If your HVAC system seems to run longer than it used to or your energy bills have crept up without any significant lifestyle changes, the issue could be hiding in your ductwork. Leaky air ducts can quietly waste energy and weaken your comfort without you even noticing at first. The sooner you catch the problem, the easier it is to fix. Liberty Comfort Systems in Anoka, MN, helps homeowners figure out what’s going wrong behind the walls and ceilings, where most ductwork lives.
Detecting Leaky Ductwork
When air trickles out of leaky ducts, your HVAC system works harder. That strain manifests in uneven heating or cooling, higher energy bills, and wear on your equipment. You may notice some rooms feel warmer or cooler than others, even after running the system for hours. A few holes or loose seams in the ductwork can cause this imbalance.
Finding those problem spots takes a sharp eye and a few simple tests. Use your hand to feel for airflow while the system is running, or pay attention to drafts near walls and ceilings where ducts are located. Catching those leaks early means you can seal them easily and restore consistent airflow throughout the house.
Smoke and Thermal Tests Reveal Hidden Gaps
When you want to hunt down leaks you can’t see, using smoke or thermal imaging can help. Light, visible smoke from a stick or source not tied to fire safety will drift toward gaps in the ducts. That movement tells you where the hidden holes may lie. Thermal imaging works differently by displaying temperature differences in real-time.
If a duct passes through an attic or crawl space, the thermal camera will highlight warm air escaping in winter or cool air leaking in summer. These tests highlight trouble spots that would otherwise go unnoticed. Without this kind of insight, you could seal the wrong places and leave leaks untouched.
Pressure Testing and Duct Blowers Show You the Amount of Air Lost
Pressure testing steps up the inspection by formally measuring leakage. A duct blower attaches to a supply register and pressurizes the entire duct network. This instrument provides a precise reading of the amount of air that escapes. The setup typically runs for fifteen minutes with the blower pushing air in while the HVAC system is off. A good reading means only small leaks.
A high reading indicates significant airflow loss, resulting in wasted energy and higher bills. That data helps you decide how aggressive your sealing strategy should be. It also sets a baseline against which you can test after repairs to confirm improvements.
Inspecting Dust Connections, Joints, and Crimps Matters
Most leaks occur where ducts intersect or bend. Joints in fittings, flex duct crimps, or seams in rectangular duct sections can separate or crack. In older installations, these connectors may lose tape or mud over them. In unfinished spaces, rodents or movement can damage connections. That loose fit lets conditioned air escape before it reaches your rooms. You’ll want to examine each run from the furnace or air handler to the supply registers.
Notice where fiberglass duct board meets uninsulated duct, where dampers open and close, or where branching occurs. Any loose collar or punctured section offers an opportunity for air loss. Once tightened, resealed, and supported, those runs deliver air where you expect it.
Sealing Ducts Can Give Immediate Comfort and Savings
Using mastic sealant or metal-backed tape, you can lock up those leaks. Mastic is a thick paste applied around joints, seams, or small holes. After it dries, it forms a flexible but durable air and moisture seal. Metal-backed foil tape works too, especially for rigid ducts. Avoid cloth or duct tape, which quickly degrades.
When you seal a joint properly, you’ll notice an improvement in airflow in that room. That extra airflow makes the air handler cycle less often to hit the thermostat setting, which cuts energy use. You can run the system more smoothly, with fewer on-off cycles that stress the compressor. Over time, this also reduces wear and tear on your equipment and helps you stretch the life of your HVAC system.
Cleaning and Insulating After Sealing Boosts Results
Once you’ve sealed all visible gaps, adding insulation matters in unconditioned areas like attics or basements. Duct insulation helps maintain temperature as air travels from the supply to the registers. Without insulation, cool air warms up in summer or heated air loses warmth in winter while passing through hot or cold spaces. That temperature shift can fool your thermostat into running longer than needed. R-value rated insulation reduces that loss. If dust buildup in ducts already holds moisture, cleaning before sealing prevents mold growth after you seal in moisture. The sequence you follow matters: clean, seal, then insulate. That order cleans your system, locks in airflow, and maintains air temperature so each run feels balanced and efficient.
Balancing Dampers Helps You Fine-Tune Flow
After sealing and insulating, you may notice new airflow strength in some rooms. That might result in colder or louder air in areas previously starved of supply. Balancing dampers help you fine-tune that flow. Those small adjustable plates in duct branches let you throttle airflow to each zone. For example, after sealing leaks, you might reduce the damper for the main living room to match bedroom airflow.
That keeps airflow even and ensures sensitive areas, such as a nursery, don’t experience excessive cold or heat. Balancing involves making small adjustments and conducting brief test runs. You adjust the damper, measure airflow, repeat, and tune until every room feels right at your thermostat setting.
When to Call a Professional In
Some duct problems go beyond what a homeowner can safely fix. Large holes, collapsing ducts, or duct runs inside walls or floors may require professional help. Technicians bring the right tools, like duct blowers for pressure testing, specialized sealants for flexible duct, or replacement sections for badly damaged runs. They can also spot systemic issues like undersized ducts, poorly designed layouts, or insufficient return air.
These issues reduce performance even if there are no visible leaks. A professional installation provides documentation on both before-and-after performance, including energy savings and airflow improvements. If your home struggles to maintain comfortable temperature or humidity levels, that assessment provides insight before spending money on a new HVAC system.
Keep Your Ducts Healthy With Regular Inspections and Maintenance
Even after sealing, ductwork needs attention every few years. Shifts from settling, attic renovations, or rat activity can introduce new leaks: insulation ages and sealant cracks. A regular check of supply registers, return grilles, and visible duct runs prevents leaks from growing unnoticed.
Early detection of small tears, damp spots, or dust plumes can prevent phantom energy losses. Set a reminder every three to five years to monitor system health. You’ll avoid losing air and energy cycle after cycle. Ductwork acts like the circulatory system for HVAC, pumping air throughout your home.
Schedule Your Ductwork Inspection Now
Spotting a duct leak early can prevent more significant problems down the line, especially if your system has been struggling to maintain efficiency. Consistent airflow and even temperatures start with a solid duct system, free of gaps or weak connections. Along with duct repair, ductwork cleaning, and we also conduct insulation checks and air quality improvements to help your entire system operate more efficiently.
If you’re ready to stop losing heated or cooled air to hidden leaks, schedule an AC maintenance inspection today with Liberty Comfort Systems.
