For use downstream as a medium or high temp burner on 1750 RPM centrifugal fans. Not for use as a low temperature burner. Specially designed burners are adjustable for uniform heating temps with a choice of liquid propane, propane vapor or natural gas. Available for GSI 1750 RPM (10-40 HP) centrifugal models, the downwind centrifugal burner is capable of capacities up to 4.2 million BTU/hr.