If one room in your DC home never gets comfortable while another is always stuffy, the problem usually isn't your furnace or AC at all. It's the ductwork carrying the air between them. The U.S. Department of Energy estimates that the average home loses 20 to 30 percent of its conditioned air to leaks, holes, and poorly connected ducts. Ducts running through attics and crawlspaces tend to be the worst offenders, often shedding more than 20 percent of the air on their own before it ever reaches a vent.
Washington's older row houses and converted homes are especially prone to duct trouble. Systems get retrofitted into tight chases and stairwells, runs are undersized for the square footage they serve, and decades-old seams loosen over time. The result is the same set of complaints we hear across Capitol Hill, Petworth, Brookland, and beyond: uneven temperatures floor to floor, utility bills that climb every season, and a steady stream of dust that no amount of cleaning seems to fix.
Our technicians treat the duct system as a whole. We test for leaks, measure airflow, check insulation, and then seal, repair, or replace only what actually needs it. The goal is straightforward: keep the air you're already paying for inside the ducts and delivered to the rooms where you live.
Common Ductwork Repair & Sealing Problems We Fix
- Hot and cold rooms caused by leaky or unbalanced ducts
- High energy bills from 20-30% of conditioned air leaking out
- Undersized or poorly designed ductwork retrofitted into old row houses
- Uninsulated ducts in attics, basements, and crawlspaces losing heat and cool
- Dusty air and odors drawn in through unsealed return joints
- Disconnected or crushed duct sections reducing airflow
- Weak airflow at registers far from the air handler
What's Included
- Full duct inspection with leak detection to pinpoint where conditioned air is escaping
- Airflow and balance testing to find undersized or restricted runs behind hot-and-cold rooms
- Professional sealing with mastic and UL-rated metal tape, never cloth duct tape that dries out and fails
- Insulating ducts in unconditioned attics, crawlspaces, and basements to stop heat loss and gain
- Repairing disconnected, crushed, or corroded sections and resealing loose joints and boots
- Replacement of duct runs that are too far gone or badly undersized for your home
- A free, no-pressure assessment with upfront flat-rate pricing before any work begins
Washington, DC note: DC's narrow row houses frequently have ductwork squeezed into stair chases, soffits, and converted closets, with runs that were undersized when the home was split into units or finished into living space. We work carefully in these tight, often historic interiors and right-size repairs to the home rather than forcing a one-size-fits-all fix.
Why Choose DC HVAC Repair for Ductwork Repair & Sealing
- Licensed & insured technicians who work on DC homes every day.
- Upfront, flat-rate pricing — approved before any work starts.
- Same-day & 24/7 emergency availability when comfort can't wait.
- 100% satisfaction guarantee on workmanship.
What Does Ductwork Repair & Sealing Cost in DC?
Costs vary with how much of the system needs attention. A targeted sealing of accessible joints and a few problem areas often runs in the range of a few hundred dollars, while sealing plus insulating longer runs in an attic or crawlspace, or replacing damaged sections, typically lands somewhere between roughly $1,000 and $3,000 for a DC home. Larger whole-system replacements run higher. Because every home is different, we start with a free assessment and give you a flat-rate quote up front, so call us for an exact estimate before you commit.
Every job is different — call for a free, no-obligation estimate tailored to your home.