Duct Cleaning in South Texas

Most homeowners picture a shop vac jammed into a register. The work is bigger than that. A proper service hooks the system to a high-volume negative-pressure machine on the return side, then runs rotary brushes and air whips through each branch and the main trunks while the vacuum pulls debris back to a sealed collection. Supply registers are blocked off one at a time so airflow concentrates wherever the brush is working. That is how dust actually leaves the duct system instead of moving deeper into it

A typical visit covers the supply trunks and individual branches, the return plenum and return drops (usually the dirtiest part of any system), the blower wheel and motor housing, and the evaporator coil cabinet where dust and condensate meet. We pull and replace the air filter, check the filter rack for bypass gaps, and walk the accessible duct runs in the attic or crawlspace looking for crushed flex, disconnected boots, or torn insulation.

• Negative-pressure source removal across the supply trunks and branches
• Return plenum, return drops, and grille cleaning
• Blower wheel and motor housing cleaning
• Evaporator coil cabinet inspection and cleaning where accessible
• Filter replacement and filter rack seal check
• Visual inspection of accessible ductwork for damage or disconnected boots

Not every house needs duct cleaning on a strict schedule. The reasons that come up most often in our service area are pretty consistent.

• A remodel, drywall sanding, or new flooring stirred up fine debris that ended up in the system
• You just bought a home and the prior maintenance history is unclear
• Visible dust plumes from supply registers when the system first kicks on
• Allergy or respiratory complaints that line up with HVAC runtime
• Pet dander buildup, especially with multiple shedding animals
• Rodent or insect activity inside ductwork — uncommon but real, especially with attic-routed flex duct
• A musty smell at startup, which usually points to coil or plenum biological growth more than duct dust itself

What duct cleaning will not fix is just as important. A system that is undersized, ductwork with major leaks, a clogged filter that has been ignored for a year, or a coil that needs its own cleaning all need their own work. If we open the system and see something other than dust, we will tell you what we see and what it would take to address it. No upsell pressure.

Most homes in this part of Texas run cooling for eight to nine months out of the year. That is an enormous number of operating hours pulling air across filters, through coils, and down ductwork. Add in the fine caliche dust that finds its way through any gap in a return, mountain cedar pollen during the colder months, and the volume of attic-routed flex duct common to homes built since the 1990s, and the picture is consistent. Ducts here collect debris faster than national averages assume.

The pattern is sharper in and around Pleasanton, where most of our work lives. Atascosa County roads kick up a steady supply of fine road dust, ag operations move enough particulate to coat a windshield in an afternoon, and a lot of the housing stock sits on larger lots with longer driveways and attic-routed flex duct on the far end of every supply run. Same story across Floresville, Jourdanton, Poteet, and the smaller communities through Atascosa and Wilson Counties. None of that is a flaw in the home. It just means the ductwork does not stay factory-clean as long as some homeowners expect, and a periodic check is a reasonable part of caring for the system.

A typical job runs three to five hours depending on system size, the number of supply runs, and access. We lay drop cloths near the air handler and at every register we open, then set up the negative-pressure equipment outside or in the garage. After the brushing and vacuum work, we clean the blower compartment, check the coil condition, replace the filter, and walk through what we found before closing the system back up.

If we find duct issues that go beyond cleaning, like flex pinched at a boot, a return plenum drawing attic air, or sections that should be sealed at the joints, we mention them with photos and a clear next step. You decide what to do next.

Ductwork holds a mix of settled dust, skin cells, fabric fibers, pet dander, pollen tracked in on shoes and clothing, and small amounts of mold spores that exist in any indoor environment. When the blower starts, some of that material lifts and circulates. Cleaning the system removes the reservoir, which is the part homeowners actually have control over. It will not, by itself, eliminate seasonal allergens that are entering through doors, windows, and the building envelope. Anyone promising symptom-free living from a single duct cleaning is overselling.

What the work does help with is reducing the load that the filter has to handle, removing surfaces where biological growth can take hold, and giving any add-on air-quality equipment (MERV 11+ filtration, UV-C lamps at the coil, fresh-air dampers) a clean system to work with. People in the home who deal with asthma, dust-mite sensitivity, or post-renovation respiratory irritation tend to notice the difference. People expecting a cure for outdoor pollen will not.

