Florida Journeyman Practice Exam

The maximum outlet temperature limit for warm air in a plenum supplied by a furnace is set at 265°F. This temperature limit ensures safe operation within the heating system, minimizing the risk of fire hazards or damage to ductwork and surrounding materials.

The 265°F threshold is established based on safety codes and industry standards that take into consideration the materials typically used in constructing plenums and ducts, as well as the thermal tolerances of insulation around these components. Operating above this limit can result in excessive heat that may compromise the integrity of the plenum or lead to hazardous conditions within the building.

Maintaining the outlet temperature within this specified limit allows for efficient heating while protecting the home and its occupants from potential dangers associated with high temperatures, such as combustion of surrounding materials or overheating of the system.