"Ductwork doesn't often get a lot of consideration because it seems boring and unremarkable. However, in any HVAC system, the ductwork is a crucial component. Do some research on one of the two following topics: • What could happen, or has happened, as a result of consumers replacing their older HVAC systems with energy-efficient ones without modifying or replacing ductwork? Did any problems arise, or did the existing ductwork function adequately? • What types of modifications to or replacements of ductwork have consumers made after installing an energy-efficient HVAC system? Why did these consumers choose to make these modifications or replacements? Were they pleased with the results? Provide specific details about the topic you chose."