• Removes the dust reservoir already inside the system
• Lowers the burden on filters and whole-house air cleaners
• Eliminates surfaces where biological growth gets a foothold
• Gives IAQ accessories (UV-C, polarized media, ERVs) a clean baseline to work from
• Does not seal a leaky envelope or replace ongoing filtration and humidity control

Most homeowners have never been told what their ductwork is actually made of. It changes the conversation. The three common types in homes around here:

• Flex duct. An inner mylar or polyethylene liner, a wire helix, insulation, and an outer vapor barrier. Cleans well with rotary brushes and air whips, but the inner liner can tear if a tech is rough with it. We size brush heads carefully on flex.
• Sheet metal. Galvanized rigid duct, often found in older San Antonio homes and in commercial buildings. The smooth interior cleans easily and holds up to heavier brushing. Joints and seams are the parts to watch.
• Fiberglass duct board. A pressed fiberglass panel system with a foil exterior. The interior surface is fibrous and porous, which means it holds dust differently and has to be cleaned with softer methods. If duct board has been wet, cleaning is sometimes the wrong answer and replacement is the right one.

A walk-through before the job tells us what we are working with and what method makes sense. We will also note the age and condition of the material. Flex duct that has gone brittle, or duct board with sagging panels, has reached the end of its useful life and is more honestly addressed with replacement than with another cleaning.

The National Air Duct Cleaners Association — the industry's training and certification body — does not recommend a fixed interval. Their guidance is to clean when there is a reason to clean. That is the right answer, and it is the one we give customers.

For a typical South Texas home with a properly sized system, a decent filter changed on time, and no remodeling or pet load, the realistic interval lands somewhere between five and seven years. Homes with shedding pets, smokers, or recurring allergy issues end up closer to three to five. Homes that have just been through a remodel or just changed hands often need it once and then not again for years. Vacation rentals and high-traffic short-term rentals tend to need attention more often because tenants change behavior more than owners do.

Anyone telling you to clean your ducts every year as routine maintenance is selling, not advising.

The Federal Trade Commission has published warnings about deceptive duct cleaning advertising, and there is a reason. The combination of low consumer knowledge and high upsell potential has produced a long list of bad actors. We are not interested in playing that game, and we want customers walking into the conversation with their eyes open.

• The $69 or $99 whole-house special. Real source-removal duct cleaning takes hours and uses thousands of dollars of equipment. The teaser price exists to get a tech in the door. The actual price escalates fast once they are inside, often after presenting scary photos that may or may not be from your system.
• Before-and-after photos that don't match. A common bait-and-switch is showing a generic "before" photo unrelated to the home, then producing a clean "after" of the customer's actual register.
• Mold scares without lab results. A photo of dark buildup on its own is not a mold diagnosis. If a company is telling you you have mold without a swab or lab confirmation, that is a sales tactic.
• Pressure to add chemical sanitization. Sanitizers and biocides have a place, but only after a real cleaning and only when there is a real reason. They are not a substitute for source removal and they are not appropriate as a routine add-on.
• "Blow-and-go" work. A leaf blower into a register is not duct cleaning. If the company is in and out in 45 minutes without negative-pressure equipment set up, they did not do the job.
• No willingness to show the work. A real outfit will open the access panel, show you the blower wheel and coil before and after, and walk through what they found.

Most of the dust that ends up in ductwork got past a filter that was either too restrictive, too cheap, sized wrong, or left in too long. Filters are also the single piece of HVAC equipment a homeowner interacts with directly, and getting them right pays off.

For typical residential systems, a MERV 8 to MERV 11 pleated filter is the practical sweet spot. It catches what most homeowners care about — dust, pollen, larger dander particles — without choking the blower. Going to MERV 13 or higher only makes sense if the duct system, blower, and return-air sizing can support the added static pressure. Many cannot, and a too-restrictive filter starves the system, freezes the coil, and shortens equipment life.

A few things we tell customers regularly:

• Change pleated 1-inch filters every 60 to 90 days, sooner if there are pets or visible loading
• 4-inch and 5-inch media filters typically last 6 to 12 months
• Run the date written on the filter edge, not memory — most "new" filters in problem homes are 6 months old
• Check that the filter rack actually seals; bypass around the filter is the most common reason ducts re-soil quickly
• Avoid the cheapest fiberglass spun filters except in true emergencies — they protect the equipment and almost nothing else

Real biological growth in HVAC systems usually starts in one of three places: the evaporator coil and drain pan, the return plenum, or wet sections of duct insulation. The common factor is moisture. Dust by itself does not become a mold problem. Dust plus standing water, or dust plus a coil that never fully dries between cycles, will.

