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.
Before
After
Before
After
Before
AfterFast, Reliable Duct Sealing Across Universal City
Duct sealing in Universal City typically runs $450 – $1,200 for a whole-home job, depending on whether we’re patching pinholes in original galvanized steel or resealing an entire flex-duct system in newer construction. Most Universal City homeowners see the work completed in a single visit, with written pricing agreed before any mastic goes on. Call (361) 326-5060 for a free estimate.
We’ve been driving out to Universal City from our San Antonio dispatch office since 2004, and we know the difference between a 1968 ranch off Pat Booker Road and a 2005 build near the Loop 1604 corridor. That matters because the duct problems, the sealing methods, and the price ranges are completely different. Our Duct Sealing team carries mastic and mesh for rusted galvanized, replacement flex for crushed runs, and manometers to check static pressure on systems never designed for modern airflow. We don’t guess. We look, we measure, we price it in writing, then we seal it.
Why Hollis Air Duct Cleaning Is Universal City’s Preferred Duct Sealing Company
Universal City homeowners call us back because we show up inside the window, in uniform, and we leave the price where we wrote it down. That’s The Garrison Standard. No other duct company in this market puts a 365-Day Done Right Promise in writing on every sealing job. If our mastic fails or a pinhole reopens within a year, we return and make it right at no charge, including a free second visit.
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 your Duct Sealing in Universal City. Our technicians are background-checked and uniformed. You know who’s walking into your home before they arrive.
We understand the local housing stock. The mid-century ranches near Randolph AFB, the slab-on-grade foundations, the original galvanized ducts with decades of condensation damage. We’ve sealed ducts in the Garden Ridge area, along Universal City Boulevard, and in the older neighborhoods where housing turnover from military PCS moves means new families inheriting duct problems they didn’t create.
HVAC Duct Sealing in Universal City
HVAC Duct Sealing in Universal City means closing the leaks that let conditioned air escape into your attic, crawl space, or wall cavities, and stopping unconditioned air from being pulled into your system. In this market, we see two completely different jobs: sealing pinholes and rusted seams in 50-year-old galvanized steel trunk lines, or resealing disconnected flex-duct runs in newer homes where tape has dried and failed. A typical HVAC duct sealing job in Universal City runs $450 – $950 for partial sealing of problem areas, or $800 – $1,200 for comprehensive whole-home sealing including return-side chase correction.
Most Universal City homeowners don’t realize how much air they’re losing until we run a pressure test. In the older base-adjacent housing, we regularly find 20 – 30% airflow loss before we even open the mastic bucket.
Supply-Side Sealing
Supply ducts carry cooled air from your handler to your rooms. In Universal City’s 1955 – 1975 ranches, these are often galvanized steel with rust pinholes at every low elbow where condensation pooled for decades. We seal with mastic and reinforcing mesh, not tape, because tape fails in attic heat. The price for supply-side sealing alone typically runs $350 – $650.
Return-Side Correction
The return side pulls air back to your handler to be cooled again. In older Universal City homes, this is where we find the real problems. Many return-air chases were built into wall cavities with zero sealing, so your blower is sucking 140-degree attic air and dust straight into your living space. Sealing these chases properly requires opening the chase, applying mastic to all penetrations, and often installing a proper ducted return. This correction alone runs $400 – $800 but changes system performance more than any supply work.
Duct Repair in Universal City
Duct Repair in Universal City addresses the physical damage that sealing alone won’t fix: crushed flex runs, rusted-out galvanized sections, disconnected joints, and return chases that were never properly built in the first place. We don’t just seal over damage. We cut out failed sections and install new material. A typical duct repair in Universal City runs $300 – $700 for localized fixes, or $600 – $1,400 if we’re replacing significant trunk line sections and rebalancing the system.
Repair and sealing often go together. There’s no point in mastic over a rusted-through elbow that will fail structurally within a year.
Galvanized Replacement Sections
When we find galvanized steel that’s too far gone, we cut out the failed section and splice in new ductwork. In Universal City’s older homes, this is common at low points in the trunk line where condensation collected for 40 or 50 years. We price these repairs by the linear foot, with typical single-section replacements running $250 – $500 plus sealing.
Flex-Duct Rebuilds
Newer Universal City homes, especially along the Loop 1604 corridor, use flex duct in unconditioned attics. The heat degrades the outer liner, and rodents or careless service technicians crush the runs. We replace with properly sized flex, support it to prevent sagging, and seal every connection with mastic. Single-run replacements typically run $200 – $400; multiple runs push toward $700 – $900.
