These duct heaters are not intended for installation in series in the air.
Electric duct heater installation.
Duct elbows or turns must be located at least 4 from the inlet of the heater and 2 from the outlet of the heater.
Installation instructions 47 66kb download document tubular element heaters.
Custom built electric duct heaters are safety tested and listed by underwriters laboratories ul and the canadian standards agency csa and meet national electric code nec requirements.
Warren heaters are engineered for reliability and safety and are specifically designed not to exceed safe operating temperatures.
Never operate a duct heater without airflow.
Sufficient working space must be provided per paragraph 110 26 of the nec.
Warren technology produces custom built electric duct heaters for installation in commercial hvac systems.
Rh series electric duct heaters installation operation and maintenance manual.
Installation instructions 47 66kb download document thermo air.
The heater must always be interlocked with the fan.
Instruction manual 66 13kb download document.