If we open a system and find growth on the coil or in the plenum, the work goes beyond duct cleaning. The coil has to be cleaned thoroughly, the drain pan and condensate line have to be cleared and treated, and the underlying moisture source has to be addressed. Without that, sanitization is a temporary fix at best. With it, sanitization is appropriate and effective.

What we will not do is recommend chemical fogging across the entire duct system on a generic basis. It does not solve a real problem and it can leave residues that customers later regret. If sanitization is part of the right answer for a specific job, we will explain why, what product we are using, and what the limitations are.

Commercial duct cleaning differs from residential work in scale more than in concept. The same source-removal principles apply: negative-pressure equipment on the return side, methodical brushing of the supply trunks, attention to coil and blower compartments. The differences show up in access, scheduling, and code.

Restaurants with kitchen exhaust systems have NFPA 96 requirements that are separate from comfort-system duct cleaning and usually need a kitchen-exhaust specialist. Office buildings, retail spaces, medical offices, and small light-industrial properties typically need cleaning during off-hours so the work does not affect operations. Multi-tenant buildings often need coordination with property management to access shared mechanical rooms and to schedule access to individual suites.

For business owners and property managers, the goal is usually predictable: clean the system without disrupting the day. We work after hours and on weekends when that is what the property needs.

Three scenarios come up often enough that we will mention them directly:

• Pre-listing. Sellers preparing a home for the market often spend on cosmetic updates and overlook the HVAC system, which is a line item every buyer's inspector looks at. A clean system, fresh filter, and a brief written report on what was done is a small expense that smooths an inspection.
• Post-renovation. Drywall sanding, tile cutting, and refinishing of any kind generates fine particulate that finds its way into return ducts even with the system off. After major renovation work, cleaning the duct system is the difference between months of dust complaints and a fresh start.
• New-to-you homes. When a home changes hands, the new owner has no insight into prior maintenance. A first cleaning establishes a known baseline and gives us a chance to walk the system and flag anything else worth addressing.

Most customers notice a couple of things in the first day or two. The system tends to run quieter because the blower wheel is no longer carrying a layer of caked dust that throws it slightly out of balance. Airflow at the registers feels stronger because the supply side is no longer restricted at the boots and grilles. There is sometimes a brief period where small amounts of fine dust settle on horizontal surfaces near supply registers as the system stabilizes — that usually clears within a week and is normal.

If anything seems off — a register that is now blowing noticeably less air than the others, a new noise from the air handler, water at the air handler base — we want to know. The work includes follow-up. Closing the system back up means leaving it in better condition than we found it, and if something is not right, we come back and address it.

The equipment list is the part most homeowners never think about. It also happens to be the difference between work that holds and work that doesn't.

• Negative-pressure vacuum. Truck-mounted or large portable HEPA, in the 5,000 CFM range or higher. This is what actually pulls debris out of the system. A standard shop vac is two orders of magnitude weaker than what the job needs.
• HEPA-filtered exhaust. What leaves the vacuum has to be filtered to true HEPA so we are not putting fine particulate back into the air around the home.
• Rotary brush system. Variable speed, with brush heads sized to the duct diameter. Soft bristles for flex duct, firmer brushes for sheet metal.
• Air whips and skipper balls. Compressed-air agitation tools used in flex duct where a rotating brush is too aggressive.
• Push-pull cable systems. For longer trunks where the brush needs to be advanced and retrieved cleanly.
• Camera inspection scope. For checking runs we can't see by eye and for showing the customer the actual condition before and after.
• Digital manometer. For static pressure readings, before and after, when the system warrants it.
• Coil cleaning supplies. Foaming cleaner appropriate to the coil material, plus rinse water if the coil pulls out for a real cleaning.

None of this equipment is exotic. It is, however, expensive enough that the operators selling $69 specials don't own it. If a duct cleaning crew shows up with nothing more than a shop vac and a brush kit, the work is not going to deliver what the visit is supposed to deliver.

Static pressure is the resistance the blower has to push against to move air through the system. It is measured in inches of water column (inWC), and a healthy residential system usually runs around 0.5 inWC of total external static, sometimes a little less. The first time most homeowners hear that number is from us, often with bad news attached.

