Air Tech: Air duct, dryer vent cleaning and HVAC sanitation. Air duct and dryer vent cleaning for Maryland, Virginia and Washington DCCommercial & Residential Air Duct, HVAC Cleaning Service MD/VA/DC

All about air duct & HVAC cleaning: Air duct cleaning facts, air duct cleaning myths + tips & tricks to pick or kick HVAC cleaning firms. 240-388-0030  Air duct cleaning | Dryer vent cleaning | References | Home

Because HVAC cleaning is not yet fully regulated, most people are unfamiliar with the processes involved, and less prepared to distinguish a reliable service provider. Thus, many companies take advantage by up-selling supposedly integral tasks; operate illegally, use sub-standard equipment or untrained subcontractors, or worse; cut corners in cleaning procedures to book more jobs per day. According to the BBB, these "blow-n-go" companies (as they have come to be known) are often attractive to unwary consumers because of enticing low prices, but generally create more problems than what they solve. In addition to professional uncertainty, widespread issues are:

  1. Bait & Switch tactics, or SCAMS. Video Reference 1 | Video Reference 2
  2. Poor Craftsmanship, or NEGLIGENCE.

So when all claim to be the best, and no one knows who's who until is too late, Air Tech comes forward in good faith. We're a local enterprise, so before a client, you are (to us) a valued neighbor, and with it comes all due respect. Let us then address these gray areas of the trade, explain how things must be done, help you make an informed decision and; should you wish to go ahead, how to prepare your home & what to expect, so nobody gets hurt.

What is air duct cleaning, really?

HVAC cleaning dc/md/vaThe term "air duct cleaning" generally refers to the work performed by companies that clean HVAC systems, which is a misnomer because it implies that only ductwork is cleaned. The term "Heating, Ventilation & Air Conditioning (HVAC) system cleaning defines best what Air Tech does, which is the comprehensive cleaning of all existing components of a forced air system.

What's the difference?

We also clean HVAC units, and like No one else does. Because these deliver 3 functions (heating, ventilation & air-conditioning) to provide thermal comfort & acceptable indoor air quality, even manufacturers recognize the importance of this task. Also, EPA clearly states: "It makes nonsense to clean ductwork if air handlers are left untouched. Air ducts deliver exactly what an air handler drives, and if the ductwork is dirty, so are the air handler's guts".

How do I find out if my HVAC unit actually needs cleaning?

furnace 2furnace.bmp (52678 bytes)All air handlers -or HVAC units- are accessible for inspection by design, so power off the unit first, and then remove its front cover panels to take a look. A GAS furnace is depicted to the left. Note the blower fan at the bottom and; the air filter enclosure to the side. By removing the air filter, part of the return ductwork will also become exposed. Since the blower fan is the heart of your system, it should be inspected first. If you see anything like in the pictures below, then consider having the HVAC unit cleaned along with the air ducts.

Left side pictures denote excessive dust & debris, which tells you there's a problem with the air filter. The ones to the right denote excessive rust, which means there's a moisture problem that needs immediate attention.rusty blowerdirty and rusty blowerdusty blowerdirty blower




Keep in mind that when the system is on, what's in the blower is also in the air that you breathe, so be the judge. Also, of note is that if the blower fan is dirty, so is the rest of the system, and blower fans cannot be cleaned while in place. They MUST be removed & cleaned outdoors, and this task alone takes 1 hour or so.

