just what part is the baffel...is that wher the air tubs are? i just got one but not hooked up yet...where does the air supply enter to fuel the fire...i cant seen to find anywhere...how do the air tubs work...i didnt get a book with mine cause it was 50% off...what is a cheap replacement when the brick ware out...thin red brick or regular 1 inch concret?...thanks all for your help...