We take static pressure readings before and after a cleaning when the situation calls for it. Two reasons. It confirms whether the cleaning made a measurable difference, and it surfaces problems that a cleaning by itself will not solve. A system reading 0.9 to 1.0 inWC or higher is starving for return-side airflow. The cause is usually undersized returns, a too-restrictive filter, or a closed-off return grille that nobody noticed. We will say so honestly. Cleaning a system that has a return-air problem is a temporary improvement at best.

A clean system with airflow numbers in normal range pulls the right volume of air, dehumidifies properly, runs quieter, and lasts longer. A dirty system with high static pressure does the opposite. Knowing the actual number changes the conversation from a guess to a measurement.

Duct cleaning removes what is inside the ducts. Duct sealing closes leaks so air ends up where it is supposed to. The U.S. Department of Energy estimates that typical residential ductwork loses 20 to 30 percent of its conditioned air to leakage, mostly at boots, joints, and the air handler cabinet. That is a major source of high bills, hot rooms, and dust pulled in from attics through the negative pressure of a leaky return.

If you have rooms that never feel right or a system that runs constantly without keeping up, the answer is more often sealing than cleaning. During a cleaning visit we identify accessible leaks and either address them with mastic and metal foil tape on the spot or recommend a separate appointment when the scope is bigger. Aerosolized sealing methods are also an option for systems where access is limited. Sealing is not a substitute for cleaning. Cleaning is not a substitute for sealing. They solve different problems and the right system has had both done at some point.

Allergy season here is not one season. It is a rolling schedule that lines up with what is blooming and breaking dormancy at different times of the year. Knowing the calendar helps families decide when a duct cleaning will give them the most relief.

• December through February. Mountain cedar, the source of "cedar fever." Pollen counts in this region routinely spike into the tens of thousands of grains per cubic meter. People who live here for years without symptoms sometimes surprise themselves the year cedar finally finds them.
• February through April. Oak pollen, the visible yellow-green dust that ends up on cars and patio furniture.
• May through September. Grass pollens, with overlapping mold spore counts during humid stretches.
• September through November. Ragweed and mountain elm working through the fall.

For families dealing with seasonal symptoms, the practical timing for a cleaning is usually the last few weeks before the season the household reacts to most strongly. Cedar-sensitive families benefit from a fall cleaning. Spring-pollen-sensitive families benefit from a late-winter cleaning. Outdoor pollen will still come in through doors, windows, and the building envelope. What changes is that the duct system is no longer adding to the load from inside.

Customers usually want to know what is in their ducts before they decide to clean them. The honest answer is: a mix that varies a little by household and a lot by maintenance history. The recurring contents:

• Pet hair and dander, often in heavy concentration on the blower wheel where it caked on with humidity
• Construction debris from the original build — drywall dust, sawdust, the occasional screw or offcut
• Children's toys, particularly small Lego pieces, that fell into floor returns and stayed there
• Dryer lint from homes where the dryer exhaust runs near a return path
• Drywall dust from later renovations that never got cleaned up
• Insulation fibers from torn flex duct or compromised attic insulation
• Rodent droppings or nesting material in attic-routed returns, more common in homes near rural acreage
• Insect carcasses, usually from a brief pest problem years prior
• Carpet fiber from supply boots that sit at floor level

None of it is alarming on its own. All of it adds up. The reason to remove it is that the alternative is recirculating it at the rate of several hundred CFM, every time the system runs.

Hardware stores sell brush attachments for shop vacs marketed as duct cleaning kits. The math does not work. A 5-horsepower shop vac pulls roughly 200 CFM at the hose. A real source-removal vacuum pulls 5,000 to 10,000 CFM. The brush has to dislodge debris that the vacuum is strong enough to pull all the way back to the air handler and out of the home. A shop vac drops the debris three feet into the duct and leaves it there, often deeper in the system than where it started.

The work that is reasonable to do yourself: vacuum the visible part of supply registers and return grilles, change your filter on time, wipe the inside of a return grille if you can see dust on it. Beyond that, consumer equipment turns small problems into bigger ones, and the homeowners who eventually call us have usually already tried.

Dryer vents and HVAC ducts share a name and almost nothing else. A dryer vent is a single, dedicated exhaust path from the dryer to the outside. An HVAC duct system is a closed loop circulating conditioned air. Different equipment, different cleaning method, different reason to do it.

