What to expect from LC Heating & Air
### What Duct Sealing Accomplishes Duct sealing is one of the highest-ROI home energy improvements available to Los Angeles homeowners. When conditioned air leaks into attic or wall cavities before reaching the living space, you're paying to condition space you don't occupy. Studies of California homes consistently show 20–30% duct leakage in older homes — and every percentage point of leakage reduction shows up directly in your utility bill.
Overview
### Manual Sealing vs. Aeroseal LC Heating & Air offers two duct sealing approaches. Manual sealing uses mastic (a durable, flexible sealant applied by hand) and foil tape at accessible duct joints, take-offs, supply and return plenums, and connection points. This is the right approach when significant leakage locations are accessible and the duct system is in otherwise good structural condition. Aeroseal internal sealing is our solution for duct systems where significant leakage is distributed throughout the system in locations that aren't manually accessible — it seals from the inside out using a pressurized polymer aerosol that deposits on and seals leak sites as air passes through them.
### California Energy Code and Duct Sealing California Title 24 requires duct sealing testing (duct blaster test) as part of any HVAC replacement permit — and requires that systems failing the test be sealed to meet the leakage standard before permit signoff. If you've replaced HVAC equipment without a permit, or had a permitted replacement that failed to test the ducts, your system may have significant unsealed leakage.
### What You'll Notice After Duct Sealing Homeowners consistently report three immediate improvements after duct sealing: rooms that were previously hard to condition are now comfortable, the HVAC system runs for noticeably shorter cycles to reach the thermostat setpoint, and utility bills decrease. These improvements are permanent — properly applied mastic and Aeroseal are rated for the life of the duct system.
Our Service Benefits
Duct Sealing Cost in Los Angeles
Pricing ranges for common duct sealing services. Your actual cost depends on equipment, complexity, and home configuration. We provide an exact written estimate before any work begins.
Service calls start at $125. Prices include parts and labor unless noted. Financing available on equipment installations. Learn about financing →
What Los Angeles Homeowners Say
“Switched from gas furnace to a heat pump. LC handled the TECH Clean California paperwork — got $2,500 rebate plus federal credit.”
“LC replaced our entire HVAC system. Leo walked us through every option without pressure. The install team was professional and clean.”
“LC found that our ductwork had separated in the attic. Repaired everything and now every room heats equally. Professional and transparent.”
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Signs you need duct sealing
Not sure if you need service? Call us — we'll give you an honest answer.
(323) 970-3113 — Free diagnosisOur duct sealing process
Pre-sealing duct leakage test
We perform a duct blaster test to quantify existing leakage as a percentage of system airflow.
Sealing approach selection
Based on leakage quantity, duct type, and accessibility, we recommend manual sealing, Aeroseal, or a combination.
Duct sealing
We apply mastic to all accessible joints and plenums, or set up and run the Aeroseal process for internal sealing.
Post-sealing verification test
We re-run the duct blaster test and provide you with before/after leakage numbers as written documentation.
300+ verified reviews
Duct Sealing — by city
Common questions about duct sealing in Los Angeles
What customers say about duct sealing
Verified reviews from Los Angeles homeowners who used our duct sealing service.
“LC did a full duct inspection and found we were losing 35% of our conditioned air through disconnected joints in the attic. After sealing and repairing, the difference was immediate — better airflow, lower bills, no more hot spots.”
“Our furnace wasn't heating evenly upstairs. LC found that half of our ductwork in the attic had separated and was blowing hot air into the attic. Repaired everything and now every room heats equally. Professional and transparent.”
“Had LC install a Daikin mini split in our 1940s bungalow that never had AC. The work was clean, the unit is incredibly quiet, and our bedroom finally stays cool in summer. Highly recommend.”
