Duct heaters located within how many feet of a heat pump or air conditioner need to be listed and labeled?

Duct heaters that are installed within a specific distance from a heat pump or air conditioner must be listed and labeled to ensure safety and compliance with the mechanical code. The distance of 4 feet is established as a standard requirement because installation within this proximity can affect both the electrical and mechanical operation of the heating and cooling systems.

The labeling and listing of duct heaters are crucial to confirm that the equipment meets performance specifications and safety standards appropriate for use near other HVAC components. This is to mitigate risks such as overheating, electrical hazards, and interference with system efficiency. By adhering to this 4-foot requirement, professionals ensure that installations are conducted safely and in accordance with regulations, maintaining the longevity and effectiveness of both the duct heater and the heat pump or air conditioning system.