Fenton, MO Duct Services Cost Guide — 2025 HVAC Rates

Estimated Read Time: 11 minutes

Not sure what an air duct inspection cost looks like in 2025? If your home has hot and cold rooms, dusty vents, or rising utility bills, a professional inspection can pinpoint the problem fast and prevent bigger repairs. In this guide, we break down current St. Louis pricing, what affects your total, and which add‑ons are worth it. You’ll also learn when to clean, when to seal, and how to get the most value from one visit.

What Is an Air Duct Inspection?

An air duct inspection is a structured check of your supply and return ductwork, registers, and air handler connections. The goal is to find air leaks, kinks, disconnections, blockages, biological growth risks, and code or safety concerns. Done right, the inspection tells you if cleaning, sealing, repairs, or simple adjustments will improve comfort and efficiency.

A complete inspection often includes three parts:

1. Visual survey of accessible ducts, boots, and plenums.
2. Airflow and static pressure readings to flag restrictions.
3. Optional camera or duct leakage testing to quantify problems.

In St. Louis, many older homes have basement duct trunks with long branch runs feeding second‑story rooms. That layout can hide leaks and crushed flex sections that a quick glance won’t catch.

2025 Air Duct Inspection Cost Breakdown

Pricing varies by home size, access, and test level. Typical ranges for the St. Louis metro in 2025:

1. Visual duct inspection only: $99–$199
   • Includes accessible duct survey, photos, and written findings.
2. Visual + camera scope on suspect runs: $200–$450
   • Adds video inspection for hidden obstructions or disconnections.
3. Duct leakage test (pressure‑based): $150–$300 when bundled, $250–$450 stand‑alone
   • Quantifies leakage in CFM and percentage. Essential if you suspect wasted energy or uneven rooms.
4. Whole‑home diagnostic bundle: $249–$599
   • Visual, airflow readings, and leakage test; often paired with a tune‑up discount.

Commercial or multi‑unit properties are priced by scope and access points. Expect a custom quote after a quick call.

What Drives Your Price Up or Down

Several factors shift the total:

1. Home size and number of registers
   • More supply and return points take longer to test and document.
2. Accessibility
   • Tight crawlspaces, plaster‑and‑lath walls, or finished ceilings raise labor time.
3. Duct material and condition
   • Old sheet‑metal trunks with unsealed seams, mixed with aging flex, often require camera work to confirm leaks and kinks.
4. Add‑on diagnostics
   • Camera scoping and duct leakage testing add precision and cost, but they prevent guesswork repairs.
5. Safety or code red flags
   • Signs of back‑drafting, damaged insulation, or unsealed furnace rooms require extra verification.
6. Bundles and maintenance plans
   • Pairing inspection with system maintenance usually lowers the per‑test cost.

Inspection vs. Cleaning vs. Sealing: What Do You Actually Need?

• Choose an inspection when you notice uneven temperatures, dust at registers, or high bills after a season change. It pinpoints cause.
• Choose cleaning when a qualified pro confirms heavy debris, visible biological growth risks, or pest activity. Cleaning without proof is a waste.
• Choose sealing when tests show measurable leakage. Leaky ducts can pull attic or crawlspace air into your home and push conditioned air out.

Hard fact: Studies and field data show that 20 to 30 percent of heating and cooling energy is commonly lost through leaky ductwork, and in some homes it can reach 40 percent. If your leakage test lands in that range, sealing pays back quickly.

Add‑Ons That Are Worth It

1. Duct leakage test
   • If you feel drafts, have rooms that never match the thermostat, or see dust halos around vents, get the test. It turns “I think” into a number you can act on.
2. Camera scope on suspected problem runs
   • Great for finished basements or long second‑floor branches in St. Louis City’s brick bungalows where visual access is limited.
3. Aeroseal duct sealing quote
   • Aeroseal is a patented internal sealing process. Our software measures leakage before and after, so you know exactly what you gained. Typical whole‑home sealing for an average single‑family residence often ranges from $1,800 to $3,500 depending on size and leakage.
4. IAQ upgrades
   • If testing points to dust and infiltration, consider an air purifier or UV system during the same visit to save a trip charge.

What Happens During Our Duct Inspection

Here is our standard approach for homeowners around St. Louis, St. Charles, O’Fallon, and Belleville:

1. Discovery
   • We review your symptoms, utility history, and comfort hotspots.
2. Visual assessment
   • We examine trunks, branches, boots, and connections at the air handler. We note insulation gaps and unsealed seams.
3. Airflow and pressure checks
   • Readings at supply and return highlight undersized runs or restrictions.
4. Optional leakage test
   • We pressurize the duct system to quantify leakage in CFM and percent. Results guide next‑step decisions.
5. Findings and options
   • You get a clear report with photos. If sealing is recommended, we explain expected results. With Aeroseal, our software shows leakage before and after so you see the improvement.

Hard fact: Aeroseal is a patented technology that seals from the inside. Pressurized air carries safe sealing particles that adhere at leak edges until the opening is closed. The result is verified in real time by the software.

Signs You Should Schedule Now

• One or two rooms stay 3–6 degrees off target.
• Dust collects quickly on flat surfaces and around supply registers.
• Vents whistle or you hear air rushing behind walls.
• You added a finished space and comfort got worse.
• Your winter gas bill or summer electric bill spiked without a weather reason.

If you checked two or more, book an inspection. In many St. Louis two‑story homes, upper bedrooms expose duct leakage and balance problems first.

Local Pricing Context: St. Louis Metro

Older clay‑tile basements, narrow utility rooms in University City, and crawlspaces common in St. Charles County make access a big cost driver. Homes in O’Fallon and Wentzville with long upstairs runs often benefit from a leakage test plus camera scope. We price transparently based on time and test complexity, then credit part of that if you proceed with sealing or approved repairs.

