After water gets into the ducts, stop the water, do not run an HVAC system that got wet, and dry the space fast. Mold can grow on wet materials in about 24 hours (EPA). Once the house is dry, whole-home disinfection for mold is $0.30 per heated square foot ($200 minimum). Vents are $50 each on the same visit, or from $399 alone. 12-month written guarantee.
See your price
- Whole-home disinfection: $0.30 per heated sq ft ($200 minimum)
- Clean the vents on the same visit: $50 each (no extra minimum)
- Both include Bactronizing with BactroKill Plus + 12-month written guarantee
Not sure what you need?
Start with the vents
A smell that rides the air is growing in the duct work. We scrub each vent and return with a rotary brush, clean the registers, the coil and the outside of the air handler, then treat them. $50 a vent, from $399 on its own. Spores travel on the air, so most people add the whole-home disinfection on the same visit, and then the vents carry no minimum. 12-month written guarantee.
Start with the whole home
A smell that sits in the rooms, or came with the last people, is on the surfaces, not only in the air. Whole-home disinfection sprays every surface in the house, closets included, plus the duct work and the drain pan: $0.30 per heated square foot, $200 minimum, about 30 to 75 minutes, and you can stay home. Dust or growth in the vents needs cleaning first, so add the air duct cleaning at $50 each on the same visit if the vents are dirty. 12-month written guarantee.
We look first
Mold you can see gets wiped off, not sprayed over. Every one is different, so we look before we price it, and Greg puts the price in writing before any work starts.
Fix the water first
Mold is a water problem first. Wet material grows again, so the leak, the flood or the drain line gets fixed before anything is sprayed. Once it is dry we treat it, and if something is still wet we say so before we start.
Two ways to be sure
If you can smell it or see it, the CDC says you do not need to know the type, so most people skip the test and treat. To be sure anyway: while we are at the house we can swab a surface and read it on a hand-held meter, or send samples to a lab, $350 for two and $450 for four.
Request a window Or start with the treatment Call 843-282-7777
Open now. Closes at 4 pm.
Call 843-282-7777Request a windowGreg confirms it in writing.Do not know the square footage? Request a visit without a number. We work it out when we come out.
Veteran owned. Licensed and insured. EPA-registered product. 12-month written guarantee.
What should I do first if water got into my HVAC or ducts?
Move in this order. Speed matters, because the EPA states mold can grow on wet wood, drywall, carpet, and furniture if they stay wet for more than 24 hours.
- Stop the water and stay safe. Cut the source if you can. If water touched electrical or the air handler, kill power at the breaker before you go near it.
- Do not run the HVAC if any part of it got wet. The EPA is direct: “If any part of your HVAC system was affected by the flood, do not use it to help dry out your house.” Running it can blow spores and moisture through every room.
- Dry the space fast. Open it up, run fans and a dehumidifier, pull out soaked materials. Drying a flooded home usually takes “several days to weeks” (EPA), so start now.
- Photograph everything before you clean. Date-stamped photos of standing water, wet ductwork, and damaged contents are what an insurance adjuster will ask for. Document first, clean second.
- Get the system inspected and treated once it is dry. Mold does not need standing water to keep going, only damp surfaces. Have the house and the duct system checked, cleaned and treated before you put the system back in service.
See your price. It asks for the heated square feet of the house, and a vent count too if you want the ducts done on the same visit.
How quickly can mold grow in ducts after water gets in?
Fast. The EPA states mold can grow on wet wood, drywall, carpet, and furniture if they stay wet for more than 24 hours, and a damp, dark duct system in the Lowcountry’s humidity, about 72 percent on average (WeatherSpark climate summary for Charleston), is close to ideal for it. That is why the first 24 to 48 hours of drying matter more than anything you do later.
The clock does not stop when the visible water is gone. Surfaces that feel dry can hold enough moisture inside ductwork, insulation, and the air handler to keep mold going for days. Source: EPA, Flood Cleanup to Protect Indoor Air and Your Health; humidity figure is a Charleston, SC area annual average (WeatherSpark, secondary aggregator).
Should I turn my HVAC back on after a flood?
No, not if any part of it got wet, and not until it has been inspected and dried. The EPA is explicit: “If any part of your HVAC system was affected by the flood, do not use it to help dry out your house.” A wet system that you switch on can push mold spores and damp air into rooms that were never flooded.