Evaporator CoilYour evaporator, or A/C cooling coil looks like an automobile's radiator and it usually sits above the furnace. You should know that dirt & water socialize in there, and yet is the most neglected of all HVAC parts. That's because periodic servicing takes soft hands & a fair amount of patience, and for many HVAC maintenance contractors ..patience is not worth a dime. Inspecting A/C coils in gas furnaces can be tricky but again, if the blower fan is dirty, so is the coil's inner side.heat pump

Heat pumps are far more accessible. When you remove the cover panel the blower fan is totally exposed, and also most of this infamous coil, which unlike that of a gas furnace, it actually faces the incoming airflow. Thus, it is prone by design not only to do its own, but also the air filter's job. So-please, pay special attention to it.dirty and rusty cooling coil

dirty cooling coilIf it looks like in the pictures to the sides, have it cleaned ASAP. Moistened dirt build-up on its surfaces work pretty much like a hair clog in your sink. It can restrict airflow up to a point in which ice build-up may occur, blower fans choke, fan motors overheat or burn, or may cause blower surfaces & surrounding areas to get filled with mold. If that may be the case, you'll find out at first sight.

Cleaning coils & blower fans are tedious tasks, take specialty tools, character, know-how & patience to do it right; or even licensing, depending on where you are. And this is what "blow-n-goers" Feast off, Cheat on, or Skip at all.

Consumer's Countermeasures: Seeing for yourself the condition of your HVAC unit Before you call anyone; knowing what needs to be cleaned and; saying that you want -and will- closely inspect these key HVAC parts along with the ductwork at the time of booking may cause certain companies to suddenly experience booked up syndrome, or please hold attacks. Have some coupons? Go ahead now - Try One Out! :)

Should Licensed Contractors offer options?

If regulations apply, then the answer is no. According to the EPA, if an HVAC system is to be cleaned, is everything from top to bottom, no piece should be left behind; but sure enough, there are circumstances in which a licensed contractor might choose to accommodate your personal needs at a reasonable price, but not without making sure that you understand that while performing a limited task, cannot assume liability for anything else. If no regulations apply and; should you agree to the facts in advance, then you may choose from two half-way options:

  • Air Duct Cleaning - Meaning, all of the ductwork, vents & grilles, but nothing else than what distributes airflow.
  • Air Handler or HVAC Cleaning - Meaning, all of the heating & cooling machinery, but none of the ductwork.

But until your local authorities draw the line & set apart a custom service from a half ... job, anything less than a full-service is not worth the try. Regulations or not, EPA still makes sense, and we stand by the authorities 100%.

Are there any health benefits that come from HVAC cleaning?

air duct cleaning md/va/dcNone that we, as contractors, are legally allowed to discuss, advertise, or assume any credit for. If you "catch" anyone making health claims, not only scratch it off the list, but also report it to the EPA or BBB at once. However, it is well known that dirty air ducts offer undisturbed shelter, numerous food sources and therefore, a near perfect breeding environment for fungi, bacteria and viruses. If simple tasks like washing your hands, bagging your trash or wiping your kitchen counter can, in fact, prevent about 4 diseases, imagine what cleaning your air conveyance system might add to the list!

Does air duct cleaning eliminate dust, pollen or mold?

Never did, never will, and we're glad to tackle this myth - Mold spores and pollen are a part of the natural environment at all times, and we (humans) are for the most part the source of indoor dust. Any duct cleaner that use such an extreme word cannot be trusted. What air duct cleaning does is remove EXCESS accumulation of that stuff. By doing so, it minimizes the widespread of it as the HVAC system operates, and thus improve the indoor environment to a certain degree. But it won't stop wind from blowing, trees from growing, or you from shedding skin.

Can air duct cleaning alone reduce home energy bills?

HVAC cleaning md/dc/vaVery little, if at all. That is, of course, under normal circumstances. Popular exceptions include liner insulation detachment (well known for blocking dampers), small objects (pet/children toys, cans or even tennis balls) that have fallen through floor mounted vents (could block a supply branch), or when excessive buildup begins to detach, causing frequent clogs on the air filter, which chokes the system's airflow.

Otherwise, the key to optimal HVAC performance lays in the air handling (or HVAC) unit itself. Research has clearly shown that removing airflow-restricting debris from sensitive HVAC components such as cooling coils & blower fans does, in fact, bring the system's energy efficiency back to near factory specs.

