Why it matters to you
Many Charleston homes run ducts through 130-degree attics and humid crawlspaces, so leaky supply ducts waste cooling and leaky returns pull hot, damp, dusty air straight into the system. Sealing is one of the quieter wins for comfort, humidity, and indoor air quality in a Lowcountry home.
Practical guidance
Watch for rooms that never cool, weak airflow at distant registers, dusty air, or bills out of proportion to equipment age. Ask for a measured duct leakage test before and after any sealing work so you can see the improvement — and so the job documents what utility rebate programs require.
How do I know if my ducts are leaking?
Common signs are rooms that never reach the thermostat setting, weak airflow at the farthest registers, excess dust, a humid or musty house, and cooling bills that seem high for the equipment's age. Visible gaps or disconnected runs in the attic or crawlspace are a clue, but only a duct leakage test actually measures how much air is lost.
What does professional duct sealing involve?
A technician locates leaks at joints, boots, plenums, and connections, then seals them with mastic or approved foil tape, or with an aerosol sealant injected from inside the ducts. Ordinary cloth duct tape fails over time and is not a proper seal. Crushed, torn, or disconnected sections are repaired, and insulation is restored where it was disturbed.
Is there a rebate for duct sealing in the Charleston area?
Dominion Energy South Carolina lists a rebate for duct sealing or duct insulation in existing homes for its residential electric customers. The work must be done by a licensed contractor with before-and-after duct leakage testing, and the application with a detailed invoice must be submitted within the program's deadline after installation. Confirm current amounts and terms on Dominion's site before the work starts.
Is sealing enough, or do my ducts need replacing?
Localized leaks in otherwise sound ducts seal well. Systemic leakage, crushed runs, deteriorated duct board, pest damage, or ducts that were undersized from the start usually argue for replacement, which is also the chance to fix returns and run sizing.
