Professional duct sealing services to stop energy loss and improve home comfort. We use manual mastic sealing and Aeroseal technology to ensure your system performs as intended.
I'm Leo, owner of LC Heating & Air. If you live in the Hollywood Hills West area, you know that our homes—whether they're tucked into a canyon or perched on a hillside—have unique challenges. Often, the biggest drain on your comfort and your energy bill isn't the furnace or the AC unit itself, but the ductwork that carries the air. If your ducts are leaking, you are paying to heat or cool your attic, wall cavities, or crawl spaces instead of your living room.
Duct sealing is one of the most practical, high-return improvements you can make. When we seal your ducts, we aren't just patching holes; we are ensuring that the air your system works hard to condition actually reaches the rooms where you spend your time. We provide honest, licensed service to help you decide if your system needs a simple patch-up or a more comprehensive sealing process.
Local HVAC considerations
Hollywood Hills West (90046)
CSLB #1073586
Duct leakage testing and sealing
Why Hollywood Hills West Homes Need Duct Attention
In our hillside and canyon neighborhoods, the layout of your home often dictates the layout of your ductwork. We frequently see long, complex duct runs that snake through tight mechanical areas or unconditioned attics. Because of the way these homes are built, ducts are often subjected to extreme temperature swings, which causes joints to pull apart and flex duct to degrade over time. When those connections fail, you lose conditioned air directly into the structure.
Another common pattern here is uneven temperature. If you find that one bedroom is always freezing while the living room stays warm, it is rarely just a thermostat issue. It is usually a result of duct leakage or poor airflow distribution. By testing your system, we can identify exactly where that air is escaping and determine if manual mastic sealing or internal Aeroseal is the right fix for your specific home layout.
Working with Hillside Architecture
Hollywood Hills West has a mix of older custom homes and hillside properties that present unique access challenges. When I inspect a system, I am looking at how the equipment is placed and how the line-sets and ducts are routed through the home. In tight-access mechanical areas, standard repairs can be difficult, which is why we offer both manual mastic sealing and the Aeroseal process.
If your home has original sheet metal or older flex duct, it is likely that the connections have dried out or shifted. We don't believe in one-size-fits-all solutions. We look at the physical condition of your ducts first to see if they are structurally sound enough to seal or if they have reached the end of their life.
Our Diagnostic Process
We don't guess. Before we touch anything, we perform a duct blaster test. This is a standard procedure that quantifies exactly how much air is leaking from your system. It gives us a baseline number so we can show you, in writing, how much of your system's capacity is being wasted.
After the test, we walk you through the results. If the leakage is concentrated in accessible areas like the plenum or main trunk lines, we can often handle that with manual mastic sealing. If the leaks are distributed throughout the system in inaccessible wall cavities or floor joists, we will discuss the Aeroseal option. You get the data before you make a decision.
Repair vs. Replacement: Making the Right Call
A common question I get is whether it is worth sealing old ducts or if they should just be replaced. If your ductwork is physically intact but just leaking at the joints, sealing is a permanent, cost-effective solution. Mastic and Aeroseal are rated for the life of the system.
However, if the ducts are crushed, collapsed, or heavily contaminated with mold or debris, sealing them won't solve the underlying problem. In those cases, I will be honest with you that replacement is the better path. We are here to provide a long-term solution, not a temporary patch that will need to be revisited in a year.
Understanding the Costs
Duct sealing costs vary based on the size of your home and the accessibility of the ducts. Manual mastic sealing typically ranges from $400 to $1,200, while the Aeroseal process for a typical single-story home ranges from $1,500 to $3,000. These prices include the necessary duct blaster testing to verify the work.
Because sealing 20–30% of duct leakage can reduce your HVAC energy use by 15–25%, many homeowners find that the system pays for itself in energy savings within a few years. We provide a written estimate after our initial diagnostic so you know exactly what you are paying for before we start.
Scheduling Service in the Hills
We understand that access in the Hollywood Hills can be tricky. Whether it is narrow roads or difficult ladder access, we plan our service calls with these constraints in mind. We aim to complete most residential duct sealing projects in a single day to minimize the disruption to your home.
If you are planning an HVAC replacement, we can coordinate the duct sealing as part of that project to ensure you meet California Title 24 requirements. Give us a call at (323) 970-3113 to discuss your home's specific access needs.
Common Mistakes to Avoid
The biggest mistake I see is the use of standard silver 'duct tape' on HVAC systems. It dries out, loses its adhesive, and fails within a few years. We only use professional-grade mastic and foil-backed HVAC tape. Mastic stays flexible and creates a permanent seal at the joints.
Another mistake is ignoring the return side of the system. Many homeowners focus only on the supply vents, but if your return ducts are leaking, your system is pulling in hot, dusty air from your attic or crawl space. A proper seal must address both the supply and return sides to be effective.
Health and Safety Considerations
Your indoor air quality is our priority. The Aeroseal material we use is non-toxic—it is the same type of polymer used in chewing gum. We recommend that you vacate the home for about 60 to 90 minutes during the injection process as a precaution, but you can return as soon as the system has run to clear the air.
We also ensure that all our work complies with California safety standards. By sealing your ducts, we prevent the system from pulling in insulation fibers, dust, or combustion gases from the attic, which significantly improves the quality of the air circulating through your home.
Is Duct Sealing Right for You?
If you are noticing high utility bills, uneven temperatures, or excessive dust, it is time to look at your ducts. If your system is otherwise functioning well, duct sealing is often the most effective way to improve comfort without the expense of a full equipment replacement.
If you are already planning to replace your furnace or AC, sealing the ducts is a smart move to ensure your new, high-efficiency equipment isn't losing its output to leaky, uninsulated pathways. We are happy to inspect your system and give you an honest assessment of whether sealing will solve your comfort issues.
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 Hollywood Hills West
Reviewed by Leo, Owner & Lead Technician
This duct sealing guide for Hollywood Hills West 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 Hollywood Hills West customers say about duct sealing
Verified reviews from homeowners in Hollywood Hills West 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.”