The reason to take dryer vents seriously is fire risk. The U.S. Fire Administration attributes thousands of residential structure fires per year to lint accumulation in dryer vent runs. A vent that should run dry and clear instead becomes a long stretch of compressed lint hidden behind drywall. Symptoms are obvious once you know what to watch for. Clothes taking more than one cycle to dry. The dryer cabinet running unusually hot. Visible lint accumulating around the exterior louver. A laundry room that gets warm and humid when the dryer runs.

Many customers who book duct cleaning add dryer vent cleaning to the same appointment. The work is straightforward, the risk it addresses is real, and combining the visits saves a service call. We will mention it during the estimate when the run length, age, or layout suggests it is overdue.

The most marketed claim in the duct cleaning industry is "lower energy bills." The honest version is more measured. A clean blower wheel and a clean coil reduce energy use because the system reaches setpoint faster and runs less. The savings depend on how dirty the system was to begin with and how much else is going on at the equipment side. We will not promise a specific percent.

The wins that show up consistently:

• Shorter cycle times because the system reaches setpoint faster
• Quieter operation because the blower wheel is no longer slightly out of balance
• Better dehumidification because heat transfer at the coil improves when the coil is clean — a meaningful comfort difference in this climate
• Longer equipment life because the motor is not fighting unnecessary drag and the coil is not soaking in a dust paste
• More even temperature delivery, especially in the rooms farthest from the air handler

Duct cleaning is not a substitute for a tune-up, a refrigerant check, or a coil replacement when one is warranted. It is one part of a maintained system, and maintained systems outlast neglected ones consistently enough that it shows up in equipment lifespan averages. That is the real return.

Customers ask what these words mean often enough that it is worth putting them in one place.

Plenum

The large air chamber directly attached to the air handler. There is a supply plenum that conditioned air enters and a return plenum that air enters before passing across the filter and coil.

Trunk

The main rectangular or oval duct that runs from the plenum and feeds the smaller branches.

Branch

The smaller round duct that runs from the trunk to an individual room.

Boot

The metal transition fitting where a branch terminates at a register opening in a floor, ceiling, or wall.

Register

The grille on the supply side, where conditioned air enters the room. Typically has adjustable louvers.

Grille

The covered opening on the return side, where room air re-enters the system.

CFM

Cubic feet per minute. The standard unit for measuring airflow.

MERV

Minimum Efficiency Reporting Value. The standard filter rating scale, running from 1 (almost no filtration) to 16 (true HEPA-adjacent).

Static Pressure

Resistance to airflow inside the duct system, measured in inches of water column (inWC). The single most useful diagnostic for system health that most homeowners have never heard of.

Source Removal

The proper duct cleaning method: agitating debris loose with brushes or air, while a vacuum pulls the dislodged material out of the system entirely. The opposite of "blow and go."

• "Ducts have to be cleaned every year." No. The industry's own training body, NADCA, states the standard as "as needed." Annual cleaning is a sales calendar, not a service schedule.
• "A clean duct system means I can change my filter less often." No. The filter is what keeps the system clean. Skip changes and the duct system re-soils at the same speed it always did.
• "Sanitizing chemicals make duct cleaning more thorough." No. Source removal is the work. Sanitizing chemicals have a narrow appropriate use, mostly tied to confirmed biological growth at the coil or in the plenum, and they get oversold as a routine add-on.
• "Duct cleaning will fix my hot room." Sometimes, if the cause is a buildup-restricted branch or a blocked return. More often the cause is a sizing issue, a leak issue, or an envelope issue. Cleaning the ducts will not fix any of those, and we will say so during the visit if that is what we find.

The evaporator coil sits inside the air handler at the point where conditioned air leaves the system and starts moving down the supply trunk. It is also the wettest, dustiest, most thermally active part of the equipment. Dust that gets past a marginal filter ends up here first, sticks to the wet aluminum fins, and forms a paste that resists airflow and degrades heat transfer. By the time a coil is visibly dirty, the system has been losing capacity and efficiency for a while.

There are two categories of coil cleaning, and the right choice depends on what we find when the access panel comes off.

