Do You Need New Ductwork With a New AC System?

If you're preparing to replace your air conditioner, you might be wondering whether your existing ductwork is still good—or if it needs to be replaced, too. It's a common and important question, especially for homeowners in Hillsboro, Oregon, and surrounding areas where many homes have aging duct systems. While replacing your AC can improve comfort and efficiency, neglecting old or poorly designed ducts could hold your new system back.

At Aviator Heating & Cooling, we help homeowners make informed decisions about air conditioning installation, and that often includes evaluating the condition of their ductwork. In this post, we’ll break down when duct replacement makes sense, what signs to look for, and how proper duct design affects long-term comfort and energy costs.

The Role Ductwork Plays in Cooling Efficiency

When it comes to air conditioning performance, your ductwork plays a far more critical role than many homeowners realize. The efficiency, comfort, and longevity of your HVAC system depend not only on the air conditioner itself but also on how well your duct system delivers cooled air throughout your home.

Ducts are essentially the distribution network for your cooling system. If that network is damaged, poorly designed, or undersized, your new high-efficiency AC system won’t be able to perform to its full potential. In fact, the U.S. Department of Energy estimates that typical duct systems lose 20–30% of the air due to leaks, holes, and poorly connected ducts—especially in older homes.

What Happens When Ductwork Is Compromised?

Outdated or improperly functioning ductwork creates a ripple effect across your entire HVAC system. Common issues include:

• • Uneven temperatures throughout the home: Rooms farthest from the air handler may be too hot or too cold due to airflow restrictions or pressure loss.
  • Rising energy bills: When air escapes through leaks or has to travel through undersized ducts, your AC system runs longer and works harder to reach your desired temperature.
  • Increased strain on your AC unit: Overworking the system can lead to frequent breakdowns, shorter system lifespan, and more frequent service calls.
  • Noisy operation and poor humidity control: Undersized ducts or sharp turns in the layout can cause whistling, rattling, and improper moisture removal, which is especially noticeable during Oregon’s humid summer days.

In short, your ductwork and air conditioner are a matched system. Installing a modern, energy-efficient AC unit without ensuring the ductwork is properly sized, sealed, and balanced is like putting a new engine in a car with a failing transmission—you’ll still struggle to get optimal performance.

Why It Matters During an AC Replacement

Many homeowners assume they only need to upgrade their air conditioner to improve home comfort. But if the duct system was designed for an older, less efficient unit—or if it has deteriorated over time—simply replacing the AC won’t solve deeper issues with airflow or distribution.

At Aviator Heating & Cooling, we perform ductwork evaluations as part of every AC installation in Hillsboro and surrounding areas. This ensures that the entire system—not just the equipment—is optimized for efficiency, performance, and longevity. We assess the condition, layout, and airflow capacity of your existing ducts and offer honest recommendations, whether that means duct sealing, minor upgrades, or a full duct replacement.

For homeowners looking to maximize energy savings, improve indoor comfort, and protect their investment, making sure the ductwork is up to par is a critical part of the project.

Signs You May Need New Ductwork With Your AC Upgrade

Upgrading your air conditioner is a smart investment—but if your ductwork is outdated or poorly designed, your new system won’t perform as expected. Ducts are responsible for distributing cooled air throughout your home, and when they’re compromised, you can experience comfort issues, high energy bills, and premature system wear.

Below are five signs that your ductwork may need to be replaced or upgraded when installing a new AC system.

1. Aging Ductwork (15–20+ Years Old)

Duct systems typically last between 15 and 25 years. As they age, they often develop leaks, loose connections, and airflow restrictions.

Common issues with older ducts:

• • • Metal ducts may rust or corrode
    • Flexible ducts can sag, tear, or collapse
    • Joints and seals may weaken over time

Why it matters:
Old ducts may not handle the airflow demands of a modern high-efficiency air conditioner. Leaving them in place during an AC upgrade can limit system performance.

What we do:
At Aviator Heating & Cooling, we assess duct condition during every AC installation and recommend replacement when it's necessary for long-term comfort and efficiency.

2. Physical Damage, Mold, or Rust

Visible damage or contamination in your ductwork can lead to poor airflow, compromised air quality, and increased health risks.

What to look for:

• • • Dents, holes, or crushed sections
    • Rusted joints or discolored insulation
    • Moldy or musty odors when the system runs
    • Signs of pests or water damage

Why it matters:
Damaged or contaminated ductwork reduces system efficiency and may allow pollutants to circulate through your home.

Our recommendation:
If damage is widespread, full duct replacement is often more cost-effective—and safer—than patchwork repairs.

3. Uneven Temperatures Throughout the Home

Inconsistent temperatures in different rooms often point to poorly designed or unbalanced ductwork.

