A musty smell when your Summerville AC turns on almost always means mold in the HVAC system. Humid Lowcountry air condenses on the cold coil and ductwork and feeds it, and the system carries the smell into every room. 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
I think it's mold. What do I do?
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.
From Old Town’s historic homes to the new builds in Nexton and Cane Bay, Summerville runs humid, and humid air grows mold inside HVAC ductwork. We serve all of Summerville, ZIP codes 29483 and 29485, plus surrounding Dorchester and Berkeley County.
Where does the musty smell in a Summerville home come from?
Summerville sits on a pocket of pine, oak, and moisture. The town runs humid roughly six months a year, with relative humidity about 72 percent on average (WeatherSpark climate summary for Charleston). The EPA recommends keeping indoor humidity between 30 and 50 percent, and below 60 percent at the outside, since mold growth is associated with higher humidity. Its own summary is four words: “the key to mold control is moisture control.” Summerville sits over that line for half the year.
Old Town and pre-2000 homes have ductwork that has been pulling tannins, dust, and damp air through the same returns for decades. Older sheet-metal trunk lines hold moisture in their joints.
New builds in Nexton and Cane Bay get the same treatment. The EPA names condensation on or near the cooling coil as a major factor in moisture contamination of an air system (EPA, Should You Have the Air Ducts in Your Home Cleaned?), whatever the age of the house.
Either way, the first sign is the same. A musty smell when the air conditioner starts. If you want the full diagnostic, read why does my AC smell musty.
Treating mold in Old Town Summerville’s historic homes
Summerville’s historic district has homes dating to the late 1800s, and the original plaster, heart-pine floors and millwork are the reason people restore them. Whole-home disinfection does not touch any of it. BactroKill Plus, an EPA-registered product, goes through the house room by room with an electrostatic sprayer. Nothing gets cut open and nothing gets stripped. Keep people and pets out of a room while we spray it. It is yours again 15 minutes later.
Where the ductwork is the source, that is the air duct cleaning and treatment. Old sheet-metal trunk lines hold moisture in their joints, so the surfaces get cleaned first and treated after.
How much does mold treatment cost in Summerville?
Whole-home disinfection is $0.30 for every heated square foot, the same rate on an Old Town cottage and a Nexton four-bedroom, with a $200 minimum and a 12-month written guarantee. Your square footage is the only thing you need to get a price. Nobody measures anything: the square footage is on your county record and on the listing if you bought the house.
An 1890s Old Town cottage and a 2022 Nexton build of the same size pay the same. The rule is the size of the house, not its age or its ZIP code.
| Service | Price |
|---|---|
| Whole-home disinfection | $0.30 per heated square foot, $200 minimum |
| Vents added to a whole-home job, same visit | $50 a vent, however many you have |
| Vents booked on their own | $50 a vent, starting at $399 |
| Dryer vent, added to the same visit | $50 |
| Dryer vent, booked on its own | $99 |
| Conventional HVAC-system mold removal (a different job) | $2,000 to $10,000 (national estimate, Charleston SC area: HomeGuide 2026, This Old House 2026) |
| Conventional whole-home remediation (a different job) | $1,200 to $3,750+ (national estimate, Charleston SC area) |
The bottom two rows are not our prices and not our scope. They are what national sources quote to remediate mold once it is established, in an HVAC system or through a house (HomeGuide 2026; This Old House 2026, national estimates for the Charleston SC area). Treating early is the affordable step before it gets there. For the full breakdown, see HVAC mold treatment cost.
Time at the house runs about 30 minutes at 1,500 square feet, 45 at 2,500 and 75 at 3,500. You can stay in the house while we work, keeping people and pets out of the room we are spraying. No trip charge. You pay on the day.
On air duct cleaning and treatment the list is fixed: the supply and return vents, the duct work, the cooling coil and the outside of the air handler. They are cleaned, then treated with BactroKill Plus (EPA Reg. No. 82972-1-90746), applied by the Bactronizing electrostatic process.
This is treatment, not structural remediation, and it does not fix a leak. If we find water still coming in, you hear it from us before we spray, because new water grows new mold and you would be paying us to treat a surface that is about to get wet again.
The longer versions are on whole-home disinfection and air duct cleaning and treatment.
Do you do air duct cleaning in Summerville?
Yes. Air duct cleaning in Summerville is the same visit as our air duct cleaning and treatment. We clean the registers, the duct work, the coil and the outside of the air handler, then treat those surfaces. It is $50 a vent on the same visit as a whole-home disinfection, or from $399 on its own.
Duct cleaning on its own removes dust and does not replace treatment. The job is set out on air duct cleaning.
Veteran owned, and straight about the price.
Greg Busang owns Bactronix and built it after his military service. He backs every treatment with a 12-month written guarantee on the invoice. If what we treated comes back inside the year, we come back and re-treat it.
If you are selling your Summerville home, the treatment certificate transfers to the buyer and documents something a CL100 letter does not grade. If your home is in Nexton or Cane Bay, see mold treatment in Cane Bay.
Frequently asked questions
Do you treat mold in Old Town Summerville's historic homes?
Yes. We work in the historic homes of Summerville’s Old Town district, many dating to the late 1800s. Whole-home disinfection for mold is a spray taken room by room, so nothing gets cut open and no original finish gets stripped. Where the ductwork is the source, the older sheet-metal trunk lines that hold moisture in their joints get cleaned first and treated after.
Why does my Summerville AC smell musty when it turns on?
The smell is mold in the HVAC system, moving out through the vents. Summerville runs humid roughly six months a year, and that moisture condenses on the cold ductwork and cooling coil and feeds mold there. Cleaning and treating the source goes after it instead of masking it.
Can you treat mold in a new Nexton or Cane Bay build?
Yes. The age of the house does not change the job, the price or the 12-month written guarantee.
How much does mold treatment cost in Summerville?
Whole-home disinfection for mold is $0.30 per heated square foot with a $200 minimum, and it carries a 12-month written guarantee. Air duct cleaning and treatment is $50 a vent on the same visit with no extra minimum, or from $399 on its own. Put the square footage in above, off your county record or your listing, and you see the total before anyone comes out.
Request a window
Put your square footage in above and the price comes back. Pick the day and window that suit you, and we call or write back to lock in the time.