An air handling unit (AHU) for a heating, ventilation, air conditioning, and refrigeration (HVACR) system includes a housing and a combustion heater disposed within the housing. The housing includes a combustion section with a first channel and a second channel. The combustion heater includes heat exchanger tubes and a tube support that supports heat exchanger tubes within the combustion section. The tube support slidably disposed in the first channel and the second channel. The combustion heater configured to be slidably removable from the AHU. An AHU for an HVACR system includes a housing with a fan section and a fan assembly disposed within the housing. The fan assembly including a pair of grooves slidably disposed on a pair of rails of the housing. The fan assembly configured to be both slidably removable from the AHU and liftably removable from the AHU.

The fingerprinting system includes a main body, an air movement source, an ignitor, and a hydrocarbon fuel source. The main body includes a handle. The air movement source includes a fan. The air movement source is coupled to the main body. The fingerprinting system is configured to burn the hydrocarbon fuel source to produce soot containing carbon. The air movement source is configured to direct the soot containing carbon toward a surface to be analyzed for fingerprints.

Burner for a reforming reactor including an oxidizer pipe arranged coaxially within a process gas annular channel, wherein the nozzle has a trumpet-like shape and the lip of the nozzle has a wave or sinusoidal profile.