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.
Abatement Technologies Duct Sealing & Repair: The Herndon Owner’s Guide
Abatement Technologies duct sealing and repair in Herndon typically runs $340-$780 for a complete system, depending on how many duct runs need attention and whether we’re sealing accessible joints or cutting into soffits to reach collapsed flex. We stock Abatement Technologies-compatible mastic, foil tape, and mechanical sealants on every truck, and most Herndon jobs are completed in a single visit. Homeowners usually figure out something’s wrong when a room stays cold despite the register blowing, or when their energy bill spikes after a humid Virginia summer forces the system to overwork.
Which Abatement Technologies Models This Applies To
Abatement Technologies builds negative-air machines and containment equipment for remediation and restoration contractors, but their duct sealing components, including the PAS2400 and PAS5000 series portable air scrubbers with integrated duct adapters, use standardized 10-inch and 12-inch collar sizes that mate with residential flex and rigid ductwork throughout Herndon homes. The critical match point is the collar diameter, not the machine model. A PAS2400 with a 10-inch intake collar needs 10-inch flex with a minimum 25-foot run to maintain proper static pressure, while the PAS5000 series typically runs 12-inch.
To identify what you have, check the metal specification tag on the unit housing, usually located near the power cord entry. The tag lists collar diameter, CFM rating, and electrical draw. For OEM seals, Abatement Technologies specifies their own PTFE-coated fabric gaskets, but we’ve found the aftermarket silicone-impregnated fiberglass seals from Ductmate perform identically in Herndon’s humidity and cost roughly 30% less. The one compatibility gotcha: early PAS2400 units, serial numbers below PAS24-18000, used a slightly narrower gasket channel that won’t accept the current standard seal without trimming. We check serial range before quoting.
Signs Your Abatement Technologies Duct Sealing & Repair Is Failing

- Uneven temperatures room-to-room. When a seal fails at a plenum junction, the conditioned air escapes into the attic or crawl space before reaching the register. The thermostat reads satisfied, but the far bedroom never gets its share.
- Dust blowout immediately after the system cycles on. A failed seal at the air handler pulls attic air, insulation fragments, and rodent droppings into the return side. The camera usually shows a dark ring around the joint where the seal has separated.
- Whistling or roaring at startup. Air rushing through a gap smaller than the duct cross-section creates turbulence noise. The pitch changes with fan speed, which distinguishes it from a failing blower motor.
- Condensation on ductwork in summer. Warm, humid attic air entering through a failed seal hits the cold supply duct. In Herndon’s July humidity, this produces visible sweating and eventually mold on the surrounding framing.
- Energy bills climbing without rate changes. A 15% leakage rate at the plenum, which is common with degraded seals after 8-10 years, forces the system to run longer to hit temperature. The homeowner pays to condition their attic.
Before
AfterReplacement Cost & What’s Included
| Scope | Price Range | What’s Included |
|---|---|---|
| Single joint seal (accessible) | $340-$480 | Removal of old sealant, surface prep, new mechanical seal or mastic application, pressure test, photo documentation |
| Multiple joints, same zone | $520-$680 | Full plenum reseal, collar replacement if corroded, smoke pencil verification, before/after photo record |
| Collapsed flex duct replacement + seal | $620-$780 | New insulated flex, mechanical sealant, support strap installation, airflow verification at register |
The range depends on access, not on how we feel about the job. A plenum in an open attic costs less than the same repair above a finished basement ceiling in a Herndon townhome near the Dulles Technology Corridor. Haven Standard Clause 1 applies: the written price you approve is the price on the invoice. The 365-Day Done Right Promise covers labor and materials, including gasket degradation from the thermal cycling that Herndon’s shoulder seasons deliver.
DIY or Call Us?

An owner can safely inspect visible duct joints with a flashlight and look for cracked mastic, separated tape, or gaps where the collar meets the plenum. What you cannot safely do is apply sealant inside a pressurized duct system or replace collapsed flex without confirming the static pressure load your equipment was designed for. Abatement Technologies machines run specific CFM ranges, and an improper seal changes the resistance curve. That can overamp the blower or, in remediation setups, fail to maintain required negative pressure.
We carry Abatement Technologies-compatible seals, collars, and mastic on every truck. Most Herndon repairs are documented, photographed, and completed in two to four hours. Call (571) 520-6317 and we’ll put a written number next to your inspection findings.
FAQs
In Northern Virginia’s climate, with humidity swinging from 35% in winter to 85% in summer, mechanical seals typically hold 10-14 years and mastic applications 8-12 years before thermal cycling causes cracking. Attic installations degrade faster than basement runs due to temperature extremes. Call (571) 520-6317 for an exact quote on replacement, estimates are free.
Surface cracks in mastic can be recoated if the underlying joint is sound and the original sealant isn’t asbestos-containing, which we verify before disturbing anything. Separated mechanical seals or compressed gaskets require full replacement, recoating won’t restore the designed compression. Call (571) 520-6317 for an exact quote, estimates are free.
Most single-joint repairs take 90 minutes to two hours including setup, pressure testing, and photo documentation. A full plenum reseal with multiple collars runs three to four hours. We schedule Herndon jobs with a two-hour arrival window, no “sometime between 8 and 5.” Call (571) 520-6317 for an exact quote, estimates are free.
We carry Abatement Technologies-compatible seals, collars, and mastic compounds sized for their standard 10-inch and 12-inch collars, plus the narrow-channel gaskets for early PAS2400 units. We do not stock complete machines, we’re an independent service provider, not affiliated with Abatement Technologies. Call (571) 520-6317 for an exact quote, estimates are free.
Show the photo first. Then explain what it means. The estimate comes after that. Tomas Reyes built CleanRun on that sequence starting in 2013, and it’s why Herndon homeowners near Elden Street and the historic downtown core call us when they want to see what was actually inside their ducts before anyone talks about price. Every job gets a written price before work starts, a Documented Photo Record of every run when we’re done, and the 365-Day Done Right Promise in writing. The equipment on our trucks includes Rotobrush, Nikro, Abatement Technologies, Honeywell, Aprilaire, and Guardsman, brands you can look up yourself.
If your Abatement Technologies system is showing any of the symptoms above, or you’ve got a competitor’s estimate you want compared, call (571) 520-6317. We’ll put our written number next to theirs, no charge for the second opinion.
Written by Tomas Reyes, Owner, CleanRun Air Duct Cleaning Herndon at CleanRun Air Duct Cleaning Herndon, serving Herndon and nearby areas.




Before
After
Before
After