The product BAPL-6339 has a description of BLAST 360 DIRECT FIRED PORTABLE HEATER
Diesel direct-fired portable heaters with embedded burner with
combustion air obtained from the main air fan. The Blast heaters
generate hot air and the combustion residues produced by the burner are
expelled with the hot air and contribute to its heating. They transform
all of the nominal input power (from the fuel) into heat, 100%
Can be used only in well ventilated rooms and where indirect-fired heaters are not required by law.