Why are there so many advertisement consumer warnings?

air duct cleaning crookIn fact, nearly 60% of service providers only clean air ducts, and most for $400 or less. Problem is that air duct cleaning alone is a limited task, and the act of bringing up health issues while implying the benefits of the comprehensive scope of work to promote the service is misleading, or deceitful. Many offer fog sanitation, edge sealants, UV lights, electronic air filters or other "miracle" products to cover their tracks, but if you look closely at the facts, all that they do is just clean air ducts, sell toys & add-ons.

Should I have my air ducts sanitized?

Although it sounds like it makes sense, biocide fog sanitation is NOT a "routine" procedure. It is not uncommon for fungus or bacteria to be present in dirty ductwork, and it can all be removed using the appropriate equipment. Also, biocides application is limited to non-porous materials only; cannot be applied to liner insulated and/or fiberboard ducts. If in despite the facts you choose to have your ductwork sanitized, make sure to obtain a copy of the biocide's MSDS. We use MDF-500 to sanitize air handlers - but you better give us a darn good reason to spray it in ductwork.

How should air ducts be cleaned?

inside-a-ductThe safest & most effective way to clean air ducts is to employ controlled source removal methods of cleaning, as defined by NADCA Standards. Large or industrial systems allow contractors to enter and crawl -or even walk- inside the system's main trunks and key parts, for which various source removal techniques may apply; Not-So On Smaller Systems.

Air Tech's Professional Air Duct Cleaning SystemLight commercial & residential ductwork must be cleaned following a procedure called the Push/Pull Method. Meaning, the contractor shall place the entire system under negative pressure through the use of a powerful Big-Mouthed Vacuum Machine. While the vacuum massively draws air backwards, agitation devices are inserted into all branches & main trunks to dislodge & sweep all debris towards it, and eventually out of the system. All authorities agree, vacuum power is everything.

NADCA compliant equipment can be distinguished by its vacuum's impressive SIZE, airflow, multi-stage HEPA filter banks & various independent agitation devices.

But big or small, red or blue, equipment does not clean air ducts - People do. And if air ducts remain dirty, it is not the equipment's fault. Here lays the tremendous importance of INSPECTING the contractor's work at the time of service. If the contractor cannot demonstrate its performance upon request at such critical time, then you may refuse to pay the contractor until you verify the quality of its work.

How often should residential HVAC systems be cleaned?

EPA recommends that you should consider this task not on periodic, but on "as needed" basis, and we certainly agree. Frequency of cleaning may depend on several factors, one of which is preference of the homeowner. Some factors of influence while considering more frequent cleanings are:

  • Smokers, intensive cooking, high occupancy/traffic or child care activities in the household
  • Pets that shed lots of dander, highway or homebuilding projects nearby, etc.

But rest assured, nothing will make your system last longer & cleaner than a good quality, pleated, properly sized, carefully installed air filter. What's The Trick? Make sure there is no airflow by-pass around the air filter framing.

What criteria should I use in selecting a Residential HVAC cleaning contractor?

  • Make sure the company is Legally Established and listed with your local Better Business Bureau.
  • Verify that the company cleans key HVAC parts such as A/C coils & blower fans, ask how they do that.
  • Ask how the company will show you all improvements, and if there's a fee for it. (avoid will-mail DVD's)
  • Find out what's the contractor's policy regarding accidental equipment damage during the cleaning process.
  • Ask how many technicians will be on site to perform the work. True HVAC cleaning is not a one-man job.
  • Get a list of references, make sure to call those nearest to you, check with neighbors for a word of mouth.

What criteria should I use in REJECTING a contractor upon arrival?

