Duct Cleaning

Duct Cleaning

The Truth About What's Living in Your Ductwork

Your ducts move 1,000 to 2,000 cubic feet of air every minute. That air passes through the same sheet metal channels thousands of times per year. Whatever's in those channels—dust, debris, pet dander, dead skin cells—gets redistributed throughout your home with every cycle.

The duct cleaning industry has a reputation problem. Too many $99 whole-house specials that amount to little more than shoving a vacuum hose into a few registers. Too many scare tactics about toxic mold that doesn't exist. Too many before-and-after photos that don't match the actual house.

Here's what duct cleaning actually does, when it helps, when it doesn't, and how to tell if you're getting real service or theatrical performance.

What's Actually in Your Ducts

We've cleaned thousands of duct systems. Here's what we typically find:

The Common Stuff (90% of Systems)

Dust accumulation: The average home generates 40 pounds of dust per year. Some of that settles in ductwork. After 5-10 years, you might have 1/4 to 1/2 inch of dust coating the bottom of horizontal runs.

Pet hair and dander: If you have pets, their hair migrates into return vents. One golden retriever produces enough loose hair in a year to create visible accumulation in your return plenum.

Construction debris: Homes built in the last 20 years often have sawdust, drywall dust, and insulation fibers from original construction. Remodeling projects add more. We've pulled out wood scraps, wire nuts, nails, and one time, a contractor's sandwich wrapper from 1987.

Dead insects: Spiders, flies, and other bugs enter ducts through gaps and die inside. Not harmful, but their decomposed bodies become airborne particulate.

Skin cells and fibers: Humans shed about 1.5 million skin cells per hour. Clothing fibers break loose constantly. These accumulate over years.

The Less Common Stuff (10% of Systems)

Rodent evidence: Mouse droppings, nesting materials, or worse—deceased mice. This is an actual health concern requiring professional remediation, not just cleaning.

Visible mold growth: Real mold (not just dark dust) requires specific conditions—standing water or persistent humidity above 60% inside the ductwork. It's less common than the industry suggests, but when present, it's serious.

Water damage residue: Flood damage, condensation problems, or humidifier overflows can leave mineral deposits and organic matter that supports microbial growth.

When Duct Cleaning Actually Helps

The EPA's official position: duct cleaning has never been shown to prevent health problems. Studies haven't demonstrated that dirty ducts increase particulate levels in homes versus clean ducts. But that's talking about average cases. Specific situations genuinely benefit:

Clear Indicators for Cleaning

• Post-construction or remodeling: Drywall dust is incredibly fine and penetrates everything.
• New home purchase: You don't know the previous owner's habits.
• Visible mold growth: If you can see mold on sheet metal surfaces inside ducts.
• Rodent infestation: After pest control handles the source, duct cleaning removes droppings and nesting materials.
• Unexplained respiratory symptoms: If occupants experience symptoms only at home, and only when the system runs.
• Visible debris discharge: If registers are blowing visible dust or particles, something's wrong.

Probably Won't Help

General dusty house: Dust enters from doors, windows, clothing, and human activity—not primarily from ducts. Cleaning ducts doesn't reduce household dust in any measurable way.

Allergies without clear cause: Most allergens come from current sources (pets, pollen, dust mites in bedding), not historical duct accumulation.

"It's been X years since cleaning": Time alone isn't an indicator. Some 30-year-old systems are cleaner than some 5-year-old systems.

Energy efficiency claims: Duct cleaning doesn't improve airflow enough to affect efficiency unless ducts are severely restricted. That's extremely rare.

How Real Duct Cleaning Works

A legitimate duct cleaning takes 3-5 hours for an average home. Here's the actual process:

Step 1: System Assessment (30 minutes)

Before touching anything, we inspect access points, duct material, system layout, and contamination type. Sheet metal cleans differently than flex duct. Fiberglass-lined ducts require special care.

Step 2: Negative Pressure Setup (15 minutes)

This is the critical difference between real cleaning and theater. We connect a high-powered vacuum (4,000+ CFM capacity) directly to your main trunk line. This creates negative pressure throughout the entire duct system. Air flows from registers toward the vacuum, containing all dislodged debris. Without negative pressure, you're just stirring up dust.

Signs of proper setup:

• Large diameter (8-10 inch) collection hose
• Truck-mounted or high-capacity portable vacuum
• Visible suction at all registers (tissue paper test)

Step 3: Supply Duct Cleaning (60-90 minutes)

Each supply register gets individual attention: access, agitation with rotating brush or compressed air wand, and progress verification. Average home has 10-15 supply vents, each taking 4-8 minutes.

Step 4: Return Duct Cleaning (45-60 minutes)

Return systems often harbor more debris because larger openings collect more material, return air isn't filtered until it reaches the handler, and grilles are often near floor level.

Step 5: Air Handler Cleaning (30-45 minutes)

Even with good filtration, some debris bypasses. We clean the blower wheel, evaporator coil surface, drain pan, and cabinet interior.

Step 6: Verification and Sanitizing (30 minutes)

Camera inspection shows before-and-after footage. Optional EPA-registered antimicrobial treatment for mold remediation or rodent situations.

Scam Recognition

The duct cleaning industry has genuine bad actors. Here's how to identify them:

Scam Tactic #1: The Mold Scare

How it works: Technician "tests" your ducts and "discovers" dangerous mold requiring expensive remediation.

Protection: If someone claims you have dangerous mold, request laboratory test results. Get a second opinion from a certified industrial hygienist, not another duct cleaning company.

Scam Tactic #2: The Camera Show

How it works: Technician shows you horrifying video of filthy ducts—but it's not your ducts.

Protection: Watch the camera feed entry point. Mark a duct with tape and verify the camera passes your mark. Ask for the footage to keep.

Scam Tactic #3: Hidden Costs

How it works: "Just $99 for the first 10 vents." Then you have 25 vents, plus returns, plus the air handler needs cleaning...

Protection: Get complete written quotes before work begins. "What's the out-the-door price for everything?"

Scam Tactic #4: Creating Problems

How it works: Technician damages something during cleaning, then offers to fix it for a fee.

Protection: Photograph your system before work begins. Document any changes after completion. Reputable companies carry insurance and take responsibility for their work.

How Often Should You Clean?

There's no universal schedule. We recommend inspection-based decisions:

Annual Inspection

Once yearly, pull a few registers and look inside with a flashlight. Check main trunk lines, return plenum, and supply branches. If you see significant accumulation—more than a light dust film—consider cleaning.

Event-Based Cleaning

Clean ducts after: any significant construction or remodeling, moving into a new home, resolving a rodent or pest issue, water damage affecting ductwork, or verifying mold and treating the source.

Time-Based Guidelines

• Every 5-10 years: Reasonable for most homes
• Every 3-5 years: Homes with multiple pets, smokers, or high dust environments
• Never: If inspection shows clean ducts, there's no reason to clean them

The Bottom Line

Duct cleaning isn't magic. It doesn't cure allergies, slash energy bills, or transform your home's air quality. What it does is remove accumulated debris from channels that move air through your living space.

For most homes, that's a reasonable thing to do every several years, or after events that introduce contamination.

The key is getting real service: proper equipment, adequate time, verified results, and honest assessment of what you need versus what someone wants to sell you.

If your ducts are genuinely dirty, we'll clean them properly. If they're not, we'll tell you that too.