Premix Burners

Premix burners use a machined mixing-set and forced air from a blower or compressor. There are two basic types: open and sealed. Open premix burners use a steel or cast iron retention-tip. Sealed premix burners use a return intake (RI) castable tunnel or a multi-port (MP) tip mounted into the furnace wall. Natural gas or liquefied petroleum (LP) gas may be used at low pressure since the forced air induces the gas and produces a blast-type flame.

Premix burners are more efficient than atmospheric burners. They provide greater control over the air and gas mix, and produce hotter air. Sealed premix burners do not require wasteful secondary air. Open premix burners need secondary air for cooling purposes, and to prolong the tip's life and complete combustion. Some operators trade tip-life for lower noise and lower capacity by using fiber to seal the tip in the furnace port.