The EPA also notes that “cleaning and drying your HVAC system can be complicated, so it is best to have a professional do it.” Use stand-alone fans and a dehumidifier to dry the house, not the central system, until a pro has cleared it.
What does the EPA recommend for HVAC after flooding?
Fix the moisture first, then handle the system. The EPA’s whole framing is that “the key to mold control is moisture control”: dry the structure before you reassemble or treat anything, because treating over a wet system just feeds the mold again. It also warns not to seal or paint wall cavities and surfaces “until you are sure the materials are completely dry on the inside.”
For the ducts themselves, the EPA points homeowners to professional cleaning when “the air ducts in your HVAC system have become contaminated.” That is the order we follow: dry, clean, then treat. Sources: EPA, Flood Cleanup to Protect Indoor Air and Your Health; EPA, A Brief Guide to Mold, Moisture and Your Home.
Which parts of the duct system can be treated, and which must be replaced?
Hard surfaces can usually be cleaned and treated. Porous materials that stayed soaked often cannot.
- Metal ducts, the registers, the coil, and the air-handler housing: non-porous, so these are cleaned and antimicrobial-treated, not replaced.
- Fiberglass duct board, internal duct liner, and porous insulation that was saturated: the EPA’s position on wet porous materials is that they often cannot be fully cleaned and may need to be removed. If that material soaked, replacement is the honest call.
- Flex duct that filled with water: judged case by case. If it dries clean it can be treated; if it held standing water, it usually comes out.
We tell you which bucket your system falls into before any work, and we do not treat over material that should be replaced. Source: EPA, Mold Remediation in Schools and Commercial Buildings (porous-materials guidance).
How do I know if the mold is in the ducts or just on the vent covers?
Vent-cover mold is what you can see and wipe: dark speckling on the louvers and the wall around the register, often just surface condensation. Mold deeper in the system is what you cannot see, and it usually shows up as a musty smell that gets stronger as soon as the system starts running, spots that come back days after you wipe the covers, or visible growth when you pull a register and look inside the duct.
If wiping the covers does not kill the smell, or it returns within a day or two, the source is deeper than the grille. After a water event, assume the system needs a look inside, not just a wipe-down.
How does an antimicrobial treatment fit into flood recovery, and what does it cost?
It is the last step, after the water is fixed and the house is dry. The work is two jobs, usually done on one visit.
Whole-home disinfection is $0.30 per heated square foot with a $200 minimum. After a water event it is usually the right shape, because water rarely stops at the ductwork. BactroKill Plus, an EPA-registered product (EPA Reg. No. 82972-1-90746), goes through the house room by room with an electrostatic sprayer. Bactronix calls that process Bactronizing. Closets are in it, and the garage is in it when its footage is in the number you give us.
air duct cleaning and treatment is $50 a vent on the same visit, however many you have, with no extra minimum. We clean, then treat, the registers, the duct work, the coil and the outside of the air handler. If the ducts are the only thing water reached, air duct cleaning and treatment on its own starts at $399.
A whole-home disinfection takes about 30 minutes at 1,500 square feet, 45 at 2,500 and 75 at 3,500. You can stay in the house. Keep people and pets out of a room while we spray it. It is yours again 15 minutes later. No trip charge. You pay on the day.
Greg Busang owns Bactronix of the Lowcountry. We work to the EPA’s order of operations: dry, then clean, then treat. Nothing gets added on site.
That is a different scope, and a different number, from conventional mold removal inside an HVAC system, which runs $2,000 to $10,000 nationally (HomeGuide 2026, This Old House 2026; national estimate, Charleston SC area). If the water damage went structural, we say so. This is treatment. It is not structural mold remediation, it does not fix an active leak, and moisture that is still wet can grow mold again.
Will my treatment hold if the moisture source isn’t fixed?
No, and we will tell you that before we take the job. The EPA’s rule is “the key to mold control is moisture control,” so if the leak, the flood path, or the standing humidity is still there, the mold comes back no matter what we spray. We treat the system, but the moisture has to be fixed too.
That is also how the guarantee works. We find and call out the moisture source as part of the job. The guarantee goes on the invoice in writing: if what we treated comes back inside 12 months, we come back and re-treat it at no charge. The one exclusion is an area where new water has come in since, because new water grows new mold.
