You just closed on a Bay Area home. The movers are gone. The HVAC kicks on for the first time — and the air coming through those vents is older than you are.

Previous owners focus on cosmetic repairs for the sale. Paint, landscaping, hardwood refinishing. The lungs of the house — ducts, vents, chimney flue — are the one thing no home inspection requires and no staging photo reveals. This is the cheapest-to-fix mistake in the first 90 days of homeownership, and the one almost everyone skips.

Here's the checklist.

1. Get a duct photo walkthrough before you do anything else

Before paying for any cleaning, ask your technician for photo documentation of the inside of your ducts at pre-service. If you're paying $399 for a deep duct clean, this is free — and it's the single most valuable data point you'll get about the history of your home. You'll see drywall dust from renovations, pet dander from every previous owner, and often construction debris from the original build.

2. Count your vents. Count your returns. Write it down.

Many duct-cleaning companies price per vent; some quote flat for small homes and per-vent over a threshold. Cal Duct Cleaning is flat $399 up to ten vents, then $24.99 per extra vent. Knowing your number up front makes every quote comparable.

3. Measure a baseline

A handheld particle counter runs about $150 at the consumer level. Even better: book a service that includes pre-/post-particle count measurements in the quote. Actual numbers beat vibes every time — and you'll know within 24 hours whether you got what you paid for.

4. Don't book the $69 special

Any air duct cleaning priced at $69–$99 total is a leaf-blower job — it pushes dust around, it doesn't remove any. Real duct cleaning requires HEPA negative-pressure capture, rotary brush agitation on every branch line, and coil/blower sanitization. Anything less is theater.

5. Hit the bundle discount

Bathroom fans, kitchen exhausts, and water-heater flues cost a fraction when added to a duct-cleaning visit vs separately. A bath fan is $49 bundled, $149 standalone. If you're going to do any of them in the next year — do them all at once.

6. Don't skip the UV light — if you have allergies

A $349 in-duct UV lamp kills mold and bacteria as air passes through. It's not magic. It is cheap insurance for anyone with asthma, young kids, or immunocompromised family members. The HVAC field is slowly catching up to the medical field on this one.

7. Plan the next one

After a deep reset, most Bay Area homes don't need another duct clean for 3–5 years. Write the date in your calendar. Mark your filter-change schedule (every 60–90 days). And forget about it until the calendar reminder pops up.

That's the 90-day duct playbook. For chimney and dryer vent checklists, see our 90-day checklist for older homes or book all three services in one visit — book online from $399.