Coal Stoker Outputs:
It is an accepted engineering industry standard that you can only effectively burn 50lbs of coal
per square foot of stoker head per hour. This accepted standard and the Btu value of the coal
being burned effectively limits the "Btu input" of a stoker head.

Keep in mind not all stoker heads are equal! Depending on the construction of the head the
"actual surface area" that is available to burn the coal is not the same, on a cast iron
stoker head and ash ring you will typically loose 2-1/2" of "actual surface area",
on a steel head and ash ring you will typically loose up to 4-1/2" of "actual surface area".

i.e. a 16" cast iron stoker head (13.5") has an actual surface area of .994 square feet and can
effectively burn only 49.7 pounds of coal per hour. If the coal being burned has a value of 8000 Btu
per pound the maximum "Btu input" of the stoker head is 397,600 Btu. The problem is you
have to know the efficiency of the appliance burning the coal in order to determine "Btu output".
If the appliance is 60% efficient, the Btu output on this 16" head would be 238,560 Btu.

A good example of all stoker heads not being equal is in comparing the CF-2000 22"
cast stoker head and ash ring which has an "actual surface area diameter of 18", to the Portage
& Mains 23" stoker head and layered steel ash ring that has a "actual surface area diameter of 17"

A manufacturer's product literature can make their product look like it has a larger Btu rating
then a competing manufacturer's product - when in fact it actually has a smaller Btu output!