The hvac_duct element is a child of the hvac_distribution element. You can submit up to 3 instances of the hvac_duct element for each hvac_distribution instance.


  • The name element must be submitted in order to identify the correct instance of hvac_distribution

  • The sum of the fraction values for all three instances must equal 1

  • The following heating and cooling types must have a distribution system: central_furnace, heat_pump, gchp, split_dx