### 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
Immediate energy savings
Sealing 20–30% duct leakage typically reduces HVAC energy use by 15–25%. At LA electricity rates, payback is often under 2 years.
Both methods available
Manual mastic sealing for accessible leaks, Aeroseal internal sealing for inaccessible distributed leakage — we use the right approach for each system.
CA Title 24 compliance
We perform duct blaster testing before and after sealing and provide documentation for permit compliance.
Permanent solution
Properly applied mastic and Aeroseal are rated for the life of the duct system — not a temporary fix that degrades over time.
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.
Duct inspection
$125–$200
Duct cleaning (whole house)
$400–$900
Duct sealing
$1,000–$3,000
Duct repair or replacement
$500–$5,000
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.”
M
Michael D.Eagle Rock, CA
“LC replaced our entire HVAC system. Leo walked us through every option without pressure. The install team was professional and clean.”
D
David K.Pasadena, CA
“LC found that our ductwork had separated in the attic. Repaired everything and now every room heats equally. Professional and transparent.”
We perform a duct blaster test to quantify existing leakage as a percentage of system airflow.
02
Sealing approach selection
Based on leakage quantity, duct type, and accessibility, we recommend manual sealing, Aeroseal, or a combination.
03
Duct sealing
We apply mastic to all accessible joints and plenums, or set up and run the Aeroseal process for internal sealing.
04
Post-sealing verification test
We re-run the duct blaster test and provide you with before/after leakage numbers as written documentation.
Customer Reviews
300+ verified reviews
5.0
Google Reviews196 reviews on Google
SM
Sharon Meoded
Los Angeles, CA
“Lior and his team installed an AC unit in my room that doesn’t have central AC and it works amazing! They were so professional and cleaned up fully after themselves. He kept me in the loop the entire process and when he came out prior to installing showed me step by step what they would be doing! Highly recommend ! Super professional”
Google Review
PW
Patricia Williams
Los Angeles, CA
“LC Heating and Air is a reliable, affordable solution for all your central air and heating needs. I am an out of town landlord and it can be difficult to find the assistance I need. LC Heating and Air took care of my tenants issues quickly and explained all issues before making necessary repairs. I will def use them again if need be!”
Google Review
NE
Naomi Eagleson
Los Angeles, CA
“I hired LC Heating & AC to replace the drain pumps in our Mitsubishi Mini Splits and clean the condenser and was pleased with the service. Leo was responsive, thorough, and professional. I chose this company based on the glowing reviews I read online and wasn't disappointed. My husband and I look forward to using our AC this summer!”
Google Review
OI
Osher Itzhaki
Los Angeles, CA
“Amazing service!! I called LC heating and air and was fortunate enough to have scheduled them for a same day appointment . Leo arrived on time and was super friendly, polite and fixed my ax in no time . The price was fair and he explained what further steps I shouted take to keep my ac unit running for more years Thank you LC!!!”
Google Review
JS
Justin Shapiro
West Hollywood, CA
“Great experience!!’ Leo came to my house in West Hollywood at 9pm !! I had an emergency, my ac stopped working out of no where i called LC heating and air from the phone call with the office to the time the tech came the service was just amazing. Leo came and had my ac running in no time. Thank you so much !! Highly recommended”
Google Review
GH
Greg Haroutunian
Los Angeles, CA
“Sunday morning discovered AC in the unit is not working, called everywhere, no one wanted to come the same day. LC Heating came the same day, fixed the problem which apparently wasn't easy to figure out. Very professional, calm and confident, pleasant to work with. Leo was the lead guy. Great experience, highly recommend it!”
Google Review
AV
Adam Valdies
Los Angeles, CA
“Leo and his team were amazing! I am so glad we called them to handle our AC/Heating issue. The problem was not clear at first and required substantial troubleshooting but Leo was extremely communicative and very professional throughout! He figured out the problem and we cannot thank him enough! Highly recommend!”
