The answer, of course, is, it depends. Your QuitCarbon contractor should be able to tell you whether or not, and why, you need to replace your ducting to have a comfortable and efficient heat pump experience, and the goal of this article is to help you understand the factors that will go into their decision.
The most obvious reason you would benefit from new ducting is if your current ducting is in bad shape. While some ducting can be brought back to reasonable shape with some sealing, you’ll be better off replacing more decrepit ducting.
The other reason you’ll benefit from duct replacement and modification is if your current ducting won’t provide enough airflow to keep you comfortable with a heat pump. A major advantage of a heat pump over a furnace is that it heats your home with a low and slow heat (and cooling!), modulating down to run extra efficiently when your rooms reach the desired temperature. In order to push out this low and slow heat, your heat pump may need to push more volume of air than your current ducts can accommodate. This higher volume of air may be accomplished with some minor modifications and air balancing, or it may require duct enlargement (return or supply), additions, or a full system replacement. In general, homes with ducts designed for air conditioning are more likely to have ducts that don’t need any modifications, or relatively minor ones.
Going beyond need, you may prefer to upgrade to ducts with additional insulation, for greater comfort and efficiency.
Lastly, some homes are built in a way that upgrading ducts is very challenging or not practical. An example of this would be where a duct going to a room is buried in an undersized vertical shaft. There are solutions for these situations, for example adding a ductless unit for a specific zone of the home, or adding a second air handler to the attic to reach the rooms on the top floor.
QuitCarbon appreciates that all homes, homeowners, and budgets are different. We aim to connect you with the best contractor for your situation, that can address these differences to deliver a comfortable heat pump experience.