Whole-system duct and dryer vent check with before-and-after photos - you see exactly what came out of your vents
That "$99 whole-house special" is a bait ad - the real number appears once they are in your hallway, or the "clean" is a shop-vac at the register. We photograph the inside of your ducts before and after instead.
Fast, Reliable Duct Sealing Across Montclair
Duct sealing in Montclair typically runs $800 – $2,400 for a whole-home system, with most 1950s ranch homes falling in the $1,200 – $1,800 range depending on duct accessibility and leak severity. We dispatch crews from our Inland Empire office to Montclair daily, and we know the difference between sealing ductwork in a post-war tract home off Holt Boulevard versus a newer townhome near the 10 freeway. Our Duct Sealing team has worked on enough original gravity-furnace duct runs in Montclair to know where the leaks hide before we open the first register. Call (361) 326-5060 for a free written estimate.
We’re Hollis Air Duct Cleaning, part of the Garrison Partners family since 2004. Every job gets a written price before we start, background-checked uniformed technicians, and our 365-Day Done Right Promise in writing. If the seal fails within a year, we come back and make it right at no charge, including a free second visit.
Why Hollis Air Duct Cleaning Is Montclair’s Preferred Duct Sealing Company
We’ve sealed ducts in enough Montclair homes to know the local pattern: the original interior duct runs in those 1950s and 1960s ranch houses weren’t built tight, and decades of hot-cold cycling have opened gaps at plenums, joints, and register boots that pull in crawlspace air, attic air, and whatever the Santa Ana winds are carrying that week. Our crews don’t guess where the leaks are. We run a camera first, pressurize the system under negative air with HEPA filtration, and mark every loss point before we seal.
Roy Castellanos built this operation on The Garrison Standard: arrive inside the quoted window, price in writing, complete the job by the book, leave the site clean. That standard travels with our technicians into every Montclair home. No estimates that balloon once we’re inside. No per-vent pricing games. One flat price per system, agreed before we touch anything.
Our phones are answered by a live person 24 hours a day, 7 days a week. No voicemail loops, no callback queues, no waiting until Monday to schedule. When you’re dealing with dust loading from the first Santa Ana wind of the season, you don’t need a callback on Tuesday.
Duct Insulation in Montclair
Duct Insulation in Montclair addresses a specific problem in the city’s older housing stock: unconditioned attic and crawlspace duct runs that bleed heated or cooled air into spaces where it does no good. In a 1958 ranch home with original low-pitched roof lines, the attic space gets brutally hot in July and August, and uninsulated supply ducts can lose 20 – 30% of their thermal energy before the air reaches the register. We see this constantly in the neighborhoods north of Holt Boulevard, where post-WWII construction prioritized speed over efficiency.
Typical duct insulation in Montclair runs $1,100 – $2,800 for a full system, with partial runs (attic-only or crawlspace-only) starting around $600. We use professional-grade materials from Abatement Technologies and Guardsman, not the hardware-store wrap that sags and falls within two seasons.
When Insulation Makes Sense
Insulation pays off when your ducts are already sealed but rooms stay uncomfortable, or when energy bills spike in summer despite the AC running constantly. In Montclair’s climate, we recommend insulation after sealing is complete, never before. Sealing first stops the air loss; insulation then preserves the thermal energy you’ve already paid to create.
Combining With Sealing
Most Montclair homeowners need both. We bundle duct sealing and insulation under a single written price, completed in one visit. The crew arrives with Rotobrush agitation tools, Nikro negative-air machines, and the insulation materials needed to finish the job without a return trip. One flat price, one appointment, one year of coverage under our 365-Day Done Right Promise.
HVAC Duct Sealing in Montclair
HVAC Duct Sealing in Montclair is the core service for homeowners battling dust, uneven temperatures, or rising energy bills in the city’s older neighborhoods. The process starts with a camera inspection of the full duct network, followed by pressure testing to quantify leakage against the total system airflow. We then seal accessible leaks with mastic or mechanical fasteners, depending on the duct material and location, while running negative-air HEPA filtration to capture any debris disturbed during the work.
Whole-system HVAC duct sealing in Montclair typically costs $1,200 – $2,200 for a single-story ranch home with crawlspace and attic runs. Two-story homes or systems with hardboard ductwork (common in 1960s Montclair construction) can run $2,000 – $3,500 due to access challenges.
Camera-First Diagnostics
We don’t seal what we can’t see. Our technicians run a borescope through every accessible duct section, looking for open joints, disconnected boots, and corrosion at the plenum. In Montclair’s 1950s gravity-furnace systems, we often find the original duct runs were never fully sealed at installation, just taped with products that failed decades ago.
Negative-Air Containment
During sealing, we maintain negative pressure in the duct system using Nikro equipment, with HEPA filtration exhausting to the exterior. This prevents dust and sealant fumes from entering living spaces, and it lets us verify seal integrity in real time by monitoring pressure recovery. For homes near open land east of Holt Boulevard, where silica dust and pollen loads are extreme, this containment step is non-negotiable.
Trusted Brands We Service in Montclair
We stock parts and materials from Honeywell, Aprilaire, and Abatement Technologies for Montclair jobs, which means faster turnaround when a sealing job reveals a failed component that needs replacement. Honeywell media air cleaners and Aprilaire whole-house dehumidifiers integrate directly with sealed duct systems to maintain the air quality gains after we’re gone. We don’t sell equipment you don’t need, but when a Montclair homeowner’s 1950s system needs a modern filtration upgrade to handle Santa Ana wind events, we have the components on the truck and the expertise to install them without a second appointment.
