Northern Tool Heavy Duty Burner question...

Drilling new holes in the current configuration still leaves you with a possible propane bomb.....  But, do what you wish.....  We can't force you to do things in a safe manner, only point out the deficiencies in your design...  Install a flame sensor so the propane shuts off when the flame goes out....

Man killed when meat smoker explodes

Colleen Kottke, The (Fond du Lac, Wis.) Reporter 4:49 p.m. EST December 15, 2014

(Photo: The (Fond du Lac, Wis.) Reporter)

TOWN of LAMARTINE, Wis. — A Wisconsin man using a homemade meat smoker to cook turkeys and chickens died when the smoker exploded, police said.

Richard L. Zabel, 55, was found dead Saturday afternoon inside a machine shed.

"The North Fond du Lac Ambulance and Lamartine first responders were called to the scene for the initial report that someone had fallen," said Lt. Cameron McGee of the Fond du Lac County Sheriff's Office. "When investigators arrived on scene, they discovered that a 55-year-old man was dead inside the building."

Zabel, a town of Lamartine man, did not live at the building's location, but lived nearby.

"Evidence indicates that the flame on the LP burner went out and as a result the gas continued to accumulate inside the smoker," McGee said. "And when (Zabel) went to relight the burner, the spark from the lighter caused the gas to explode."

McGee said the force of the explosion caused the heavy duty door of the smoker to blow open, striking Zabel in the head, killing him instantly.

"When something explodes, it's going to blow open at the weakest point which was the door, which was triple-latched," McGee said.

McGee said the smoker was larger and better constructed than most store-bought models.

"It was about 4-feet tall and about 3-feet wide and built really solid, including the door. Someone really put a lot of thought into building this thing," McGee said. "We were told that they had been using it for the past three years without any problems."

The Fond du Lac County Sheriff's Office is investigating the incident.

Well, I wouldn't want the entire bottom of the smoker open... Gas smokers are no more dangerous than a gas grill. Common sense goes a long way, but you can blow yourself up with either.

If you're going to use holes, make them decent size. 2" or more would work. Or make something like a 6" opening below the burner.

My Masterbuilt 44 inch has a 9.78 cubic foot cabinet. The 'as built' hole in the bottom is 8" X 14". That's 112 square inches. The exhaust flue I installed in the top is 6 inches in diameter. That's 28 square inches, one quarter of the bottom opening. I can throttle the exhaust by means of the damper I installed in the flue.

I'm just sayin'.....

No Sir, can't help you with any ratios.

I installed the 6 inch flue in top of my smoker because the original vents only equated to a 2, 1/2" diameter hole. Not NEARLY enough. I put a damper in the flue so I could choke it if I wanted. That has paid off as there have been situations where a wide open 6 inch flue was too much exhaust.

When fuels gas is burned, the cubic feet of exhaust is greater than the combined cubic feet of air and fuel gas prior to ignition. I would rather have a bigger inlet to avoid starving the fuel of air.  And, with a nice big exhaust outfitted with a damper, you can always choke it down for whatever reason.

With the burner you have the air intakes are inside the CC with the burner. If you look at mine, combustion gas and air is supplied at the rear of the burner which is open to air. You need to make sure your burner is getting plenty of air so I would drill more holes in the bottom, near the gas inlets. Better yet would be to section it off from the CC entirely.

Switch the therms position...   the therms aren't reading the same...

I wouldn't worry about 5 or 10 degrees difference anyway.