What additional requirement applies when installing duct heaters near a heat pump?

When installing duct heaters near a heat pump, one critical requirement is that the installation must include proper listing and labeling for the duct heater. This ensures that the equipment has been evaluated and approved by a recognized testing agency for safety and performance under the specified conditions. The listing and labeling provide important information on installation, usage, and compliance with local codes and standards, which is particularly vital when integrating different types of heating equipment such as a heat pump and duct heater.

Adhering to this requirement helps to mitigate risks associated with electrical and thermal hazards, ensuring that both systems operate safely and efficiently together. This is especially significant in residential and light commercial settings where safety and compliance with building codes are paramount.