• In-place cleaning. A foaming cleaner appropriate to the coil material, applied carefully and rinsed either with water or by the condensate the coil generates while operating. Works for coils that are moderately dirty and still accessible from the front face.
• Pull-and-clean. The coil comes out, gets set on a tarp or in a tray, and gets treated as a separate cleaning job. Appropriate for older coils, heavily contaminated coils, and coils with established biological growth where a surface-only treatment will not reach the back side.

A duct cleaning that ignores the coil is incomplete. A coil cleaning that ignores the duct system misses the source of the contamination. Doing both at the same visit, with the same setup already in place, is what gives the system a real reset.

There is a point at which cleaning a duct system stops being the right call. We will say so when that is what we see, even when it is not the answer that generates the bigger invoice today. The recurring situations:

• Flex duct that has gone brittle, is sagging at the boots, or is pulling apart at the connections. Replacement is more honest than cleaning a system that is failing.
• Fiberglass duct board that is delaminating or has been wet. Cleaning fibrous material that is breaking down releases more contamination than it removes.
• An air handler that is older than the ducts, struggling on every cycle, and short-listed for replacement anyway. Cleaning the ducts of a system about to be torn out is a wasted visit.
• A whole system installed fifteen to twenty years ago that has never been seriously updated. At that point, planned replacement is usually a better return than another cleaning and another year of patching.
• Ductwork sized wrong for the equipment, with chronic high static pressure that cleaning will not change. The right answer is a redesign, not another vacuum visit.

Clean ducts on a system that needs to come out anyway is the duct cleaning equivalent of detailing a totaled car. We would rather have the harder conversation up front than send the customer the wrong invoice.

A few situations need a different approach, and homeowners typically do not know that until they need to.

• Kitchen fire residue. Even a small grease fire deposits soot and combustion byproducts inside the return path of the HVAC system. The smell fades and returns in cycles for months until the source is actually removed. Restoration-grade cleaning combines source removal with sealants on porous surfaces and replacement of any duct insulation that absorbed odor.
• Heavy smoking household. Decades of nicotine deposits build on every interior surface of the duct system, and standard cleaning will not fully remove the odor. The honest conversation is whether to clean to a restoration standard or replace affected sections of duct outright.
• Construction or remodeling done with the HVAC running. When the system was operating during heavy drywall work or floor sanding, the dust loading is heavier than residential cleaning is normally sized for and may need an additional pass to fully clear.
• Pet odor in flex duct. Severe cases involve odor that has soaked into the inner liner. Cleaning helps. Replacement of the affected runs is sometimes the more honest answer.

We can handle each of these. The approach is different from routine cleaning, the time on site is longer, and the conversation up front has to be honest about what cleaning will and will not solve. Customers in restoration situations are usually working with insurance or a public adjuster, and we are happy to coordinate documentation and photos for the claim.

Indoor humidity matters more than most homeowners realize. The comfort sweet spot is roughly 40 to 50 percent relative humidity. The local outdoor average usually runs higher. The HVAC system bridges the difference by pulling moisture out at the evaporator coil and draining it away through the condensate line.

A dirty system fails this job in specific ways. The coil cannot transfer heat efficiently, so it pulls less moisture. The drain pan accumulates dust that holds water instead of letting it drain. Unsealed duct leaks pull humid attic air into the supply during cooling cycles, undoing part of the dehumidification work the coil just performed. The result is a system that runs longer to hit a cooler thermostat reading without ever actually drying out the house.

The signs of a system losing the humidity fight are common in this region.

• A home that feels cool but clammy, with the thermostat showing the right number
• Wood floors and trim showing seasonal movement and small gaps
• Persistent musty smells when the system first kicks on after sitting
• Window condensation in the cool months, especially on north-facing glass
• Mildew showing up in closets, under sinks, and around exterior wall outlets

None of these are caused by duct dirt alone. Cleaning the system is one of the levers that gets indoor humidity back into the comfort range, alongside coil condition, refrigerant charge, and proper sizing.

