What should be done to ductwork that runs through unconditioned spaces?

Ductwork that runs through unconditioned spaces should be insulated primarily to prevent energy loss and maintain the efficiency of the heating and cooling system. In unconditioned areas, such as attics or crawl spaces, temperature fluctuations occur, which can cause the air in the ducts to lose heat in winter and gain heat in summer. Insulation helps to minimize this temperature change, ensuring that the air delivered to living spaces is at the desired temperature.

Insulating the ductwork also helps to improve the overall energy efficiency of the HVAC system. When ducts are insulated properly, they reduce the amount of energy required to condition the air, which can lead to lower utility bills. In addition to energy savings, insulation can also help prevent condensation on the duct surface, which can lead to mold growth or further damage over time.

While sealing ductwork can be beneficial, insulation in unconditioned spaces specifically addresses the temperature loss and ensures the system operates efficiently. Painting ductwork does not provide any insulating benefits, and removal of the ductwork would not be a practical solution unless the system configuration is being completely modified. Thus, insulating ductwork in unconditioned spaces is the most effective action to maintain efficiency and prevent issues related to temperature fluctuation.