With the little bit of experience I have I would say always fill the upper racks. During the Break-in period and the first time smoking I noticed the center of the lowest rack about 5F below the center of the top rack. Perhaps the upper racks will have better smoke and heat distribution being a little farther from the water pan which only allows smoke and heat to rise from the sides.
Interesting! Thanks, Oillogger. My smoke for today is washed out...literally! Very heavy thunderstorms since daybreak and still coming! I have several oven thermometers and will place them about the racks when I fire up next. Thanks!
Sorry to hear your day was a wash-out...that line of storms is supposed to be heading down this way..got something quick for the grill...
When I just use one shelf...I usually try to put in the middle....really just for convience...you are going to be monitoring the smoker temps at that shelf anyway...so it shouldn't matter which position you use....with your vents set for a good draft...the amount of smoke should be fairly equal in any of the positions....just my $.02
Richard has it, as long as you use thermometers, it really doesn't matter where the rack is. However, my recollection is that the upper portion of the smoker usually gets warmer than the lower positions. Therefore, optimally speaking, upper would be better (more efficient). But there is a lot to be said for convienence and room to operate. AKA..... use what you like but use your thermometers.
Was going to chime in, but seems everybody else already stated it. Makes no difference, as long as you are monitoring the temps at the shelf level. The other part of the equation becomes your personal preference.
I never realized it, till my wife pointed out I always move the fire to the left side, and cook on the right when I am going for indirect on the weber. Half of what I do is because somebody told me to do it that way, the other half is because I read it somewhere, then there is the 1/2 that I do, just because it is comfortable.