When should a professional handle it, and will insurance cover it?
Call a pro when water reached the air handler or ducts, when the musty smell returns after you clean the covers, or when porous material soaked and may need to come out. The EPA itself says cleaning and drying an HVAC system “can be complicated, so it is best to have a professional do it.” A wet central system is not a wipe-and-go DIY.
On insurance: it is case by case, and we do not promise coverage. Sudden, accidental water (a burst pipe, storm intrusion) is more often covered than gradual leaks or flood water, which many policies exclude without separate flood insurance. Photograph the damage before you clean, call your carrier early, and let them confirm what your policy covers. We give you a clear, itemized treatment price either way.
Where we work
We work the Lowcountry: Cane Bay, Nexton, Carnes Crossroads, Summerville, Goose Creek, Moncks Corner, and the wider Charleston area. Storm and water events hit this region hard.
The room-by-room job is set out on whole-home disinfection, and the air-system job is on air duct cleaning and treatment. If the musty smell is what tipped you off, see why your AC smells musty.
Frequently asked questions
How quickly can mold grow in ducts after water gets in?
Fast. The EPA states mold can grow on wet wood, drywall, carpet, and furniture if they stay wet for more than 24 hours, and a damp, dark duct system in the Lowcountry’s humid air is close to ideal for it. That is why the first 24 to 48 hours of drying matter most. Surfaces that feel dry can still hold enough moisture inside ductwork to keep mold going for days.
Should I turn my HVAC back on after a flood?
No, not if any part of it got wet, and not until it has been inspected and dried. The EPA is explicit: “If any part of your HVAC system was affected by the flood, do not use it to help dry out your house.” A wet system you switch on can push mold spores and damp air into rooms that were never flooded. Use stand-alone fans and a dehumidifier instead until a pro clears it.
What does the EPA recommend for HVAC after flooding?
Fix the moisture first, then handle the system. The EPA’s framing is that “the key to mold control is moisture control”: dry the structure before you treat anything, because treating over a wet system just feeds the mold again. For contaminated ducts, the EPA points homeowners to professional cleaning. The order we follow is dry, clean, then treat.
Which parts of the duct system can be treated, and which must be replaced?
Hard surfaces can usually be cleaned and treated: metal ducts, the registers, the coil, and the air-handler housing. Porous materials that stayed soaked often cannot, and the EPA’s position is that saturated porous material may need to be removed. Saturated fiberglass duct board, internal liner, and water-filled flex duct are judged case by case. We tell you which bucket your system falls into before any work.
How do I know if the mold is in the ducts or just on the vent covers?
Vent-cover mold is what you can see and wipe: dark speckling on the louvers and the wall around the register. Mold deeper in the system shows up as a musty smell that gets stronger when the system runs, spots that return days after you wipe, or visible growth when you pull a register and look inside. If wiping the covers does not kill the smell, the source is deeper than the grille.
What does treatment cost after a water event?
Whole-home disinfection for mold is $0.30 per heated square foot with a $200 minimum, and after a flood that is usually the right shape because water rarely stops at the ductwork. Air duct cleaning and treatment is $50 a vent on the same visit, however many you have, with no extra minimum. If the ducts are the only thing water reached, air duct cleaning and treatment on its own starts at $399. Everything carries a 12-month written guarantee.
Will my treatment hold if the moisture source isn't fixed?
No, and we tell you that before we take the job. The EPA’s rule is “the key to mold control is moisture control,” so if the leak, flood path, or standing humidity is still there, the mold comes back no matter what we spray. We find and call out the moisture source as part of the job. If treated mold returns inside 12 months and the moisture was handled, we come back and re-treat at no charge.
When should a professional handle it, and will insurance cover it?
Call a pro when water reached the air handler or ducts, when the smell returns after you clean the covers, or when porous material soaked. The EPA says cleaning and drying an HVAC system is best left to a professional. On insurance, it is case by case and we do not promise coverage: sudden accidental water is more often covered than gradual leaks or flood water. Photograph the damage before you clean and call your carrier early.
Request a window
Put the heated square feet in above, and the vent count too if the ducts need doing. Pick the day and window that suit you, and we call or write back to lock in the time.