Duct cleaning isn’t something you buy every month, so it’s easy to feel unsure about who to hire. In Guelph—where we deal with humid summers, salty winter air, and pollen-heavy springs—the right company can noticeably cut dust, reduce musty odours, and help your HVAC run smoother. The wrong one? A quick vacuum of a few vents, a big bill, and no real change. Use this practical checklist to hire confidently and get results you can actually feel.

1) Confirm the Company’s Credentials

Why it matters: Proper insurance and training protect your home and the technicians working in it.

Checklist

• Commercial general liability insurance (ask for proof)
• WSIB coverage for Ontario
• Evidence of technician training (NADCA, HRAI, or manufacturer-specific)
• Years in business and local references in Guelph (Kortright Hills, Downtown, Exhibition Park, Westminster Woods)

Red flag: Vague answers like “we’re fully covered” without documentation.

2) Understand the Cleaning Method (Process Beats Promises)

Why it matters: Real results require source removal, not just “blowing dust around.”

Look for

• Negative air (vacuum) setup attached to the trunk lines
• Mechanical agitation (rotary brush or air whip) for each branch line
• Return and supply trunks cleaned, not just registers
• Furnace cabinet and blower compartment addressed (key for airflow)
• HEPA filtration/containment to keep debris out of living areas

Ask: “Can you describe, step by step, how you clean my system from the furnace cabinet to the farthest branch?”

3) Demand Before-and-After Photos

Why it matters: Photos verify that debris was actually removed from inside the ducts you don’t see.

Checklist

• Photos of representative supply/return branches before starting
• Photos of trunks and the furnace cabinet after completion
• Same angles, clearly labeled
• Short video if a line is especially clogged or damaged

Red flag: “We don’t do photos.” In 2025, every tech has a camera.

4) Get an Itemised, All-In Quote (No Surprise Add-Ons)

Why it matters: Low teaser prices often balloon at the door.

Your quote should include

• Number of supply registers and returns covered
• Inclusion of trunk lines and furnace cabinet
• Pricing for add-ons (dryer vent, AC coil face clean, sanitizer)
• HST, travel, parking/driveway considerations
• Estimated duration and how extra vents are billed (with a per-vent price)

Tip: For typical Guelph single-family homes, a full-system clean usually takes 2–4 hours with two techs. If a company quotes 60 minutes, expect a superficial job.

5) Ask About House Protection & Clean-Up

Why it matters: Good results shouldn’t come with a mess.

Minimum standards

• Shoe covers and drop sheets around each register
• Corner guards on stairs and tight turns
• Register screws placed in a container (not on the floor)
• Vacuum or wipe-down where work occurred
• Doors and windows managed to keep heat/AC in during winter/summer

Red flag: No mention of containment or protection materials.

6) Check Equipment Quality

Why it matters: Undersized vacuums and weak compressors won’t move packed debris.

Look for

• Truck-mounted or high-CFM portable negative-air machines
• Rotary brush or air whip agitation tools sized for your duct type
• Dedicated HEPA vacs for registers and furnace cabinet
• Access tools for creating proper service openings (with code-compliant closure plates)

Good question: “What’s the CFM of your negative-air machine, and how do you verify adequate suction at the far branches?”

7) Verify Scope Beyond “Ducts”

Why it matters: Air quality isn’t just about the metal (or flex) in your walls.

Smart inclusions

• Filter fit check and MERV guidance matched to your blower
• Visual check for return-side leaks (common in basements)
• Humidifier pad condition and seasonal settings
• Dryer vent inspection/cleaning (major safety item)
• Notation of crushed flex runs, disconnected branches, or missing filter rack gaskets

Outcome: You should receive notes that help you prevent dust from coming back.

8) Ask About Sanitizers and Fragrances (Evidence Over Aroma)

Why it matters: Not every system needs chemical treatment.

Best practice

• Sanitizers applied only when justified (post-reno, odour/bacterial issues, pests)
• Clear explanation of the product, dwell time, and ventilation
• Option to decline fragrances and “fresheners” that just mask issues

Red flag: Hard sell on chemicals without a reason.

9) Timing That Fits Guelph’s Seasons

Why it matters: When you clean affects how long results last.

Local timing tips

• Early spring: Clear winter dust and pet dander before open-window season.
• Mid-summer: Post-pollen reset—especially near tree-lined streets and the Speed River corridor.
• Early fall: Pre-heat clean to avoid blowing construction dust when the furnace kicks on.

Allergy note: Schedule 1–2 weeks after peak pollen for longer relief.

10) Read Reviews Like a Pro

Why it matters: Recent, specific feedback predicts your experience.

Filter for

• Newest reviews (last 6–12 months)
• Mentions of punctuality, cleanliness, and photo proof
• Technicians praised by name (consistency)
• Honest experiences in neighbourhoods like Grange Hill East, Old University, Clairfields

Beware: Repeated complaints about price increases at the door or “was in and out in an hour.”

11) Confirm Warranty and Follow-Up Support

Why it matters: Good companies stand behind their work.

Expect

• A workmanship window (e.g., 14–30 days) to report concerns
• Clear point of contact for questions
• Guidance on filter changes and maintenance cadence (often 2–4 years depending on pets, renos, allergies)

Pro move: Ask for a simple one-page post-service report summarising what was found and fixed.

Quick, Printable Hiring Checklist

• Proof of insurance, WSIB, training/affiliations
• Step-by-step process explained (negative air + agitation + trunks + cabinet)
• Before/after photo commitment
• Itemised, all-in quote (vents, trunks, add-ons, HST)
• House protection plan and clean-up standards
• High-CFM equipment and proper agitation tools
• IAQ extras checked (filter fit, returns, humidifier, dryer vent)
• Sensible sanitizer policy (only if needed)
• Seasonal timing aligned to your needs
• Recent, specific local reviews
• Warranty/follow-up and a post-service summary

Bottom Line

Hiring a duct cleaning company in Guelph shouldn’t be guesswork. Choose a provider that explains their method, proves results with photos, protects your home, and prices transparently. When those boxes are ticked, you’ll hear smoother airflow, see less dust, and feel better breathing—proof that the job was done right, not just “done.”