Tjernlund PAI-4 Combustion Air In-Forcer

The Tjernlund PAI-4 Combustion Air In-Forcer delivers a dependable combustion air supply for commercial heating systems. This unit supports multiple firing types with capacities of 450,000 BTU/hour for gas draft hood, 850,000 BTU/hour for fan-assisted/power burner, and 775,000 BTU/hour for oil-fired flame retention, ensuring optimal draft and safe operation.

With an air flow rate of 250 CFM, it provides ample outside air to keep burners running efficiently even in tight or poorly ventilated spaces. Its compact footprint measures 20 inches long, 12 inches wide, and 9.5 inches high, and it includes a mounting integral bracket for simple wall or roof installation. Ideal for commercial applications, this unit ships with a fan proving pressure switch and an outdoor air pre-filter for clean, consistent air intake.

• Combustion air in-forcer for reliable burner draft in commercial applications
• Wide capacity range: 450,000 BTU/h gas draft hood; 850,000 BTU/h fan-assisted/power burner; 775,000 BTU/h oil-fired flame retention
• Air flow 250 CFM ensures consistent combustion supply
• Compact dimensions 20" L x 12" W x 9.5" H with integral mounting bracket for wall or roof installation
• Includes fan proving pressure switch and outdoor air pre-filter for safety and air quality