AUTODRAFT TEMPERATURE CONTROL

In barbecue, controlling pit temperature is nearly as important as controlling smoke quality.  Many factors (e.g., wind, rain, meat load) influence pit temperature, but the biggest driver is the amount of heat transferred from the fire/burner/element to the cooking chamber.

All common pit types share one key attribute: 100% of the power produced by the fire goes into the cooking chamber.  As long as controlling the fire power is easy, as in Charcoal Cookers and Electrics & Gassers, there's no problem controlling pit temperature.  But a wood-fired pit (a.k.a. a Stick Burner) is a totally different animal:

• We learned in The Fire Triangle that a fire's power will be limited by fuel if we have good (hot) geometry and surplus of air to avoid making Creosote.
• We learned in How Wood Burns that wood ain't fuel.  It's a fuel source, which produces two fuels (smoke and charcoal) as it decomposes under heating.  From a control standpoint, that is a huge difference.

This means that the power of a clean-burning wood fire (and the temperature of your pit) is determined by the rate of decomposition of wood into charcoal and smoke.

Huh?!?!

Right about now, you should be experiencing a growing sense of awe for the True Pit Boss.  Some people can build a clean-burning wood fire.  Others can build a wood fire that keeps the pit steady at X degrees.  Few can do both at the same time, because that demands a thinking process that is a full step ahead of the current pit temperature. The True Pit Boss gages when to add a log based on its size, shape and moisture content, the temperature of the fire itself, the state of decomposition of the logs already in the fire, coming changes in meat load and weather, etc., etc.  And the only calculator he has is the pattern recognition capability gained from an enormous amount of experience. Many of the best barbecue joints don't even have a thermometer on the pit - the boss just controls the size of the fire from memory and feel.

Karubecue technology removes this experience barrier by disconnecting the fire's power output from the pit's power demand.  The fire is always supplied with surplus air.  Good, hot geometry is always maintained by the IFF.  Because the IFF intrinsically controls smoke quality over the full demand range - from shutoff to 100% power - temperature control is easy:

AutoDraft replaces the traditional smokestack with a fan that draws air from the cooking chamber and discharges it overboard.  When the fan runs, it draws a slight vacuum in the cooking chamber, which in turn draws hot smoke from the IFF, inverting the flame to ensure good combustion.  When the fan cycles off, the fire reverts to normal, with no heat entering the cooking chamber.  The fan is controlled by a simple thermostat, which regulates temperature in a tight control band.