Google Review
LO
Leeyam Ohayon
Los Angeles, CA
“I called LC Heating & Air when my heating unit stopped working. He came quickly and fixed the problem fast. The technician was very kind and experienced. He explained the problem to me and gave me maintenance tips for the future. I definitely recommend LC Heating and Air if you're in need of these services.”
Google Review
AY
ariel. yona.
Los Angeles, CA
“Amazingly service me heater broke down and I was looking for a local company in my neighborhood. I found LC heating and air I can’t express in words how pleased I was with this company the owner Leo came out was very professional friendly and fixed my heater in no time !!! Highly recommended”
Google Review
KB
kevin benoit
Los Angeles, CA
“I cannot recommend this company more. They came, assess my issue and then ordered the right parts from the company and made an amazing install and transform my AC unit into a smart controlled AC unit which no Other HVAC company was able to do, or wanted to take the time that it took to do it”
Google Review
TY
Todd Yasuda
Los Angeles, CA
“Asher (LC Heating & Air) is the best, he kept me informed throughout the whole process. Everything he told me is exactly how things were done. I couldn’t have asked for a better person to work with. If you want to work with a reliable person and company, I would highly recommend him.”
Google Review
CK
claudia kleinschmidt
Los Angeles, CA
“Our AC was broken and had been dripping for a couple days. Once we called LC heating and air they sent out Asher to fix it immediately. He checked out the AC and fixed the problem on the spot. He was super professional and informative. Highly recommend Asher and the company!”
Google Review
DF
D Fan
Los Angeles, CA
“Leo is the absolute best! Had an emergency call and he came out right away in the early evening. Showed me how my units work and what the problem was. A few minutes later, it was fixed and working again! I cannot recommend this guy more highly. Call him and you'll be happy!”
Google Review
JM
Jamie Morgan
Los Angeles, CA
“LC Heating and AC is the best! I couldn’t recommend enough. It was a 100/10 experience. Helped me get to the bottom of repairing my AC that was very complicated and messed up by someone else. They are very professional and kind on top be being super knowledgeable.”
Google Review
DA
dan amiel
Los Angeles, CA
“Great service my heater stopped working out of the blue and we just had a new born I called lc heating and air they were the only ones that answered they came out and a hour my heater was up and running I couldn’t thank them enough . Highly recommended”
Google Review
YG
Yane G.
Los Angeles, CA
“Very helpful and very respectful. I called for a repair and was answered immediately, they were great in explaining what was going wrong and how they would fix it i was glad with there work and would definitely be calling them for any future repairs.”
Google Review
LA
Leetal Adelle Cohen
Los Angeles, CA
“We reached out to Leo and had a new HVAC system installed by him and his crew. Very happy with the results! Very professional, knowledgeable and patient. The whole process was very smooth, quick and clean. System works perfectly. Highly recommend”
Google Review
AM
Agam Mashiah
Los Angeles, CA
“I called lc heating to fix my heater in my house . We decided to replace the heater throughout the whole out process the customer service was great they were very communicative, professional and were very clean . Thank you again for the great job”
Google Review
CR
Charles Raffini
Los Angeles, CA
“HVAC system was leaking in the attic. Leo took my call late at night and came immediately. He stopped the leak and came back to make sure the system was working properly. Very responsive, good work and great value. Highly recommend them.”
Google Review
YY
yoav yerushalmi
Los Angeles, CA
“Scheduled an appointment very quickly for our HVAC unit that was having trouble cooling. Were very meticulous and clean. Helped idenitfy the issue and did a great job explaining what needs to be done and doing it. Highly recommended...”
Google Review
SM
Sharon Meoded
Los Angeles, CA
“Lior and his team installed an AC unit in my room that doesn’t have central AC and it works amazing! They were so professional and cleaned up fully after themselves. He kept me in the loop the entire process and when he came out prior to installing showed me step by step what they would be doing! Highly recommend ! Super professional”
Google Review
PW
Patricia Williams
Los Angeles, CA
“LC Heating and Air is a reliable, affordable solution for all your central air and heating needs. I am an out of town landlord and it can be difficult to find the assistance I need. LC Heating and Air took care of my tenants issues quickly and explained all issues before making necessary repairs. I will def use them again if need be!”
