Model A B C Inlet Diameter CFM Motor HP Motor Amps Motor Volts

Standard

16" 16" 18" up to 8" 250-750 1/8 1.5 120
Large 21" 21" 24" up to 12" 750-1500 1/2 5.0 120

Selection for Gas & Oil Applications: Sea Level Atmospheric with Draft Hood

Model Vent Pipe Diameter BTU/Hour Input Max Pipe Length at 400°F Stack

Standard

8"

400,000-700,000 100'
  8" 700,000-900,000 50'
  8" 900,000-1,100,000 25'
  10" 700,000-1,000,000 100'
  10" 1,000,000-1,200,000 50'
  10" 1,200,000-1,300,000 25'
Large 12" 1,000,000-2,000,000 100'
  12" 2,000,000-2,400,000 50'
  12" 2,400,000-2,600,000 25'
  14" 2,000,000-2,500,000 100'
  14" 2,500,000-2,700,000 50'
  14" 2,700,000-2,900,000 25'

Selection for Gas & Oil Applications: Sea Level Fan Assisted/Power Burner with Barometric Draft Conrol

Model Vent Pipe Diameter BTU/Hour Input Max Pipe Length at 400°F Stack

Standard

8"

500,000-900,000 100'
  8" 900,000-1,200,000 50'
  8" 1,200,000-1,400,000 25'
  10" 500,000-1,000,000 100'
  10" 1,200,000-1,500,000 50'
  10" 1,500,000-1,700,000 25'
Large 12" 1,200,000-2,700,000 100'
  12" 2,700,000-3,200,000 50'
  12" 3,200,000-3,500,000 25'
  14" 2,700,000-3,500,000 100'
  14" 3,500,000-3,700,000 50'
  14" 3,700,000-3,900,000 25'

*Important: Select the auto drafter based on the BTU/hour input of the appliance(s) rather than the diameter of the appliance(s) vent outlet or chimney. Vent/Chimney sizes listed are the smallest inside diameter recommended for the associated BTU/hour input. Use a tapered reducing collar or transition fitting if the vent is reduced to the pipe diameter listed in selection table. To determine equivalent feet, add the total length of straight vent pipe plus 10 feet for each 90° elbow and 5 feet for each 45° elbow.