kiln design. I am having trouble getting it to temperature most of the time. It is ceramic fiber, cylindrical, approximately 50 c.f. and propane fueled with a 500 gal tank. I don't have the exact btu available, but I believe it is more than enough, with a single burner. I primarily fire it with a saggar, which is made of hard brick, also cylindical, that sits and fits exactly on a 26" round shelf. The fire box is about 4 inches tall, made of soft brick, which supports the fiber shell. The gap between the bottom shelf and the wall varies between 3 and 4 inches while the gap between the saggar wall and shell is about 3.5 inches. The gap between the top of the saggar and the roof can vary from between 3 and 7 inches, with little difference noted in performance. It generally peaks out at about 1800 deg., however when it windy, I can get it up to 2200+ without any trouble, so obviously there is an air flow issue. I have experimented with innumerable combinations of vent and intake size, including a flue, although most of the time I haven't had a flue. It seems once I get the vent large enough, I just start losing heat. Is my only solution a blower? My other thought is to rebuild the roof so that it is more of an arch. Any help is very much appreciated. Thanks.