Google Review
NE
Naomi Eagleson
Los Angeles, CA
“I hired LC Heating & AC to replace the drain pumps in our Mitsubishi Mini Splits and clean the condenser and was pleased with the service. Leo was responsive, thorough, and professional. I chose this company based on the glowing reviews I read online and wasn't disappointed. My husband and I look forward to using our AC this summer!”
Google Review
OI
Osher Itzhaki
Los Angeles, CA
“Amazing service!! I called LC heating and air and was fortunate enough to have scheduled them for a same day appointment . Leo arrived on time and was super friendly, polite and fixed my ax in no time . The price was fair and he explained what further steps I shouted take to keep my ac unit running for more years Thank you LC!!!”
Google Review
JS
Justin Shapiro
West Hollywood, CA
“Great experience!!’ Leo came to my house in West Hollywood at 9pm !! I had an emergency, my ac stopped working out of no where i called LC heating and air from the phone call with the office to the time the tech came the service was just amazing. Leo came and had my ac running in no time. Thank you so much !! Highly recommended”
Google Review
GH
Greg Haroutunian
Los Angeles, CA
“Sunday morning discovered AC in the unit is not working, called everywhere, no one wanted to come the same day. LC Heating came the same day, fixed the problem which apparently wasn't easy to figure out. Very professional, calm and confident, pleasant to work with. Leo was the lead guy. Great experience, highly recommend it!”
Google Review
AV
Adam Valdies
Los Angeles, CA
“Leo and his team were amazing! I am so glad we called them to handle our AC/Heating issue. The problem was not clear at first and required substantial troubleshooting but Leo was extremely communicative and very professional throughout! He figured out the problem and we cannot thank him enough! Highly recommend!”
Google Review
LO
Leeyam Ohayon
Los Angeles, CA
“I called LC Heating & Air when my heating unit stopped working. He came quickly and fixed the problem fast. The technician was very kind and experienced. He explained the problem to me and gave me maintenance tips for the future. I definitely recommend LC Heating and Air if you're in need of these services.”
Google Review
AY
ariel. yona.
Los Angeles, CA
“Amazingly service me heater broke down and I was looking for a local company in my neighborhood. I found LC heating and air I can’t express in words how pleased I was with this company the owner Leo came out was very professional friendly and fixed my heater in no time !!! Highly recommended”
Google Review
KB
kevin benoit
Los Angeles, CA
“I cannot recommend this company more. They came, assess my issue and then ordered the right parts from the company and made an amazing install and transform my AC unit into a smart controlled AC unit which no Other HVAC company was able to do, or wanted to take the time that it took to do it”
Google Review
TY
Todd Yasuda
Los Angeles, CA
“Asher (LC Heating & Air) is the best, he kept me informed throughout the whole process. Everything he told me is exactly how things were done. I couldn’t have asked for a better person to work with. If you want to work with a reliable person and company, I would highly recommend him.”
Google Review
CK
claudia kleinschmidt
Los Angeles, CA
“Our AC was broken and had been dripping for a couple days. Once we called LC heating and air they sent out Asher to fix it immediately. He checked out the AC and fixed the problem on the spot. He was super professional and informative. Highly recommend Asher and the company!”
Google Review
DF
D Fan
Los Angeles, CA
“Leo is the absolute best! Had an emergency call and he came out right away in the early evening. Showed me how my units work and what the problem was. A few minutes later, it was fixed and working again! I cannot recommend this guy more highly. Call him and you'll be happy!”
Google Review
JM
Jamie Morgan
Los Angeles, CA
“LC Heating and AC is the best! I couldn’t recommend enough. It was a 100/10 experience. Helped me get to the bottom of repairing my AC that was very complicated and messed up by someone else. They are very professional and kind on top be being super knowledgeable.”
Google Review
DA
dan amiel
Los Angeles, CA
“Great service my heater stopped working out of the blue and we just had a new born I called lc heating and air they were the only ones that answered they came out and a hour my heater was up and running I couldn’t thank them enough . Highly recommended”
Google Review
YG
Yane G.