Sample Estimates for Common Scenarios

1. Small ranch, 8–10 registers, easy basement access
   • Visual + airflow: $129–$179
   • Add leakage test: +$150–$200
2. Two‑story, 14–18 registers, finished basement
   • Visual + airflow: $159–$229
   • Add camera on two branches: +$120–$200
   • Add leakage test: +$175–$250
3. 1920s city bungalow, plaster walls, mixed metal and flex
   • Visual + airflow: $149–$199
   • Camera on three branches: +$180–$250
   • Likely sealing if leakage >25%: Aeroseal estimate typically $1,800–$3,200

These are planning ranges. Your written quote reflects your exact layout and test menu.

Will Insurance or Rebates Help?

• Homeowners insurance rarely covers inspections unless linked to a covered peril.
• Utility and manufacturer programs sometimes offer incentives for duct sealing or IAQ improvements. We help you check current promotions at the time of your visit.
• Our Preferred Partner Plan can reduce diagnostic costs and provide priority scheduling during peak seasons.

DIY Checks Before You Call

• Replace or upgrade your filter and note airflow changes.
• Look for dust trails at supply registers and around return grills.
• Inspect visible seams on basement trunks and note any gaps.
• Photograph suspect areas so we can scope faster.

If you still have uneven rooms or visible gaps, schedule a professional inspection with testing. Guesswork repairs can cost more than a proper diagnosis.

How to Choose the Right Pro in 2025

• Ask for a written, line‑item quote that separates visual, camera, and leakage testing.
• Confirm the company is licensed and insured, and that technicians follow local codes.
• Look for recognized credentials and awards. We are a Carrier Factory Authorized Dealer and a multi‑year Carrier President’s Award recipient.
• Expect data. A good inspection includes photos, readings, and clear next steps.
• Prioritize cleanliness and protection. Shoe covers, drop cloths, and careful routing matter in finished spaces.

After the Inspection: Payback and Next Steps

If your ducts leak 20–30 percent, sealing and minor repairs can deliver faster warm‑up, quieter airflow, and lower bills. Our Aeroseal option verifies results in software, so you see leakage drop as the seal takes hold. Pairing sealing with a proper system tune‑up often yields the best seasonal comfort for St. Louis weather swings.

Service Areas

We serve homeowners across Greater St. Louis, including:

• St. Louis, St. Charles, St. Peters, O’Fallon, Florissant, Chesterfield, Wentzville, Alton, Columbia, and Belleville.

Wherever you live in the metro, we can schedule your inspection quickly and provide a same‑day written estimate.

What Homeowners Are Saying

"Technician installed an Air Scrubber on our AC ductwork. As usual with this company the service was outstanding and very professional. I would recommend them to anyone."
–Jack E., St. Louis

"Professional, on time, gave me bids for other suggested work before he left. Found a hole in my duct which could have caused carbon monoxide poisoning this winter-repaired it right away."
–Lisa M., St. Charles

"Ethan installed an Aeros Air Scrubber on my home HVAC system today. Prompt, courteous and professional. Looking forward to better indoor air quality. I have been a customer of Air Comfort Service for over 26 years. Great service always!"
–Mike S., O’Fallon

"Logan was very kind and professional checking and preparing our heating system. He even did cleaning and checking air conditioner as a added service. We are very pleased with Air Comfort Service Inc! Mike"
–Michael S., Belleville

Frequently Asked Questions

How much does a basic air duct inspection cost in 2025?

Expect $99–$199 for a visual inspection in the St. Louis area. Adding a camera scope or a duct leakage test increases the total but delivers more precise findings.

Is a duct leakage test worth the extra cost?

Yes if you have uneven rooms, noisy vents, or high bills. The test quantifies leakage in CFM and percentage, so you can target sealing with clear ROI.

Do I need duct cleaning or sealing after an inspection?

Only if the inspection confirms a problem. Cleaning addresses debris. Sealing fixes leakage. Many homes benefit more from sealing than cleaning.

How long does an inspection take?

Most homes take 60–120 minutes for a visual and airflow check. Add 45–90 minutes for camera and leakage testing, depending on access and size.

Will Aeroseal sealing be quoted at the same visit?

If testing shows meaningful leakage, we can provide an Aeroseal quote on the spot and explain expected results using our before‑and‑after software readings.

Conclusion

A professional duct inspection reveals what guesswork misses and helps you invest wisely. In 2025, most St. Louis homeowners spend $99–$199 for a visual inspection and $249–$599 for full diagnostics. If leakage is the culprit, sealing can recover lost comfort and efficiency fast.

Call to Schedule Your Duct Inspection

Ready to get clear answers and honest pricing? Call Air Comfort Service, Inc. at 314‑814‑8455 or schedule online at https://www.aircomfortservice.com/. Ask about current diagnostic bundles. If sealing is recommended, we apply your test results toward a verified solution that improves comfort room by room.

Call 314‑814‑8455 or book at https://www.aircomfortservice.com/ for your 2025 duct inspection. Get a written, line‑item quote and same‑day results you can act on.

Air Comfort Service, Inc. has served Greater St. Louis since 1969. We’re a Carrier Factory Authorized Dealer and multi‑year Carrier President’s Award winner. Our licensed technicians follow local codes, pull permits when required, and protect your home with clean‑work practices. We offer 24/7 service, honest pricing, and a Preferred Partner Plan with priority scheduling and repair discounts. From IAQ upgrades to Aeroseal duct sealing, we deliver precise, code‑compliant work backed by decades of local experience.