Common Duct Sealing Problems We See in Montclair Homes
- Foil tape failures on original 1950s joints. The tape dries and cracks in Montclair’s hot attic spaces, creating leaks that pull attic dust and insulation particles into supply air. We remove failed tape entirely and seal with mastic rated for temperature cycling, applied after camera confirmation of the full leak path.
- Open return ducts in vented crawlspaces. Many Montclair ranch homes have return plenums or duct sections in crawlspaces vented to exterior air. During Santa Ana wind events, these openings pull fine desert dust directly into the system, loading the blower motor and bypassing any interior filter. We seal these returns and recommend sealed crawlspace strategies where practical.
- Disconnected flex duct from later retrofits. Homes that added central AC to original gravity-furnace ductwork often have flex duct connections in attics that have pulled loose over decades of thermal movement. The gap blows conditioned air into the attic and creates negative pressure that pulls dust through every remaining leak in the system.
- Sealing over debris without source removal. Some crews seal ducts without first cleaning them, trapping decades of accumulated dust, pollen, and wildfire ash inside. We clean under negative pressure with HEPA filtration before we seal, so the duct interior matches the seal quality.
Pricing for Duct Sealing in Montclair, CA
Whole-home duct sealing in Montclair runs $800 – $2,400, with most single-story ranch homes in the $1,200 – $1,800 range. Two-story homes, hardboard duct systems, or properties requiring extensive crawlspace work can reach $2,200 – $3,500. Duct insulation adds $600 – $2,800 depending on scope. We do not quote per-vent prices, and we do not bait with a low teaser that jumps once the technician arrives.
What moves the price: accessibility (crawlspace height, attic pitch), duct material (metal, flex, or hardboard), leak severity measured during pressure testing, and whether source removal is needed before sealing. Every Montclair homeowner receives a written, itemized price before we begin. If the scope doesn’t change, the price doesn’t change. Estimates are free. Call (361) 326-5060 to schedule.
We Also Serve Cities Near Montclair
Our crews work across the eastern San Gabriel Valley and western Inland Empire, including Duct Sealing in Montclair and surrounding communities. We regularly service Claremont, Ontario, Pomona, and La Verne with the same written pricing, uniformed technicians, and 365-Day Done Right Promise that Montclair homeowners expect. Dispatch and scheduling are coordinated from our Inland Empire office.
Serving Montclair, CA - Our Local Coverage Area
We’re based in the Montclair area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
FAQs About Duct Sealing in Montclair
Every 8 – 12 years for most rural-edge Montclair properties, sooner if the original seal was tape-only or if the home has a vented crawlspace pulling in silica dust from unpaved roads. The fine dust east of Holt Boulevard stays airborne longer than freeway silt, and it works into seal edges during thermal cycling. We inspect seal integrity with pressure testing at every cleaning interval and touch up before full failure. Call (361) 326-5060 to schedule an inspection.
Yes, significantly, but only when the full leak path is sealed, not just the obvious gaps. In 1950s Montclair ranch homes, Santa Ana wind dust enters through open plenum joints, crawlspace-vented returns, and register boots that have separated from drywall. We ran a duct sealing job on a 1958 ranch home off Holt Boulevard where the original interior duct runs and a gravity furnace had never been opened; the homeowner’s complaint was dust on registers within days of the first Santa Ana wind. Using a Rotobrush with agitation tools and a camera inspection, we found open joints at the plenum pulling dirt straight from a crawlspace vented to open land, and we sealed them under negative pressure with HEPA filtration running. Registers stayed clean through the next wind event, and the blower motor amp draw came down after the leak was closed.
Yes, if you use the space regularly and the ductwork is connected to your main HVAC system or a dedicated unit. Outbuilding ducts in Montclair’s rural-edge areas load with even more dust and pollen than main homes because they’re often on gravel pads with less foundation sealing. We seal these systems with the same mastic and mechanical methods, and we recommend a dedicated filter upgrade (MERV 11 – 13) because outbuilding air handlers run less frequently, allowing debris to settle and recirculate in concentrated bursts.
MERV 11 for standard systems, MERV 13 if the blower motor and coil can handle the static pressure. After sealing, your HVAC system moves air more efficiently, which means the filter actually does its job instead of bypassing through leaks. For Montclair homes east of Holt Boulevard facing open land and unpaved roads, MERV 13 with a sealed system captures the fine silica dust and pollen that loads during Santa Ana events. We verify blower amp draw after sealing to confirm the system can handle the higher filtration load without strain.
Because the wind reveals leaks that were hidden during calmer months. When sustained 40 – 60 mph winds hit, they pressurize attics and crawlspaces, forcing dust through every duct gap and into living spaces. Montclair homeowners who’ve never noticed a problem suddenly see dust on registers within 24 hours. The calls cluster in the older single-story neighborhoods near Holt Boulevard and the 10 freeway, where dust infiltration is worst and many homes still have original gravity furnaces with ductwork that hasn’t been opened in decades. Sealing before wind season prevents the spike; sealing after it fixes the immediate problem and prevents the next one.
Written by Roy Castellanos, Owner at Hollis Air Duct Cleaning, serving Montclair and the Inland Empire since 2004.




Before
After
Before
After
Before
After