The air duct cleaning industry attracts both legitimate professionals and unscrupulous scammers. This guide helps you identify qualified companies and avoid the costly mistakes that trap thousands of Denver homeowners annually.
Red Flags: Duct Cleaning Scams to Avoid
⚠️ The "$99 Whole House Special" Scam
How It Works: Companies advertise impossibly low prices ($99-$150 for "whole house" cleaning) to get in your door. Once there, technicians use scare tactics—showing you exaggerated contamination, claiming mold growth, or fabricating urgent safety issues—to pressure you into expensive "necessary" upgrades costing $1,500-$3,000.
Why It's a Scam: Professional duct cleaning requires 2-4 hours of labor, specialized equipment costing $15,000-$30,000, HEPA filtration, and trained technicians. The economics make $99 service impossible without massive corner-cutting or deceptive upselling.
What to Do: Avoid any company advertising prices under $250 for residential service. Legitimate companies charge $300-$600 based on home size.
Additional Red Flags
- Door-to-Door Solicitation: Reputable companies don't go door-to-door offering immediate service. This is a classic scam approach
- High-Pressure Tactics: Scare tactics about "dangerous mold" or "failing HVAC" without proper inspection and testing
- No Written Estimates: Refusal to provide itemized written quotes before starting work
- Cash-Only Payment: Demands for cash or immediate full payment before completing service
- Unlicensed/Uninsured: Cannot provide proof of insurance, business licensing, or technician credentials
- Pushy Add-On Sales: Aggressive upselling of "coatings," "sealants," or unnecessary treatments
- No Physical Address: Only provides P.O. box or refuses to share business location
What to Look For: Signs of a Reputable Company
1. NADCA Membership
The National Air Duct Cleaners Association (NADCA) is the industry's leading certification organization. NADCA members must:
- Meet strict equipment and training standards
- Follow NADCA's ACR (Air Systems Cleaning Specialist) Standard
- Maintain proper insurance and business licensing
- Participate in ongoing professional education
- Adhere to NADCA's code of ethics
How to Verify: Visit NADCA.com and search their member directory. Request the company's NADCA member number and verify it's current.
2. Proper Insurance Coverage
Professional companies carry:
- General Liability Insurance: Minimum $1 million coverage protecting your property from accidental damage
- Workers' Compensation: Protects you from liability if technicians are injured on your property
What to Do: Request certificates of insurance before hiring. Verify coverage is current and amounts are adequate.
3. Professional Equipment
Legitimate companies invest in proper equipment:
- HEPA-Filtered Vacuum Systems: Truck-mounted or portable units producing 3,000-10,000+ CFM suction
- Mechanical Agitation Tools: Rotating brushes, air whips, and contact cleaning devices
- Inspection Equipment: Cameras, mirrors, and tools for proper assessment
Red Flag: Companies showing up with only a shop vacuum or basic consumer equipment cannot perform thorough professional cleaning.
4. Transparent Pricing
Reputable companies provide:
- Free, detailed written estimates before starting work
- Itemized pricing showing base service vs. optional add-ons
- Clear explanation of what's included in base price
- No hidden fees or "surprise" charges after inspection
5. Established Business Presence
- Physical business address (not just P.O. box)
- Years in business (5+ years demonstrates stability)
- Online reviews on Google, Yelp, BBB
- Professional website with detailed service information
- Verifiable phone number and business licensing
Essential Questions to Ask Before Hiring
1. "Are you a NADCA member? What's your member number?"
Why Ask: NADCA membership demonstrates commitment to professional standards. Verify the number at NADCA.com.
Red Flag: Evasive answers, claims of "equivalent" certifications, or refusal to provide member number.
2. "Can you provide proof of insurance?"
Why Ask: Protects you from liability and ensures the company is legitimate and established.
Red Flag: Cannot or will not provide certificates of insurance before starting work.
3. "What's included in your base price?"
Why Ask: Ensures you understand exactly what you're paying for and prevents surprise charges.
Red Flag: Vague answers, refusal to provide itemized estimates, or "depends on what we find" responses.
4. "What equipment do you use?"
Why Ask: Professional equipment is essential for thorough cleaning. Companies should explain their vacuum systems and agitation methods.
Red Flag: Mentions only basic equipment, can't describe their process, or dismisses equipment questions as unimportant.
5. "How long have you been in business in Denver?"
Why Ask: Established businesses with local history are more accountable and reliable.
Red Flag: Brand new companies, out-of-state businesses, or franchises with no local presence.
The NADCA Standard: What Professional Service Looks Like
According to NADCA's ACR Standard, professional air duct cleaning should include:
- System Inspection: Thorough assessment before starting work
- Source Removal: Physical removal of contaminants using mechanical agitation and HEPA vacuum
- Complete System Cleaning: All supply ducts, return ducts, registers, grills, and accessible HVAC components
- System Protection: Proper sealing of access points and protection of your home
- Post-Cleaning Verification: Visual inspection or camera documentation of results
What About DIY Duct Cleaning?
While you can vacuum registers and change filters yourself, professional equipment and expertise are necessary for thorough duct cleaning. DIY attempts using shop vacuums and brush kits:
- Cannot generate sufficient vacuum pressure for effective cleaning
- Cannot access main trunk lines or deep ductwork
- Risk damaging ductwork with improper tools
- May actually spread contamination if lacking proper filtration
Focus DIY efforts on regular filter changes and register vacuuming. Leave comprehensive duct cleaning to professionals with proper equipment.
Work with NADCA-Certified Professionals
Air Duct Pros Denver is a proud NADCA member with 10+ years serving Denver homeowners. Our technicians complete 500+ hours of specialized training, we carry $1 million liability insurance, and we provide transparent pricing with no hidden fees.
Get Free Quote Call (720) 397-7267