When it comes to renovating any space, personal or professional, the list of things you have to keep in mind is a long one indeed. Planning changes to the ductwork design of your HVAC system may not necessarily be first and foremost on your mind. Nonetheless, it is something you will absolutely want to keep in mind. This is something that should be dealt with as early on as possible.

Failure to do so can be problematic for several reasons.

Is Your Air Conditioner As Efficient As It Could Be?

Even if you aren’t planning a renovation, there is a good enough chance that your HVAC system isn’t as efficient as it could be. For a wide range of buildings and properties, this can mean some or all of the following issues:

  • Annoying hot/cold spots.
  • Impeded airflow creating drafts, indoor stuffiness.
  • HVAC system aging faster, as it has to work harder.
  • Poor-to-dangerous indoor air quality.
  • Unbalanced air pressure, which can cause problems with odors and noises.

Chances are, your ductwork design is to blame. In renovation situations, failing to consider the changes to your HVAC system will definitely lead to some of the possibilities highlighted above.

Common AC Ductwork Design Mistakes

Whether you are planning some renovations, or simply want to maximize the potential of your HVAC system, it really all just comes down to proper ductwork. Let’s take a closer look at 5 of the most common ductwork design pitfalls we have encountered:

  1. Poor Sizing: Undersizing is perhaps the most common ductwork design mistake we’re aware of. You can have the most powerful HVAC system in the world. If your ductwork is too small to deliver what your system offers, the performance is going to be substandard. Furthermore, we are talking about a type of performance that will degrade your system more quickly.
  2. Elbows poorly placed: An elbow will always slow down airflow. It is your responsibility to consider a design that will use as few as humanly possible. Remember that too many sharp bends/turns can dramatically decrease the amount of air the space receives.
  3. Leaks: This is another common pitfall to keep in mind. Correct sealing and support are essential with good ductwork design practices. Even one or two air leaks can cause your system to work harder for less in the way of results.
  4. Materials: It should go without saying that if you want the best possible finished product, you want to use the best possible materials and tools to achieve that end.
  5. Return vents: Return vents are essential at making sure the air in the room is pulled back into your HVAC system. Failing to address this right from the start can create comfort issues for everyone in short order. Return air supply should not be restricted in any form or fashion.


Choosing the best location, creating a detailed load calculation, and making sure to use the right supports and fittings are a few key examples of good design practices. Trusting professionals can also be invaluable.