Recently acquired a nice food warmer. Bout 6' tall by 20" wide and 26" deep. Primarily going to use it for cold smoking but I have a propane burner, and if temps are high enough I may use it as a hot smoker as well. My question is, the guy I bought it from had the same basic idea as me. He cut a hole in the top and placed a nice chimney on it with a baffle. Problem it, it's maybe 3" diameter, very small for the size of a cabinet. I'm very familiar with calculating chimneys and such for offsets and rf's but not quite sure how to go about it with the vertical style. Is this chimney big enough? I'm going to get at least 1 maybe 2 vents for the sides at the bottom. I'll be using an Amazn smoke generator for cold smoking. Maybe a cast iron skillet on the burner if I hot smoke. Let me know what you think.