Los Angeles, CA
“Very helpful and very respectful. I called for a repair and was answered immediately, they were great in explaining what was going wrong and how they would fix it i was glad with there work and would definitely be calling them for any future repairs.”
Google Review
LA
Leetal Adelle Cohen
Los Angeles, CA
“We reached out to Leo and had a new HVAC system installed by him and his crew. Very happy with the results! Very professional, knowledgeable and patient. The whole process was very smooth, quick and clean. System works perfectly. Highly recommend”
Google Review
AM
Agam Mashiah
Los Angeles, CA
“I called lc heating to fix my heater in my house . We decided to replace the heater throughout the whole out process the customer service was great they were very communicative, professional and were very clean . Thank you again for the great job”
Google Review
CR
Charles Raffini
Los Angeles, CA
“HVAC system was leaking in the attic. Leo took my call late at night and came immediately. He stopped the leak and came back to make sure the system was working properly. Very responsive, good work and great value. Highly recommend them.”
Google Review
YY
yoav yerushalmi
Los Angeles, CA
“Scheduled an appointment very quickly for our HVAC unit that was having trouble cooling. Were very meticulous and clean. Helped idenitfy the issue and did a great job explaining what needs to be done and doing it. Highly recommended...”
Common questions about duct sealing in Los Angeles
How much energy can duct sealing save?
Studies of California homes find average savings of 15–25% of HVAC energy use after professional duct sealing. The actual savings depend on your pre-sealing leakage rate — a home with 30% leakage can save significantly more than a home with 10% leakage. We quantify your specific leakage before sealing so you can estimate your expected savings.
What is the difference between mastic and duct tape for sealing ducts?
Standard "duct tape" (the silver cloth tape) is not suitable for HVAC ductwork — it dries out and fails within a few years. Mastic is a thick, flexible sealant applied with a brush or by hand that remains pliable and adheres permanently. Foil-backed HVAC tape (not cloth duct tape) is also suitable for certain applications. We use mastic on joints, plenums, and connections where it will provide a long-term seal.
How does Aeroseal work?
Aeroseal pressurizes your duct system and injects a fine mist of vinyl acetate polymer particles. As air escapes through leaks, the particles accumulate on the edges of the leak openings and progressively seal them — the same mechanism that causes a cut to heal. Leaks up to 5/8" can be sealed. A computer monitors leakage reduction in real time and stops when the target is reached.
Is Aeroseal safe?
Yes. The vinyl acetate polymer used in Aeroseal is the same material used in chewing gum and many food products. It's non-toxic and has been tested for indoor air quality impacts. The Aeroseal process includes a testing phase that confirms the interior of your ducts is clean before sealing, and the sealant remains in the duct walls, not in the airstream after curing.
How much does duct sealing cost in Los Angeles?
Manual mastic sealing of accessible duct sections: $400–$1,200 depending on system size and accessibility. Aeroseal internal sealing: $1,500–$3,000 for a typical single-story home. Both include before/after duct blaster testing. We provide a written estimate after the pre-sealing diagnostic.
Does duct sealing require permits in California?
Standalone duct sealing as a maintenance activity generally doesn't require a permit. When duct sealing is performed as part of an HVAC replacement project, the replacement permit typically requires duct leakage testing and documentation. We advise on applicable requirements for your specific project.
How long does duct sealing take?
Manual sealing of a typical single-family home duct system: 4–8 hours. Aeroseal process: 4–6 hours for the sealing itself plus setup and testing time. We complete most residential duct sealing projects in a single day.
Do I need to leave my home during Aeroseal?
We recommend vacating the home during the Aeroseal injection process (approximately 60–90 minutes) as a precaution, though the material is non-toxic. You can return as soon as the process is complete and the system has run briefly to clear any residual particles from the airstream.
Verified Reviews
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.”
L
Linda F.
Northridge, CA · Sep 2025
“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.”
S
Sarah T.
Studio City, CA · Nov 2025
“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.”