LC Heating & Air provides expert duct sealing services to help East Hollywood homeowners stop energy loss, improve indoor comfort, and lower utility bills. We use professional duct blaster testing to identify leaks and apply permanent sealing solutions.
If your HVAC system is running constantly but your rooms still feel uneven, the problem might not be the unit itself—it could be your ductwork. In East Hollywood, we see many homes where conditioned air is leaking into attics, wall cavities, or crawl spaces before it ever reaches your living room. You are paying to cool or heat spaces you don't even occupy.
At LC Heating & Air, I believe in fixing the root cause. Whether your home is an older single-family house or a newer remodel, we use diagnostic testing to find exactly where your system is losing air. We don't just guess; we measure, seal, and verify the results so you know exactly what you are paying for.
Local HVAC considerations
East Hollywood (90027)
CSLB #1073586
(323) 970-3113
Why Duct Sealing Matters in East Hollywood
East Hollywood has a mix of older single-family homes and small multifamily buildings. Many of these properties have duct systems that have never been inspected or sealed properly. When ducts leak, your HVAC system has to work much harder to maintain the temperature you set on your thermostat.
In our climate, heat gain in attics is a major issue. If your ducts are leaking in a hot attic, you are essentially pumping hot, dusty air into your home while your expensive cold air escapes outside. This leads to higher energy bills and premature wear on your HVAC equipment.
Understanding Your Home's Ductwork
The age and construction of your home dictate how we approach your ductwork. In many local remodels, we find flex ducts that have been crushed or poorly routed during construction, which restricts airflow. In older homes, sheet metal joints often have gaps that were never sealed during the original installation.
Before we recommend any repair, we look at the whole system. We check for return sizing issues, insulation quality, and register balance. If your ducts are in poor structural condition, sealing might not be enough, and we will be honest with you about whether a partial or full replacement is the more practical long-term investment.
Our Diagnostic Process
We don't start sealing until we know exactly where the leaks are. We start with a duct blaster test, which quantifies your existing leakage as a percentage of total system airflow. This gives us a baseline to measure our success.
Once we have the data, we decide on the best approach. If the leaks are at accessible joints and plenums, we use mastic—a durable, flexible sealant that stays pliable for the life of the duct. If the leaks are distributed throughout the system in inaccessible areas, we use the Aeroseal process to seal them from the inside out.
Repair vs. Replace: Making the Right Call
A common question I get is whether to patch up old ducts or replace them entirely. If your ductwork is structurally sound but just has leaky joints, sealing is almost always the right move. It’s cost-effective and provides immediate results.
However, if the ducts are severely damaged, undersized for your equipment, or heavily contaminated with dust and debris, sealing is just a band-aid. In those cases, I will tell you that replacement is the better path. My goal is to provide a solution that lasts, not one that requires a callback in six months.
What to Expect Regarding Costs
Duct sealing costs vary based on the size of your home and the complexity of the duct layout. Manual mastic sealing typically ranges from $400 to $1,200, while Aeroseal internal sealing for a typical single-story home ranges from $1,500 to $3,000. These prices include the diagnostic testing required to verify the work.
While it is an investment, keep in mind that sealing 20–30% duct leakage can reduce your HVAC energy use by 15–25%. At current LA electricity rates, many homeowners find the payback period is under two years.
Scheduling and Access
We respect your time and your home. Before we start, we check for electrical access, duct condition, and equipment placement to ensure we can complete the job efficiently. Most residential duct sealing projects in East Hollywood are completed in a single day.
If we are performing Aeroseal, we do recommend that you vacate the home for about 60–90 minutes during the injection process. It is a non-toxic, safe procedure, but it’s best to let the system clear out before you return. We will coordinate this with you during the scheduling process.
Common Mistakes We See
The biggest mistake I see is the use of standard silver 'duct tape' on HVAC joints. It dries out, cracks, and falls off within a few years. We use professional-grade mastic that stays flexible. Another mistake is assuming that all duct cleaning is the same as duct sealing—cleaning removes dust, but it doesn't stop the air leaks that are actually costing you money.
Also, many homeowners replace their HVAC unit but skip the duct testing. If your new, efficient unit is connected to leaky, inefficient ducts, you aren't getting the performance you paid for. California Title 24 actually requires duct leakage testing for permitted replacements for this exact reason.
Health and Safety
Your indoor air quality is a priority. Leaky ducts don't just lose conditioned air; they can pull in dust, insulation fibers, and pollutants from your attic or crawl space. By sealing these leaks, we prevent those contaminants from being circulated throughout your home.
We are fully licensed and insured (CSLB #1073586). We follow all safety protocols to ensure that our work complies with local codes and that your home remains a safe, healthy environment for your family.
Is Duct Sealing Right for You?
If your energy bills are high, your rooms have uneven temperatures, or you notice dust buildup near your registers, it is time for an inspection. We will come out, perform a duct blaster test, and give you a written estimate.
If the system is worth repairing, we will tell you. If the pattern points to replacement, we will explain why. We are here to help you make an informed decision based on the reality of your home's specific needs.
How the visit works
We perform a duct blaster test to quantify existing leakage as a percentage of system airflow.
Based on leakage quantity, duct type, and accessibility, we recommend manual sealing, Aeroseal, or a combination.
We apply mastic to all accessible joints and plenums, or set up and run the Aeroseal process for internal sealing.
We re-run the duct blaster test and provide you with before/after leakage numbers as written documentation.
Cost factors we review before quoting
- • Duct inspection: $125–$200
- • Duct cleaning (whole house): $400–$900
- • Duct sealing: $1,000–$3,000
- • Duct repair or replacement: $500–$5,000
Useful next steps
Our duct sealing process in East Hollywood
Reviewed by Leo, Owner & Lead Technician
This duct sealing guide for East Hollywood is reviewed for practical HVAC accuracy by Leo at LC Heating & Air. LC Heating & Air holds California CSLB C-20 HVAC license #1073586 and provides written estimates before approved work.
What East Hollywood customers say about duct sealing
Verified reviews from homeowners in East Hollywood and nearby neighborhoods who used our duct sealing service.
“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.”
“We converted our garage into an ADU and needed HVAC. LC installed a Mitsubishi single-zone mini split — permits, electrical, everything. The unit is so quiet you can barely hear it running. Our tenant loves it.”
“Got a 3-zone Daikin system for our craftsman home — bedrooms upstairs, living room downstairs. Each room has its own temperature control and the monthly electric bill is actually lower than our old window units combined.”
