Supercharging the Englander 30...Project OverKill.

Huntindog1 said:

Making the firebox smaller by adding more bricks should make the stove more efficient just like smaller stoves are more efficient. Plus adding thermal mass is good as it will store heat for you and slowly radiate it out later. The stove with more mass will heat up slower.

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One thing to keep in mind though is that IFB's will lower thermal mass. By nature they resist heat. They prevent heat absorption and keep the heat in the fire chamber. Standard firebricks are the opposite. They heat up more slowly and act as thermal mass. Kind of like soapstone. Actually some people do replace their firebricks with soapstone.

In the pizza oven trade the inside of the oven is lined with standard firebricks, as they tend to hold the heat in. Then there is a layer of IFB's to prevent the heat from escaping the oven. It takes longer to heat up but maintains level heat longer. Click here for a better description on a pizza oven hobbyist site.

By putting IFB's in our fireboxes we improve fire start up and initial secondary production. The heat is kept in the fire instead of getting absorbed into standard firebricks. This makes the fire get hotter quicker and secondaries fire off quicker. After the fire is established and the stove is up to temp it probably doesn't matter which brick you have. The IFB's should help get you up to temp quicker and allow you to turn down your air quicker.

A stove with standard fire bricks is losing some btu's to the bricks at first in order to heat them up. This shows why larger secondary stoves like the Englander 30 take longer to get into the cruise zone when compared to smaller that are more insulated. But one can probably argue that the larger stove with firebricks will stay a little warmer after the fire has gone out due to thermal mass.

IMO IFB's are probably best suited for secondary stoves, especially larger ones in order to get them in the cruising zone sooner. By nature secondary stoves do not stay hot for prolong periods of time (compared to cat stoves) and heat cycle more often. I think firebricks (or even soapstone) are best suited for cat stoves since they maintain a relative constant temp longer.

Huntindog1 said:

Which brings me to another idea that was given to me by a guy who sells ITC-100 and is in the Kiln and forge business. Now this would be a more expensive mod but interesting to think about. He said he gets calls from those professional meat smoking guys. They are always trying to build a better smoker. He said what they are trying is not using fire brick to line the fire box but like 1/2 plate steel. He said in a wood stove you could try the same thing and cut you pieces of 1/2" Plate steel. This will add mass to you stove which will store much more heat and re-radiate out the heat long after the fire goes out. So since you are using 1/2" Steel in place of the fire Brick you can use a thicker 1" ceramic Kawool insulation back behind the 1/2" steel for insulating the fire box.

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I'm a BBQ enthusiast and we like to keep temps constant for LONG periods of time. Like 12-18+ hours for big cuts of meat like briskets, pork shoulders, hams, etc. We hate temperature fluctuations. The goal is to keep the internal temp the same even if the fuel source (charcoal, wood or propane) has minor temperature output fluctuations.

The thick steel plate will add thermal mass and once heated up it will help keep temps constant. The IFB's behind the steel plate prevent the heat from being lost outside the smoker. This concept is perfect for a cat stove in my opinion.

The steel plate would also be preferable for smokers because it is easily cleaned...which typically needs to be done before every smoke. Since its operating at 225 degrees and cooking food instead of much higher temps found in wood stoves...you tend to get grease and soot build up fairly quickly. This would be a pain to clean if you used firebricks or some other porous material.