Trusted Brands We Service in Universal City
We seal and repair duct systems connected to equipment from every major manufacturer, and we stock sealing materials and filtration products from Aprilaire, Abatement Technologies, and Guardsman for Universal City jobs. Our vans carry Rotobrush rotary brush systems for pre-sealing cleaning, and Nikro negative-air machines for jobs where mold or heavy dust is present. We also offer Universal City Dryer Vent Cleaning to reduce fire hazards and improve dryer efficiency. That means no waiting for parts on a standard sealing job. If your system needs a new filter housing sealed or an Aprilaire media cabinet integrated into a repaired return, we handle it in the same visit. Fast turnaround matters in Universal City, especially for military families on tight PCS timelines who need the work done and documented before final housing inspection.
Common Duct Sealing Problems We See in Universal City Homes
- Rusted pinholes in galvanized low elbows. In the 1955 – 1975 ranches near Randolph AFB, decades of condensation have eaten pinholes at every low point in the trunk line. Mastic-only sealing over active rust fails within a season. We clean, treat, and seal properly, or replace the section if the metal is too far gone.
- Open wall-cavity return chases pulling attic air. These homes were built for window units, not central air. The “return” is often just a framed wall cavity open to the attic at top and bottom. Your blower motor pulls 140-degree dust-laden attic air straight into your system. Sealing the chase penetration is the single biggest improvement we can make.
- Crushed flex runs in newer Loop 1604 construction. Flex duct in hot unconditioned attics sags, gets stepped on by service techs, or gets compressed by storage. A crushed 14-inch return flex can choke airflow by 40% and overwork your blower. We replace and properly support.
- Over-sealing undersized window-unit-era trunks. Some contractors seal every joint without checking static pressure. On systems with original undersized trunks, this chokes airflow and burns out blower motors. We measure before and after. Sealing should improve pressure, not create it.
Pricing for Duct Sealing in Universal City, TX
Honest pricing means ranges you can use, not a teaser that doubles at the door. In Universal City’s market, here’s what we see:
- Partial sealing (supply or return, localized): $450 – $750
- Whole-home sealing with return chase correction: $800 – $1,200
- Single duct repair with sealing: $300 – $700
- Multiple repairs plus comprehensive sealing: $900 – $1,400
What moves the price: accessibility (tight attic vs. walk-in), extent of rust damage, whether we need to replace sections versus seal in place, and whether the return chase needs full correction. We inspect, we measure, we write the price down, and that price does not move once work begins. No per-vent pricing, no add-ons at the door. Call (361) 326-5060 for a free estimate.
We Also Serve Cities Near Universal City
Our crews work throughout the northeast San Antonio metro area, including Universal City, Schertz, Converse, Cibolo, and San Antonio proper. Same standards, same written pricing, same 365-Day Done Right Promise at every address.
Serving Universal City, TX - Our Local Coverage Area
We’re based in the Universal City 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 Universal City
Yes, we seal galvanized ducts from the 1960s regularly in Universal City, but we inspect them first. If the metal has active rust and pinholes, mastic alone will fail within a season. We clean the surface, apply rust-inhibiting primer where needed, then seal with mastic and reinforcing mesh. If the metal is too far gone structurally, we cut out the bad section and splice in new ductwork, priced in writing before we start. Call (361) 326-5060 for an inspection.
Your return side is the problem because many 1955 – 1975 base-adjacent homes in Universal City were built with return-air chases framed inside wall cavities, not ducted returns. These chases are open to the attic at multiple points, so your blower pulls hot, dusty, unconditioned attic air straight into your system and living space. Sealing the supply ducts without fixing the return chase leaves your biggest leak untouched. We correct this with mastic-sealed penetrations and proper ducted returns where needed.
Yes. Universal City’s humid subtropical climate means long summers with air conditioning running constantly from May through September, creating continuous condensation inside ductwork. That moisture feeds mold growth and accelerates rust in galvanized steel. High humidity also means any sealing failure is immediately apparent as musty odors or visible mold. We use mold-resistant mastic formulations and check for biological growth during every sealing job in this climate.
We work with military families on tight timelines regularly. We schedule the inspection, provide written pricing, complete the cleaning and sealing, and document before-and-after photos for your housing office. The 365-Day Done Right Promise transfers to the next occupant, so your landlord has coverage too. Call (361) 326-5060 and mention your PCS date; we’ll prioritize scheduling.
Yes, if it’s done wrong. Over-sealing an undersized trunk line designed for window-unit-era airflow can increase static pressure and overwork your blower motor. That’s why we measure static pressure before and after sealing on every Universal City job. Proper sealing improves airflow to your rooms and reduces system strain. Improper sealing chokes the system. We do it by the book, with numbers to prove it.
Written by Roy Castellanos, Owner at Hollis Air Duct Cleaning, serving Universal City since 2004.