The IAQ accessory market is full of products. Some work well. Some are mediocre. Some are oversold and a few are actively counterproductive. The honest run-down:

• MERV 11 to 13 media filtration. Works well, provided the duct system can support the added static pressure. The most reliable upgrade most homes can make.
• UV-C lamps at the coil. Effective against biological growth on the wet surfaces of the coil and drain pan. Targeted and useful, not a magic light. Bulbs need replacement on the manufacturer schedule or the work stops.
• Polarized media filtration. Effective in the right install. Requires a power supply and captures fine particles that a standard pleated filter misses.
• Energy recovery ventilators. Bring controlled outdoor air in while exchanging heat and moisture between the incoming and outgoing streams. Useful for tight homes and tight commercial spaces. Older leaky homes may not need them.
• Whole-house dehumidifiers. Useful in homes where the HVAC system alone cannot keep humidity in range, often because the equipment was sized aggressively for cooling at the cost of runtime.
• Ionizing air purifiers. Mixed-to-weak evidence. Some produce ozone as a byproduct, which is a respiratory irritant. We do not install or recommend the ones that do.
• Ozone-generating "air purifiers." Avoid. The EPA has been clear on this category for many years.

We will not pressure any of these on the same visit as a duct cleaning. If accessories come up in conversation, it is because the situation made the case, not because there was a quota to hit.

You don't need to know everything before calling. Whatever you do know shortens the conversation and helps us match the right crew, the right truck, and the right amount of time to the property.

• The age of the home and the HVAC system, if known
• Approximate square footage
• Number of HVAC systems — some homes have one, some have two, occasionally three for large properties
• An approximate count of supply registers and return grilles
• Where the air handler is located: attic, garage, closet, mechanical room
• Whether the home has had duct cleaning before, and roughly when
• The specific reason you are calling: a remodel, a new pet, allergy concerns, a recent home purchase, a musty smell at startup
• Access notes: alarm codes, gate codes, dogs in the yard, restricted hours
• Any household members with respiratory sensitivity so we plan dust containment with extra care

Anything missing from that list, we will ask. The point is to come prepared, finish in one visit, and leave the system in measurably better shape than we found it.

The cleaning is the reset. Keeping the system clean is the part the homeowner controls. A few habits make a meaningful difference:

• Change the filter on schedule and write the install date on the filter edge in marker
• Vacuum supply registers and return grilles every couple of months, surface only
• Keep return grilles unobstructed — no furniture pushed against them, no rugs covering floor returns, no curtains hanging over wall returns
• Avoid running the system continuously on "fan on" mode if you are getting humidity complaints; auto cycles let the coil drain between runs
• Schedule a standard HVAC tune-up once a year, ideally in spring before the heavy cooling season starts
• Address visible water leaks at the air handler base immediately; a slow drip across the housing is the start of biological growth, not a cosmetic issue
• Note any new sounds at startup or shutdown and call early — small problems catch easier than large ones
• Watch for dust accumulation reappearing on horizontal surfaces near supply registers within weeks of cleaning; it usually points to a filter rack that is not sealing or to a return-side leak

None of this is complicated. Done consistently, it is the difference between cleaning the duct system every five to seven years and cleaning it every two.

Duct cleaning gets handled differently when there is more than one party with a stake in the property. The recurring scenarios:

• Long-term rentals. The landlord pays for HVAC maintenance, and most lease agreements specify exactly that. Duct cleaning is rarely covered as routine maintenance, but it is a reasonable request when symptoms point to it. We coordinate with both the property owner and the tenant on scheduling and access.
• Short-term rentals and vacation rentals. Turnover-driven properties typically need cleaner air quality than the average owner-occupied home. Property managers running multiple units often schedule cleanings on a rolling basis, two or three units per visit, to spread the work and keep occupancy high.
• Multi-family buildings. Apartment complexes and townhouse communities sometimes share return paths, and the cleaning approach has to account for the building's overall HVAC design. We coordinate with on-site maintenance staff and schedule around occupant access.
• Commercial property management. Office buildings, retail strips, and mixed-use properties usually need work scheduled outside of business hours, with documentation suitable for tenant communication and lease records. We send a written summary of work performed for every commercial visit.

In every case, the goal stays the same: clean systems, minimal disruption, honest reporting back to whoever is paying for the work.

For a single-system home in Pleasanton, the surrounding Atascosa County communities, or anywhere across the broader San Antonio market, real source-removal duct cleaning usually runs $450 to $900. That figure includes the blower wheel and an in-place coil cleaning. Two-system homes typically land between $750 and $1,400. Anything under about $300 is a teaser — the price climbs once a tech is inside. Anything past $1,200 should come itemized; coil pulls, sanitization, and duct sealing belong on their own lines, not folded into one round number.

