Evening Paul... I know folks that drill holes in their smokers like yours... Air flow is very important for good clean smoke flavor... I'm not a fan of exhaust in the top... condensate can drip on the food... One suggestion would be to insert 1" pipe nipple in the top of the side walls... 1" pipe is 1.05 ID.. I would put in 2 to start.. one each side on opposite corners... then you can add 2 more if you think air flow is lacking...
For the
AMNPS, think about lowering the drip pan 3" if you can and add "walls" to 3 sides... Add legs to the
AMNPS..
1-1/4" bolts to raise the
AMNPS 1".. that will give you 1/2" clearance to the smoker floor with the
AMNPS in the drip pan.. You probably will have to drill a few more holes in the floor..
Now, the AMNPS is getting plenty of fresh air... no grease dripping on it... the only drawback is creosote may not condense out like it does in the Mailbox and flex duct..
If you can elevate the smoker body and drill a 3" hole in the bottom for a 90 deg. elbow to transition to flex and MB, that would eliminate other headaches... If the floor is sloped to allow for drainage, keep the 3" hole on the high side so drippings go in the pan and not the elbow.... With the flex, elbow and MB, getting the smoker up about 12" would make like easier... If you have any questions about my thinking, don't feel alone.. stand in line.... Dave
PS... now you need more exhaust holes...