LC Heating & Air provides expert duct sealing services to help Norwalk homeowners stop energy loss, improve indoor comfort, and ensure their HVAC systems perform as designed.
Duct Cleaning & Air Duct Service in Norwalk
LC Heating & Air provides duct cleaning in Norwalk — including air duct cleaning, duct repair service, duct sealing, HVAC ductwork. Whether you need same-day service, a written estimate, or help deciding between repair and replacement, our licensed technicians handle every make and model.
We repair and service all major HVAC brands in Norwalk, including Carrier, Trane, and Goodman, and older or discontinued units. No matter the manufacturer, we diagnose the problem accurately and give you an upfront price before any work begins.
I'm Leo, owner of LC Heating & Air. I spend a lot of time in Norwalk homes, and I see the same issue over and over: homeowners are paying to heat or cool their attic, crawl space, or wall cavities instead of their living rooms. Duct leakage is one of the most common reasons an HVAC system struggles to keep up, even when the equipment itself is in good shape.
My approach is simple: we don't guess. We use duct blaster testing to measure exactly how much air you are losing. Whether your home needs manual mastic sealing or our Aeroseal process, we provide a clear, written estimate so you know exactly what you are paying for and what kind of improvement you can expect.
Call LC Heating & Air at (323) 970-3113 for scheduling and estimates.
Local HVAC considerations
Why Duct Sealing Matters in Norwalk
In Norwalk, our climate means your HVAC system works hard. When your ducts leak, that conditioned air escapes into unconditioned spaces like attics or garages. This forces your furnace or air conditioner to run longer cycles just to maintain the temperature you set on the thermostat. It’s a waste of energy and money.
We often see older homes in this area with original sheet metal or aging flex ductwork that has simply degraded over time. If you notice dust building up around your registers or if one room in your house is always hotter or colder than the rest, it’s a strong sign that your duct system is leaking.
Understanding Your Home's Ductwork
Norwalk has a mix of single-family homes, duplexes, and small multifamily buildings. Many of these properties have undergone remodels over the years, which can sometimes lead to ductwork that was never properly balanced or sealed during the renovation process.
Before we recommend any work, we look at the whole picture: your duct condition, airflow, and equipment placement. If you are planning an HVAC replacement, it is the perfect time to address the ducts. California Title 24 requires duct leakage testing for permitted replacements, and we ensure your system meets those standards.
Our Diagnostic Process
We don't just look at the ducts and guess. We perform a duct blaster test to quantify your leakage as a percentage of total airflow. This gives us a baseline number so you can see exactly how much air your system is losing.
Once we have the data, we decide on the best approach. If the leaks are in accessible joints and plenums, we use mastic—a durable, flexible sealant that stays pliable for the life of the system. If the leaks are distributed throughout inaccessible areas, we use the Aeroseal process to seal them from the inside out.
Repair vs. Replacement Decisions
A common question I get is whether to repair old ducts or replace them entirely. If the ductwork is structurally sound but just leaky at the joints, sealing is almost always the right move. It’s cost-effective and provides immediate energy savings.
However, if the ducts are crushed, heavily contaminated, or undersized for your equipment, sealing won't fix the underlying airflow problem. In those cases, I will tell you straight that replacement is the better long-term investment. We want to make sure the fix fits your home, not just sell you a service.
What to Expect Regarding Costs
We believe in transparency. A duct inspection typically runs between $125 and $200. If you need manual mastic sealing, you are looking at $400 to $1,200, while Aeroseal internal sealing for a typical single-story home ranges from $1,500 to $3,000.
These costs include the before-and-after testing required to verify the work. When you consider that sealing 20–30% duct leakage can reduce your HVAC energy use by 15–25%, the payback period is often short. We provide a written estimate after our diagnostic so there are no surprises.
Scheduling Your Service
We know your time is valuable. Most residential duct sealing projects in Norwalk can be completed in a single day. Whether we are manually sealing joints in your attic or running the Aeroseal process, we work efficiently to minimize the disruption to your home.
If you are interested in a consultation, give us a call at (323) 970-3113. We will discuss your specific situation and schedule a time to come out, inspect your system, and provide a professional recommendation.
Common Duct Sealing Mistakes
The biggest mistake I see is the use of standard 'duct tape'—the silver cloth stuff you buy at the hardware store. It dries out, cracks, and falls off within a few years. It is not rated for HVAC systems. We only use professional-grade mastic and foil-backed HVAC tape that is designed to stay sealed for the life of your ductwork.
Another mistake is skipping the testing. Without a duct blaster test, you have no way of knowing if the sealing actually worked or if you just paid for someone to put tape on a few visible joints while the real leaks remained hidden.
Health and Safety Considerations
We take safety seriously. The Aeroseal process uses a non-toxic vinyl acetate polymer—the same material used in chewing gum—and it is perfectly safe for your home. We do recommend that you step out for about 60 to 90 minutes while we run the injection process, but you can return as soon as we are finished.
Our process also includes a verification phase to ensure the interior of your ducts is clean and that the sealant is contained where it belongs. We are fully licensed (CSLB #1073586) and insured, so you can have peace of mind knowing the work is being done by a professional.
Is Duct Sealing Right for Your Home?
If your HVAC system is running constantly but your home still feels uneven, or if your energy bills seem high for the size of your house, duct sealing is a high-value improvement. It’s a permanent fix that stops the waste of conditioned air.
If you are ready to stop guessing, give LC Heating & Air a call. We will come out, inspect your system, and give you an honest assessment of whether sealing will solve your comfort issues or if there is a larger problem that needs to be addressed.
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 system size and complexity
- • Accessibility of ductwork in attics or crawl spaces
- • Total percentage of leakage found during diagnostic testing
- • Choice between manual mastic sealing and Aeroseal internal sealing
Useful next steps
Duct Sealing in Norwalk at a glance
- • Duct Sealing provider: LC Heating & Air
- • Location served: Norwalk, CA 90650
- • License: CSLB C-20 #1073586
- • Phone: (323) 970-3113
- • Estimate: written estimate before approved work
- • Emergency calls answered within 30 minutes (24/7)
Our duct sealing process in Norwalk
Reviewed by Leo, Owner & Lead Technician
This duct sealing guide for Norwalk 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 Norwalk customers say about duct sealing
Verified reviews from homeowners in Norwalk and nearby neighborhoods who used our duct sealing service.
“AC wasn't cooling to setpoint even though it was running all day. LC found the condenser coils were completely clogged with cottonwood. Cleaned them on the spot and the system cooled my house 12 degrees in an hour.”
“LC replaced our entire HVAC system — new Carrier condenser, furnace, and coil. Leo walked us through every option without pressure. The install team was professional and clean. System runs perfectly and our electricity bill dropped about 30%.”
“Called LC because our CO detector went off. Their technician found a crack in the heat exchanger and immediately shut down the furnace. He explained the safety issue clearly, provided a replacement estimate, and didn't try to scare us — just facts.”
