OK, did two butts over the weekend. When I get a chance to get on the home computer pics will follow. The point here is that with 35 degree weather it still took me two hours to get my Super Pro (with mods) up to temp. Using Royal Oak lump for fuel with small pieces of oak (roughly 1 inch diameter, 3-4 inches long) dispersed throughout. Temps dropped to between 200 and 220 once meat went on. Struggled all day until I decided to add some Kingsford briquettes I had on hand after I went through a large bag of Royal Oak. Took almost 16 hours to complete and that was with finishing in a 240 degree oven! Now I used to work in large power houses. Everything got preheated. Combustion air gets preheated by the waste gas going to the stack. Feedwater gets preheated by the flue gas on its way to the stack. Feedwater also gets preheated by steam after use on turbines. Even the coal is heated to about 140 degrees as it is ground up in the pulverizers before going to the furnace. The $64,000 question is: Has anyone tried to raise the temperature of the combustion air before it gets to firebox for cold weather smoking? I had a "vision" of bringing some ducting material that would run from the end of the smoke chamber by the side shelf, under the smoke chamber, under or behind the firebox and turn the corner to the air inlet. By doing this you would raise the temoerature of the combustion air thereby raising the temperature of the burnt gases going thru the smoker. What are the thoughts out there? I am no tinknocker or metalsmith, but I think the idea has merit.