How to check ductwork before buying

Check visible ductwork for disconnected runs, crushed flex duct, rust, missing insulation, and past repairs. A leakage test and room-by-room airflow readings tell you how the system actually performs.

Inspect the visible ducts

If you have access to the attic, basement, or a utility closet where ducts are visible, you can do a basic visual scan without touching or opening anything:

Look for obvious damage. Crushed, disconnected, or sagging duct sections are visible problems that usually mean poor airflow to the rooms they serve.
Check for exposed insulation or missing sections. Ducts that are bare metal or flex duct with torn insulation in an unconditioned attic can be losing conditioned air before it reaches the room.
Note duct age and material. Older ductboard or flex duct that looks brittle, crushed, or heavily patched with tape is worth asking about.
Look at connections at the air handler or furnace. Gaps, loose duct straps, or obvious tape-and-patch repairs at the main trunk are a visible sign that the system may have leakage issues.
Check for rooms that never feel right. If you’re already living in the home or touring during a showing, note any rooms that feel noticeably hotter, colder, or stuffier than others—this can hint at duct or airflow problems in that branch.

None of this tells you how much air is actually leaking or whether the system is sized correctly for the home. It’s a screening step, not a diagnosis.

What the inspection should verify

Actual duct performance—leakage rate, airflow at each register, and whether the system was sized and installed correctly—needs testing equipment and training that a homeowner walk-through can’t replicate. According to ENERGY STAR’s guidance on quality HVAC installation, ducts should be evaluated with an actual leakage test, and system airflow should be checked against the equipment manufacturer’s performance specifications rather than judged by feel or a “rule of thumb” for sizing (ENERGY STAR). Refrigerant charge is another item on that same list that only a contractor can verify with proper tools.

If you’re seriously considering a home, ask the seller or your inspector whether a duct leakage test has ever been performed, and consider hiring a qualified HVAC contractor to do one before or shortly after closing. ENERGY STAR points to the Air Conditioning Contractors of America’s accredited contractor list as one way to find someone who offers this kind of quality-installation testing (ENERGY STAR).

Local permitting and inspection records

In New Orleans, HVAC work—including duct replacement or major repairs—typically requires a permit through the city’s Mechanical Division. You can check a property’s permit history to see whether past HVAC work was pulled and inspected through the city’s permit search tools, which is a reasonable step before buying, since it shows whether prior duct or system changes were done under an inspected permit rather than informally (City of New Orleans, Department of Safety and Permits).

Putting it together

A visual walk-through can flag obvious red flags—damage, missing insulation, disconnected sections—but it can’t quantify leakage or confirm the system is right-sized for the home. Treat what you see as a reason to ask more questions, not as a final verdict. For a real answer on duct condition, a licensed contractor’s leakage test and airflow check, done before or soon after purchase, is the only way to know what you’re actually buying into.

For more homebuying guidance on home systems, see the homebuyers section.

Sources

HVAC Quality Installation | ENERGY STAR, accessed 8/12/2026
Products and Tools | FEMA.gov, accessed 8/12/2026
Safety and Permits - Home - City of New Orleans, accessed 8/12/2026