What Actually Happens During Air Duct Cleaning
The 8-step process bad companies skip (and why your ducts are still dirty)
Last Tuesday, I watched a "professional" air duct cleaning company work in a house three doors down from mine in Pearland. They pulled up in a white van. Two guys hopped out with a portable vacuum. They were done in 52 minutes.
I knocked on my neighbor's door afterward. "How'd it go?" I asked.
"Great! They were super fast," she said.
Here's the problem: real air duct cleaning takes 3-5 hours minimum. If they finished in under an hour, they didn't actually clean anything. They just made noise, collected money, and left.
I've been a NADCA certified technician for eleven years. I've cleaned 1,400+ homes across Texas. I train new technicians on proper procedures. And I'm tired of watching homeowners pay for incomplete work.
So let me show you exactly what happens during legitimate professional air duct cleaning. Every step. Every tool. Every minute. Complete transparency.
First, Let's Talk About Equipment
Before we get into the process, you need to understand the equipment difference. This is where most companies cut corners.
Compare that to the shop vacuum from Home Depot that cheap companies use: $200 cost, 2-3 inches of pressure, no HEPA filtration, 2-inch hose. It's like comparing a fire truck to a squirt gun.
The Complete 8-Step NADCA Process
This is what professional air duct cleaning looks like when done correctly. Every step matters. Skip one, and the job is incomplete.
Initial Inspection & Documentation
20-30 minutesWhat we do: Before touching anything, we conduct a complete system walkthrough with camera inspection equipment. We photograph or video record the interior condition of accessible ductwork, document contamination levels, and identify any issues.
Why this matters: This creates a baseline. You see exactly what's in your ducts before we start. It also helps us identify mold, pest infestations, or structural damage that might require additional work.
We check:
- All supply vents (usually ceiling or high wall mounted)
- All return vents (typically larger grilles on walls)
- Main trunk lines (the big rectangular ducts)
- Blower compartment accessibility
- Coil accessibility
- System type and layout
During this inspection, we count vents, measure accessible ductwork, and create a cleaning plan specific to your home's system.
Red Flag: Companies That Skip This Step
If a company doesn't inspect before starting, they're guessing. They don't know what they're dealing with. This almost always means incomplete cleaning because they haven't planned properly.
System Protection & Setup
15-20 minutesWhat we do: We protect your home before bringing in equipment. Floor runners from the entry to the furnace. Drop cloths around work areas. Furniture moved away from vents. The truck-mounted vacuum system is positioned outside, and the main vacuum hose (8-10 inches diameter) is run into your home.
Why this matters: Professional work shouldn't damage your home. We treat your space with respect. Plus, proper setup ensures maximum suction power and complete contamination removal.
Our standard protection includes:
- Heavy-duty floor runners on all walking paths
- Drop cloths under work areas
- Furniture protection where needed
- Magnetic vent covers to control airflow
- All tools and equipment organized
The truck system stays running throughout the entire job. That's 3-5 hours of continuous negative pressure pulling contamination out of your ductwork and trapping it in HEPA filters outside.
Supply Duct Cleaning
60-90 minutesWhat we do: Starting with supply ducts (the vents that blow air into rooms), we remove each register, create access holes where needed, and clean every single supply duct using rotary brush tools and vacuum extraction.
Why this matters: Supply ducts carry heated or cooled air into your living spaces. Dust, debris, and allergens accumulate on duct walls. Without mechanical agitation (brushing), that contamination stays stuck even with strong vacuum suction.
For each supply duct:
- Remove register or grille
- Inspect interior with camera
- Insert rotary brush tool
- Brush entire accessible length
- Vacuum loosened debris
- Clean register thoroughly
- Verify cleanliness with camera
In a typical 2,000 sq ft home with 14 supply vents, this process takes 60-90 minutes. Each duct gets individual attention. We're not rushing through—we're doing it right.
Return Duct Cleaning
30-45 minutesWhat we do: Return ducts pull air from your living spaces back to the HVAC system. These are typically larger and fewer in number (usually 2-4 in residential homes), but they accumulate more contamination because they're pulling in all the dust from your home.
Why this matters: Return ducts are often the dirtiest part of the system. They collect dust, pet dander, cooking grease particles, and whatever else is floating in your home's air. Clean returns dramatically improve overall air quality.
Return duct cleaning includes:
- Removing large return grilles
- Accessing return plenum (main collection box)
- Brushing return duct walls
- Vacuuming return plenum interior
- Cleaning filter slot area
- Inspecting for gaps or leaks
Return ducts are where we often find the most visible results. The amount of dust and debris removed from returns is typically shocking to homeowners.
Trunk Line Cleaning
20-30 minutesWhat we do: Main trunk lines are the large rectangular ducts that distribute air from your HVAC unit to smaller branch ducts. We create access points, insert long rotary brushes, and clean the entire trunk line system.
Why this matters: Trunk lines are highways for air distribution. Restriction here affects your entire system's efficiency. Clean trunk lines restore proper airflow velocity and reduce system strain.
Trunk line work involves:
- Identifying main trunk line locations
- Creating access holes (later sealed properly)
- Using extended rotary brush tools
- Cleaning full length of trunks
- Removing accumulated debris
- Sealing access holes with proper materials
Some homes have trunk lines in attics or crawl spaces. We access these areas to ensure complete cleaning.
Blower & Coil Cleaning
30-40 minutesWhat we do: The blower motor and evaporator coil are critical components. We access the blower compartment, clean the fan blades and housing, and clean accessible coil surfaces. This isn't a full HVAC tune-up, but we address what's accessible during duct cleaning.
