In looking at various smoke cookers large enough for concessions it seemed that regulating heat was a problem when the doors were opened and closed during cooking. It ocurred to me that the recovery time could be shortened and total cooking time decreased if a exaust fan was put in-line on the chimney and used briefly following opening of the door. The draw of air would increase the fire box heat and pull a burst of heat back in and recover the loss. Ash could probably be kept from being sucked into the pits by several methods if it became an issue. When time counts, but tending the meat is necessary, doesn't it make sense to improve preformance. Or am I missing something here? I note that one company claims the high temperature seal around their doors decreases heat recovery time by retaining the smoke and heat.