Symptoms of airflow issues:

• • • Hot upstairs rooms, especially in the summer
    • Cold spots in corners or lower levels
    • One room always more uncomfortable than others

Why it matters:
Even with a new AC system, you won’t experience consistent comfort if your ducts can’t distribute air evenly.

How we help:
We regularly assist Hillsboro and Beaverton homeowners by adjusting duct layouts, improving balance, or adding zoning systems for room-by-room temperature control.

4. High Energy Bills With No Clear Cause

If your energy bills remain high even after installing a programmable thermostat or upgrading insulation, your ductwork may be the reason.

How leaky ducts cost you:

• • • Wasted cooled air escaping into attics or crawlspaces
    • Longer AC run times
    • 20–30% energy loss in severe cases

Why it matters:
Leaky or unsealed ductwork forces your new AC system to work harder, driving up monthly utility costs.

Our approach:
We offer duct testing, sealing, and replacement as part of our AC installation services to ensure peak efficiency and comfort.

5. Undersized or Poorly Installed Ducts

Older homes in Forest Grove, Aloha, and Tigard often have duct systems that weren’t designed with today’s HVAC standards in mind.

Problems with undersized ducts:

• • • Poor airflow and pressure imbalances
    • Loud airflow noises from vents
    • Frequent system cycling and shorter equipment lifespan

Why it matters:
New high-efficiency air conditioners require properly sized ducts to function as intended. If airflow is restricted, even a great system can underperform.

What we offer:
We perform load calculations and airflow assessments during every installation. If ductwork is undersized or inefficiently routed, we’ll recommend solutions like resizing, rerouting, or full system upgrades.

Should You Replace Your Ductwork When Installing a New AC?

Your new air conditioner is only as effective as the ductwork it relies on. If your ducts are outdated, leaking, or improperly sized, they can limit the performance of even the most efficient AC system—leading to higher energy bills, uneven comfort, and premature system wear.

At Aviator Heating & Cooling, we help homeowners throughout Hillsboro, Beaverton, Tigard, Forest Grove, Aloha, Lake Oswego, North Plains, and Sherwood get the most out of their AC investment by evaluating the entire system—not just the equipment. That includes taking a close look at your ductwork to ensure it's supporting your comfort and efficiency goals.

When Duct Replacement Makes Sense:

• • Ducts are over 15–20 years old
  • You’re experiencing hot/cold spots or airflow issues
  • The duct layout was designed for outdated equipment
  • There’s visible damage, rust, or signs of mold

In these cases, upgrading or replacing the ductwork along with your new AC system often delivers better long-term results and energy savings.

When You May Not Need New Ductwork:

There are situations where your existing ductwork can be reused—especially if:

• • It’s in good condition and less than 15 years old
  • Airflow is even and balanced in every room
  • It’s already properly sized for your home and new AC system
  • You’ve kept up with maintenance and periodic duct inspections

Even if a full replacement isn’t necessary, we often recommend duct sealing, cleaning, or insulation upgrades to maximize your system’s performance. These improvements can significantly reduce energy loss and improve indoor comfort without the need for major construction.

Whether your ductwork needs minor adjustments or a full overhaul, Aviator Heating & Cooling will give you honest recommendations, detailed assessments, and expert installation—so your entire HVAC system performs the way it should.

What We Do During an AC Installation

At Aviator Heating & Cooling, we don’t just swap out your old air conditioner. We evaluate your entire HVAC system, including ductwork, thermostat, and airflow requirements, to ensure everything works together.

Our process includes:

• • Performing a full ductwork inspection and pressure test
  • Recommending duct sealing, repairs, or upgrades if needed
  • Verifying system compatibility with smart thermostats or zoned controls
  • Ensuring your new AC is properly sized and matched to your home’s layout

We aim to deliver long-term comfort, energy efficiency, and peace of mind—not just a quick installation.

Proudly Serving Hillsboro and Surrounding Communities

We provide AC installation, ductwork services, and HVAC system replacements across:

• • Hillsboro
  • Beaverton
  • Tigard
  • Forest Grove
  • Aloha
  • Lake Oswego
  • North Plains
  • Sherwood

Whether your home is new or decades old, our team will help you decide whether duct replacement is necessary for your AC upgrade—and provide honest recommendations based on your home’s unique needs.

Ready for a Cooler, More Comfortable Home?

Before investing in a new air conditioner, make sure your duct system isn’t holding it back. At Aviator Heating & Cooling, we’ll assess your current ductwork, recommend smart upgrades, and install your new AC the right way—ensuring peak performance and energy savings.

Call us today or request a free estimate online. We proudly serve Hillsboro and surrounding communities with expert AC installations and full-service ductwork support.