Duct Insulation
When houses or heating/cooling systems are renovated, insulation is added to existing ducts, because it can be cheaper than replacing the ducts. The potential for energy and cost savings can be significant, particularly when adding insulation to poorly insulated ducts. Even when ducts are inside the living (conditioned) space these conduction losses can be important because the losses from long duct runs can lead to rooms being uncomfortable because they not receive enough heating or cooling.