I am nearly finished with my watt burner and was wondering if a 4" air intake with a 4" vent is big enough for a smoker that is 3'x3'x51/2'. I am hoping the air intake is large enough cuz that part is already done:whistle: The exhaust vent can be changed yet but doesn't seem to make sense to have a vent larger than the intake. Also, will a 1000 watt burner be large enough to get my temps up or should I put in 2 1000 watt burners.

I can't comment specifically on the size... but I DO figger the air intake on wattburners is NOT near the same size as on traditionally fired units, as little combustion air is needed.

Vertical or horizontal....? Rich is right about the combustion.

Vertical or horizontal....? Rich is right about the combustion.
Vertical......3' wide x3' deep x 51/2' high

You don't need any air flow as far as combustion is concerned, obviously no true combustion going to occur. You will need some for venting out humidity, to help even out temps, and as a thermo control if you are not using a t-stat or PID type controller. I have a freezer conversion and my outlet is 4 in. and intake is only the air pulled from gaps in the door and my smoke generators. It seems about right. I have a 1500 watt Brinkmann element which works well with a thermo from Allied-Kenco. If you are very well insulated, 1000 watts might be enough, but can't ever hurt to have more. Particularly for recovery times, and warm ups.

Jim, attached here is an Excel file that calculates sizes on different smoker functions;

Ken, do ya think we could get this located into a tutorial someplace. Seems like I am reposting this fairly often anymore.

Does it consider wattburners? And yes, you do need some intake with them. Not much, I suppose but it can't be a sealed box.

You don't need any air flow as far as combustion is concerned, obviously no true combustion going to occur. You will need some for venting out humidity, to help even out temps, and as a thermo control if you are not using a t-stat or PID type controller. I have a freezer conversion and my outlet is 4 in. and intake is only the air pulled from gaps in the door and my smoke generators. It seems about right. I have a 1500 watt Brinkmann element which works well with a thermo from Allied-Kenco. If you are very well insulated, 1000 watts might be enough, but can't ever hurt to have more. Particularly for recovery times, and warm ups.

The box is 2x6 construction w/6" insulation. I am using a PID controller and have a small squirrel-cage fan ducted from top to bottom to move air.

Well.... I will gently disagree. The chips need to "burn". But it's very little needed. It is more important to have some airflow for the humidity and "old smoke" to vent. Look at it this way...you can make the exhaust pretty large, and have a damper for the input... and tweak :{)

Hello Rich I don't know if that calculator takes into consideration watt-burners. But as has been stated, you don't need much intake anyhow, just enough to get some chips or chunks to smolder. Its all about exhaust and getting that excess humidity and smoke out. I think you resplved it all the way around when you suggested just a little bit bigger size and toss in a damper.

Well.... I will gently disagree. The chips need to "burn". But it's very little needed. It is more important to have some airflow for the humidity and "old smoke" to vent. Look at it this way...you can make the exhaust pretty large, and have a damper for the input... and tweak :{)

I am not burning chips inside the smoker, I have a smoke generator I have attached to it. Like I said before, the 4" air intake is already built into the floor with a slide damper. Do you think it will benefit to put in a 6" exhaust?

Also thanks davidmcg for the file, but for some reason I can't open it.

I am not burning chips inside the smoker, I have a smoke generator I have attached to it. Like I said before, the 4" air intake is already built into the floor with a slide damper. Do you think it will benefit to put in a 6" exhaust?

Also thanks davidmcg for the file, but for some reason I can't open it.

Ahhh... well, heck if that's the case... I can't see needing 6". I mean ya COULD, but I got a feeling you'd be mainly dampering it. I dunno what the smoke production/output of the gen is either. Might be some advantage to have more exhaust? Hell, I'm learning here too... ;{)

I am assuming the smoke is warm enough for convection to carry it up and out tho, and sure seems a 4" intake is huge. But then again it is a big cab.