HVAC and Duct Mold Remediation in New Orleans
A musty smell when the AC kicks on, dark spots around supply vents, or water in the drain pan? In a climate this humid, air conditioners and ducts can grow mold. Describe what you see once, and independent local companies in New Orleans and nearby parishes reply with free quotes.
Get a Free Quote Call (504) 370-1142
Signs of mold in an air handler or ducts
- A musty or dirty-sock smell when the system starts.
- Dark spots or fuzz on supply vents and the ceiling around them.
- Water in or around the drain pan, or a condensate line that backs up.
- Sweating ducts in the attic or under a raised house.
- Visible growth on the coil, blower or the duct liner behind a return grille.
Common causes: a clogged condensate drain, a coil that stays wet, leaky or poorly insulated ducts in a hot attic, and a system that cools without removing enough moisture.
AC runtime, dew points and New Orleans humidity
Air conditioners do two jobs here: they cool and they pull water out of the air. From June through August, the average dew point at the airport is about 72 to 74°F (NOAA 1991–2020 normals). Supply ducts carry air far colder than that, so any duct or vent that touches humid attic or crawl space air can sweat. Wet insulation and duct liner then grow mold.
Runtime matters. A system that cycles on and off in short bursts may cool the house before it has removed much moisture, and indoor humidity creeps above EPA's suggested limit of 60% (ideally 30 to 50%). A unit that sits off for days does no drying at all. After Hurricane Ida in August 2021, all power was lost in Jefferson Parish and outages spread across the New Orleans area (National Hurricane Center). Days without AC in late-summer heat leave a house with nothing pulling moisture out, which is when air handlers, ducts and closets can start to grow mold.
Ducts in many homes run through the attic or under a raised floor. Both places hold hot, humid air for much of the year, so duct seals and insulation matter.
What a licensed contractor typically does
Inspect the system
Open the air handler, check the coil, drain pan and blower, and look inside ducts at returns and supplies.
Fix the moisture
Clear the condensate drain, seal and insulate leaky ducts, and address sizing or airflow problems. That part is often done by an HVAC contractor.
Clean or replace
Clean hard surfaces like the coil, pan and blower. Moldy flexible duct and fibrous duct liner are often replaced rather than cleaned.
Contain and protect
Seal vents during the work so dust doesn't blow into rooms, and clean nearby surfaces where growth spread.
Restart and report
Restart the system, check that it drains, and provide a written report.
If mold also shows on attic decking or insulation, see attic mold removal. The general steps are on the process page.
What HVAC mold work costs
| Item | Typical range | Source |
|---|---|---|
| HVAC / ducts | $3,000–$10,000 | Fixr, Aug 2025 |
| Mold remediation, typical job | $1,500–$9,000 (avg ≈ $3,500) · $1,200–$3,750 (avg ≈ $2,300) | Fixr, Aug 2025 · This Old House, Mar 2026 |
| Air test · surface (tape/swab) test | $500–$700 · $150–$200 | Fixr, Jan 2025 |
Equipment replacement, new ductwork and system resizing are usually priced by an HVAC contractor. Louisiana's LSLBC also licenses mechanical contractors for larger jobs (about $10,000 and up). If equipment or ductwork is replaced, ask the contractor whether a permit is needed; New Orleans and each parish set their own rules. Compare scopes line by line in the mold remediation cost guide.
Health note
EPA and CDC describe mold's main health effects as allergic and irritant reactions, such as a stuffy nose, itchy eyes, coughing or wheezing. People with asthma, allergies or weakened immune systems may be more sensitive. If anyone in the home has symptoms, see a doctor. Because the system moves air through every room, take duct mold seriously if someone in the home is sensitive.
When to call a company and when to do it yourself
You can do some upkeep yourself: change filters on schedule, keep the condensate line clear, wipe light surface spots off a supply vent grille, and run a dehumidifier in rooms that stay damp. EPA's guideline for DIY cleanup is about 10 square feet, and in Louisiana owners and tenants may do their own mold work without a license (R.S. 37:2157).
Inside the air handler and ducts is different. Call for quotes when you see growth on the coil, blower or duct liner, the smell returns after a filter change, or vents keep spotting. Renters should report HVAC mold to the landlord in writing; see mold in rentals and apartments.
Questions to ask before you hire
Louisiana requires a Mold Remediation license from the Louisiana State Licensing Board for Contractors (LSLBC) for mold remediation projects of about $7,500 and up (La. R.S. 37:2150.1). Before you sign, look up the company's license on the LSLBC website.
- The company's LSLBC license number and classification. Look it up on the LSLBC website before you sign.
- A written contract signed and dated by everyone, with the license number, a description of the work, the total price and current insurance certificates (R.S. 37:2159).
- Proof of at least $100,000 in liability insurance and workers' compensation coverage (R.S. 37:2156.1).
- A written report of what was found and what was done (R.S. 37:2158).
- If you want testing, a separate company for it. In Louisiana, a mold remediation contractor may not also do the mold assessment on the same property, or own the company that does (R.S. 37:2158).
- Which parts will be cleaned, which replaced, and who handles the HVAC repairs that fix the moisture.
HVAC and duct mold FAQ
Should I turn off my AC if there's mold in the ducts?
If you can see mold on vents, ducts or the air handler, avoid running the system over it until someone has looked, because the blower can move spores and dust through the house. In a New Orleans summer that is hard, so get it checked quickly and use portable dehumidifiers or window units in the meantime if you can.
Is duct cleaning the same as mold remediation?
Not quite. Routine duct cleaning removes dust. Mold work on an HVAC system usually means fixing the moisture source, cleaning or replacing the moldy parts (often the coil, drain pan, blower or duct liner), and sometimes replacing flexible duct that can't be cleaned. Ask each company exactly which parts it will clean, replace or leave.
How much does HVAC mold remediation cost?
Fixr's August 2025 range for HVAC and duct mold work is $3,000 to $10,000. A small job on one air handler or a few vents can cost less, while replacing ductwork or equipment can cost more. New Orleans-area quotes vary.
Why does my AC smell musty?
A musty smell when the AC starts often comes from a wet coil, a drain pan that doesn't drain, or duct liner that stays damp. It can also come from mold elsewhere in the house that the system is pulling in. A technician can check the coil and pan; an independent inspector can help if the source is unclear.
Do I need a separate company to test my ducts?
In Louisiana, a mold remediation contractor may not also do the mold assessment on the same property, or own the company that does (R.S. 37:2158). If you want testing before or after the work, hire it from a separate company. EPA notes that in most cases, if visible mold growth is present, sampling is unnecessary.
Get HVAC mold quotes in New Orleans
Tell us where the air handler and ducts are (attic, closet or under the house), what you see or smell, and whether there was a power outage, leak or flood. We pass it to independent companies serving New Orleans and the metro, and they reply with quotes.
Describe your situation any time; companies reply on their own schedules. NOLA Mold Remediation is a free quote service, not a mold company. The companies are independent and may pay to receive requests. There is no obligation, and you choose who to hire. Prefer to talk? Call (504) 370-1142
Found mold or a musty smell? Get free quotes.
Describe it once and independent mold companies serving New Orleans and the metro can reply with no-obligation quotes.