Most people don’t think about their air ducts until something feels off. The house is dusty again two days after you cleaned it. The AC smells a little stale when it kicks on. Someone’s allergies just won’t let up. That’s usually when the question comes up: how often are you supposed to get these things cleaned?
The honest answer is that no single schedule fits every house. Here’s how to figure out what makes sense for yours, especially here in Houston.
What the EPA actually says
The EPA does not recommend cleaning ducts on a routine schedule. Its advice is to clean them when there’s a reason to, and it points to three main ones:
- Visible mold growing inside hard ductwork or other parts of the heating and cooling system
- Rodents or insects living in the ducts
- Ducts so clogged with dust and debris that particles blow out of the vents
You’ll still hear a lot of companies, us included, mention every three to five years as a rule of thumb. Treat that as a reminder to take a look, not a deadline. Some homes need it sooner. Some can go a lot longer.
Why Houston homes often need it sooner
A few things about living here put more load on a duct system than you’d see in a milder climate.
The AC barely gets a break. Cooling season here runs most of the year. Every time the system turns on, it pulls air from the house through the return, and whatever dust gets past the filter starts settling inside the ducts. More run time means more of it.
Humidity. Dust in a dry climate stays loose. Dust in Houston air tends to get damp and stick. In attics, where a lot of ductwork runs, condensation can form on ducts and around vents. If you ever see dark spots that look like mold, the cleaning is only half the job. Whatever is causing the moisture needs to be fixed too, or it’ll come right back.
Storms and water. A roof leak or flooding can soak ductwork and insulation. If water got anywhere near your ducts, have the system looked at before you run it hard again. If you’re dealing with water in the house right now, our water damage restoration page covers what to do first.
Pollen pretty much year-round. Oak and pine in the spring, grasses in summer, ragweed in the fall. Each season leaves its own layer behind.
Constant building. Between new construction and remodels, there’s usually drywall dust or sawdust somewhere nearby. Inside the house, a remodel can dump a surprising amount of fine dust into the return.
Signs your ducts need attention now
- Dust settles back on furniture a day or two after you clean
- Gray, fuzzy buildup on the vent covers or the return grille
- A musty or stale smell when the system starts up
- Droppings, nesting material or insect activity near a vent
- Visible debris puffing out of a register when the air comes on
- You just finished a remodel or moved into a home with an unknown history
One of these on its own might not mean much. Two or three together usually means it’s time.
When you can probably wait
Not every house needs a cleaning right now, and it’s fine to say so. If you change your filter on schedule, you don’t have pets, nobody in the house smokes, there’s been no recent construction, and the ducts look clean when you take a peek, you’re likely in good shape. Check again in a year.
A quick check you can do yourself
- Turn the system off at the thermostat.
- Unscrew one supply vent cover, ideally in a room that gets a lot of use.
- Shine a flashlight into the duct. A light film of dust is normal. Thick, matted dust, debris, droppings or dark spots are not.
- Look at the return grille and the area around the filter. That’s where dirt gets into the system first.
- Snap a few photos so you can compare next time.
Not sure what you’re looking at? Give us a call and describe it. We’ll tell you honestly whether it’s worth scheduling.
Don’t skip the filter
The cheapest way to keep ducts clean is to change the filter on time. Every one to three months works for most homes. If you have pets or the AC is running nonstop in the middle of summer, lean toward the shorter end. A decent pleated filter catches a lot more than the thin fiberglass kind, as long as it fits your system properly.
What to expect if you book a cleaning
A home with one AC system usually takes about one to two hours. Bigger homes or houses with two systems take longer. The exact work depends on the type of system you have, and before we leave we’ll go over what we found. Many people add a dryer vent cleaning on the same visit, since lint buildup is a real fire risk.
Key Cleaning and Restoration Services is family-owned and has been cleaning air ducts since 2002. To set up a visit, call (713) 570-6282 Monday through Friday, 8 AM to 6 PM, or request a quote online. You can also read more about our air duct cleaning service.