What actually moves the price between two honest quotes:

• Number of supply registers and return grilles — each opening is time spent masking, brushing, and re-sealing
• Where the air handler lives. A standing-height attic is straightforward. A 30-inch crawl attic in August is not.
• Coil condition, and whether it can be cleaned in place or has to come out for a proper job
• Blower wheel buildup. A caked wheel usually means pulling the assembly for a separate cleaning.
• How far the negative-pressure hose has to run to reach a window or exterior door
• Optional add-ons that belong itemized: dryer vent cleaning, duct sealing, sanitization where it is actually warranted, filter rack rework

Written estimates come after a walk-through. A final number quoted blind over the phone is either padded for worst case or going to be rewritten once the tech sees the system.

Our shop is on Coughran Road in Pleasanton, and most of our day-to-day work runs out from there: Pleasanton itself, the rural acreage along the 281 and 97 corridors, Floresville, Jourdanton, Poteet, Charlotte, Lytle, Somerset, and the smaller communities across Atascosa and Wilson Counties. From the same yard we cover San Antonio and the suburban belt — Alamo Heights, Terrell Hills, Olmos Park, Boerne, New Braunfels, Schertz, Cibolo, Converse, Universal City, Live Oak, Kirby, Leon Valley, Helotes, and Castroville.

The work changes by area. Around Pleasanton and through Atascosa County, most homes are single-story builds on larger lots, with attic-routed flex duct stretching to rooms that sit a long way from the air handler. Long runs in unconditioned attics, plus dust kicked up off county roads and ag fields, are why ducts here load faster than what national averages assume. Floresville and Jourdanton look much the same — flex duct, longer runs, and rural-road dust working in through any return-side leak. Inner-loop San Antonio runs the other way: older sheet-metal trunks in tight crawlspaces, where access eats the day even though the metal itself cleans up well. Subdivisions built from the late 1990s onward in Stone Oak, Alamo Ranch, and the Cibolo and Schertz corridor are flex-duct territory again, with the same heat-aging and rodent issues we see further south.

Knowing what to expect before we pull in saves time on both sides. The right truck shows up with the right brush sizes, enough hose, and a realistic window for the visit.

Most homeowners never read the standards the trade is supposed to follow, and there is no good reason they should — they are written for technicians and inspectors. But knowing what is in them keeps a sales pitch from passing as expert advice.

• NADCA ACR. The trade-association standard for assessing, cleaning, and restoring HVAC systems. Defines what a cleaning actually covers, what equipment it requires, and when sanitization belongs in the conversation. Reputable shops work from it whether they cite it at customers or not.
• ASHRAE 62.1. Ventilation for acceptable indoor air quality. It does not put duct cleaning on a schedule; it sets the filtration and outdoor-air baseline that determines how fast a system gets dirty to begin with.
• EPA, "Should You Have the Air Ducts in Your Home Cleaned?" The agency's plain-English consumer guide. Recommends cleaning when there is a reason for it, not on a calendar. Worth ten minutes before you book anyone.
• FTC consumer alerts on duct cleaning. Published because of how regularly this trade has generated bait-and-switch complaints. The advisories cover teaser pricing, scary-photo upsells, and the usual tactics.

If a company is unwilling to point you at any of these, that is information too.

A lot of duct systems get dirty because the filter rack leaks, the return is undersized, or the coil has been pulling moisture across a layer of dust for a few seasons. We usually recommend looking at the filter rack seal, the coil condition, return airflow, and at least a basic static pressure reading across the air handler. Those checks take a few extra minutes and tell us whether the cleaning is going to hold or whether the system will re-soil itself within a season.

When it makes sense, customers pair duct cleaning with furnace repair or an AC tune-up. Doing the work together saves a service call and gives the equipment a true reset rather than a partial one.

When should a duct system be inspected or cleaned?

It makes sense to have the duct system looked at when certain rooms are hard to keep comfortable, airflow feels weak, dust keeps building up quickly, or the system seems to be working harder than it should.

Can duct problems affect heating and cooling performance?

Yes. Poor airflow, leaks, and buildup inside the duct system can make the HVAC equipment work harder and can lead to uneven temperatures from one part of the property to another.

Do you help with both duct cleaning and airflow corrections?

Yes. If the issue involves buildup, leaks, poor airflow, or a system that is not distributing air evenly, we help identify what is causing the comfort problem and what should be improved.

Whether you already know you need duct cleaning or you are still comparing your options, Miller Cooling & Heating can help you understand the problem and choose the next step with confidence.