Why this matters: A dirty blower fan reduces airflow by 25-40%. Dirty coils reduce cooling efficiency and can harbor mold. Cleaning these components is essential for system performance.
Blower and coil work includes:
- Accessing blower compartment safely
- Vacuuming blower fan blades
- Cleaning blower housing interior
- Surface cleaning accessible coil fins
- Checking for mold or contamination
- Inspecting motor and bearings
We don't remove coils or do deep HVAC maintenance—that requires an HVAC technician. But we clean what's accessible and identify issues that need attention.
Dryer Vent Cleaning
20-30 minutesWhat we do: Dryer vent cleaning is included in our complete service. We disconnect the dryer, clean the entire vent line from dryer to exterior, remove lint buildup, and verify proper airflow.
Why this matters: The U.S. Fire Administration reports that 2,900 home fires per year are caused by dryers. Most are preventable with proper vent cleaning. Plus, clean vents reduce drying time by 40-50%.
Dryer vent service includes:
- Disconnecting dryer safely
- Cleaning connection point
- Running rotary brush through entire vent line
- Removing exterior vent cover and cleaning
- Vacuuming all lint accumulation
- Reconnecting dryer properly
- Testing airflow
We remove an average of 2-5 pounds of lint from dryer vents. Some homes with long vent runs or years without cleaning have 10+ pounds of lint buildup.
Sanitization & Final Inspection
20-30 minutesWhat we do: After mechanical cleaning, we apply EPA-registered antimicrobial treatment to ductwork interior surfaces. Then we conduct final camera inspection, document results, and review everything with you.
Why this matters: Sanitization inhibits mold and bacteria growth. The final inspection proves the work was done thoroughly. You see exactly what your ducts look like now compared to before.
Final steps include:
- Applying antimicrobial fog to duct system
- Allowing proper dwell time for treatment
- Final camera inspection of key areas
- Replacing all registers and grilles
- Complete cleanup of work areas
- Before/after photo review with homeowner
- Providing maintenance recommendations
We don't leave until you're satisfied with the results. You get documentation of the work, and we answer any questions about maintaining your system.
Total Time: 3.5 to 5 Hours
When you add up all eight steps, professional air duct cleaning takes 3.5 to 5 hours for a standard 1,500-2,500 square foot home. Larger homes or complex systems take longer.
Here's the complete timeline breakdown:
Initial inspection & documentation with camera
System protection setup, equipment positioning
Supply duct cleaning (all vents individually)
Return duct and plenum cleaning
Trunk line cleaning with access creation
Blower compartment & accessible coil cleaning
Dryer vent complete service
Sanitization application & final inspection
This isn't padding time to justify higher prices. This is how long it actually takes to do the job correctly when following NADCA standards.
What Cheap Companies Skip (And Why It Matters)
Now you understand what complete cleaning involves. Let me show you what corners get cut by companies offering $99 specials or finishing in under 2 hours.
What You Get
- Truck-mounted HEPA system
- All 8 steps completed
- 3-5 hours thorough work
- Before/after documentation
- NADCA certified process
- Licensed & insured
- Written guarantee
What They Skip
- Portable shop vacuum only
- Main returns vacuumed only
- 45-90 minutes total
- No documentation
- No real standards
- Often uninsured
- No guarantees
The difference isn't just quality—it's whether anything was actually cleaned at all. Budget companies vacuum the easy-access returns, make noise for an hour, and leave. Your supply ducts? Still dirty. Your blower? Still caked with dust. Your dryer vent? Never touched.
Then six months later, you're wondering why your allergies didn't improve and your energy bill didn't drop. Because nothing changed. The contamination is still there.
What Happens After Cleaning
Proper air duct cleaning provides immediate and long-term benefits. Here's what you should notice:
Within 24 Hours:
- Less dust settling on furniture and surfaces
- Cleaner smell when HVAC runs
- More consistent airflow from vents
- Quieter system operation
Within 2-4 Weeks:
- Noticeable reduction in allergy symptoms
- Improved temperature consistency between rooms
- Lower energy bills (typically 15-25% reduction)
- HVAC runs less frequently to maintain temperature
Long-Term (3-12 Months):
- Sustained energy savings ($400-700 annually)
- Extended HVAC component lifespan
- Continued reduction in dust accumulation
- Better overall indoor air quality
We track customer results. Homes in Dallas, Houston, and Katy consistently report these improvements within the first month after professional cleaning.
How to Verify They Did It Right
Don't just take a company's word that they cleaned your ducts. Here's how to verify they actually did the work:
During The Job:
- Truck-mounted system visible outside your home
- Large vacuum hose running from truck into house
- Registers being removed and cleaned individually
- Camera inspection offered before and after
- Work taking 3+ hours minimum
After Completion:
- Request before/after photos or video
- Inspect a few vents yourself with flashlight
- Check that registers were actually removed (look for dust lines)
- Verify dryer vent was cleaned (check exterior vent)
- Ask for written documentation of work performed
Legitimate companies welcome verification. We encourage customers to inspect our work. If a company gets defensive or refuses to show documentation, that's a red flag.
See The Process Yourself
We provide complete camera inspection and documentation with every job. You watch on a monitor as we show you your ducts before and after cleaning. Complete transparency from start to finish.
Serving Dallas, Houston, Pearland and 77+ Texas cities with NADCA-certified service.
Schedule Free Inspection: (281) 519-3163