7 Signs You Need Air Duct Repair (and When to Replace Instead)
Hot rooms, high bills and a dusty house often trace back to a leaking duct in the attic. Here is how to tell, and when to replace.
Air duct repair is one of the least visible and most effective fixes in a Texas home. Your ducts run through an attic that can pass 130 degrees in summer. When one leaks, the cold air you paid for goes into the attic instead of your bedroom.
How much air do leaky ducts waste?
ENERGY STAR estimates that in a typical house about 20 to 30 percent of the air moving through the duct system is lost to leaks, holes and poorly connected ducts. In San Antonio that loss happens in the hottest part of the house, so the AC works harder for longer.
7 signs you need air duct repair
- Some rooms never cool down. A room at the end of a long run, or over the garage, stays hot while the rest of the house is fine.
- Energy bills climb with no change in how you use the AC.
- The AC runs almost nonstop on days it used to keep up easily.
- The house is dusty soon after cleaning. Leaky return ducts pull attic dust and insulation fibers into the system.
- Weak airflow from one or more vents.
- Whistling, rattling or banging in the ceiling when the system starts.
- Visible damage in the attic: flex duct that is crushed, kinked, torn, sagging on the insulation, or pulled off its collar.
What does air duct repair involve?
Most problems are fixed in a single visit. Leaks at joints and seams are sealed with mastic, which holds up far better in attic heat than ordinary duct tape. Disconnected runs are reattached and strapped. Crushed or torn sections are cut out and replaced, and flex duct is supported so it stops sagging. After the repair, air reaches the rooms it was meant for.
When is replacement the better choice?
Repair makes sense when the damage is limited to a few spots. Replacement is worth pricing when:
- The outer jacket is brittle and cracking in many places.
- Leaks and disconnections are found throughout the system.
- Ducts are badly undersized for the rooms they serve.
- You are replacing the AC system or remodeling and the layout is changing anyway.
- There has been pest or water damage throughout the attic.
Fix the ducts, then clean them
Leaky returns pull in dust, so a house with duct damage usually has dirty ducts too. The best order is to repair first and clean after, so the clean system stays clean. Pair it with attic insulation if the attic is also under-insulated, and your AC finally gets a fair chance.
Related reading and services
See air duct repair and installation, HVAC repair and attic insulation, or read whether attic insulation lowers energy bills.
Air duct repair
How do I know if my air ducts are leaking?
Rooms that never cool, rising bills, a dusty house and weak airflow from some vents are the most common signs. An inspection of the attic ductwork confirms it.
How long does air duct repair take?
Most repairs are finished in a single visit. Larger replacements take longer, and we confirm the timeline and price before starting.
Is duct tape good for sealing ducts?
Ordinary cloth duct tape breaks down in attic heat. Mastic sealant, or foil tape rated for ductwork, lasts much longer.
Should I repair or replace my ductwork?
Repair when the damage is limited to a few spots. Consider replacement when the ducts are brittle, leaking throughout, undersized, or you are replacing the AC system.
Can leaky ducts make my house dusty?
Yes. Leaks in return ducts pull attic dust and insulation fibers into the system and blow them into your rooms.