  • When you see an un-marked truck, or a van with magnetic signs. Is it actually them, or just a "sub"?
  • If the duct cleaning equipment looks like it fits in the trunk of a car (please read BBB report #3)
  • If it tries to bring any heavy equipment inside before inspecting & testing your HVAC system.
  • If it tries to up-sell any task or option that you didn't discuss or asked about at the time of booking
  • If it recommends any HVAC upgrades or costly repairs right off the bat, before even testing the system
  • When tardiness or sudden scheduling issues arise after appointment time has passed. That's GROSS.
  • If it fails to produce any air duct inspection tools upon request (bore scope, video probe, camera, etc.)
  • When technicians don't look properly dressed for the job, or seem too "casual" for business hours.
  • If the cleaning equipment looks dirtier than your ducts. Keep in mind, you have the right to inspect it!
  • When it talks about mold-related health issues while inspecting the furnace. (a scare tactic for else)
  • When it says that the house - or the system - is bigger than expected. Big red flag. Send it HOME!

How long should it take to clean a typical residential air conveyance system?

air duct cleaning timerWhen done by the book, it takes from 3 to 7 hours per system, depending on system's age, location, size & duct-work configuration. That is, of course, under ideal conditions. This means (1) Fairly good access to all systems components; (2) Uninterrupted worker's pace, (3) Enough power to operate all equipment and most important; (4) A friendly & respectful environment under the circumstances. Learn more


Air duct cleaning is done by appointment only, and for very good reasons. Although IT IS NOT a "messy" process, it involves a series of disruptive tasks that may interfere with traditional business or daily life, and thus cause a myriad of upsetting situations if the site -or occupants- are not prepared for it. Let's start with:

Intrusive Traffic - In order to clean an HVAC system, a service area reconnaissance or walkthrough must be performed first, and permission will be asked for at the time. If allowed to, crew then considers full access to all HVAC service areas granted and "project started" from that point on. Personal activities (showers, breast-feeding or else) should be avoided to prevent embarrassing situations until project completion.

Utilities Shut-Down - (1) Your HVAC system will be turned off, which may cause significant changes to your indoor environment; (2) Accessories hard wired to other electrical branches must also be powered down. (3) To remove humidifiers, crew may have to cut water supply and; (4) To clean heat exchangers, gas lines may be closed too. We all have a life to live and yes, dinner must be cooked - so unless you wish to inspect their work, it would be in your best interest not to distract, interfere with, or halt the crew.

Noise - An industrial strength vacuum machine hooked to your home's duct-work, an air compressor near your doorsteps and 2 guys hauling 35 Ft. long rotary brush snakes throughout every room's vents will not go unnoticed. Naps, conference calls, book or song writing -or perhaps meditation- would certainly be out of the equation.

Tampering with personal items to access grilles or hidden vents is often inevitable, and you should expect such occurrence. Accidents happen, but most can be avoided - In this case, it is your duty to secure lose or valuable items in narrow hallways & near HVAC vents to minimize the odds. Key items include delicate ornaments, antique furniture, toys, clothing, power cords & electronics within a 4 Ft. radius from a vent. Keep in mind, crews are there to perform a specific task, and although moving aside a few items may be OK with them, it is technically outside their scope of work. Thus, cannot be held responsible if anything brakes, gets misplaced or not moved back at all.

Heavy Moving & Lifting - Ceiling-mounted vents are often a challenge because heavy furniture (beds, sofas, pianos, etc.) underneath may need to be temporarily removed to make room for ladders. Also, wall & floor vents may be obstructed by heavy desks, bookshelves or entertainment centers. If this may be your case, please take the appropriate measures in advance, or make sure to discuss heavy furniture lifting at the time of booking. A dedicated moving crew may be more expensive, yet may save you a week's worth of backaches.

Liability Exclusions

Paint & Drywall Chipping - Water based paint does not adhere to metal as good as it does to drywall and; some vents are glued to drywall for whatever reason. In despite of how careful crews may be, it is possible that; if supply vents or return grilles are glued or painted over, minor damage may occur upon their forced removal. Because vents & grilles cannot be glued or water-based painted by code, neither crew or company can assume liability.

Concealed Wiring Damage - Many contractors discretely run thermostats, phone, cable or satellite video, alarms, and even audio wiring through the inside of older home's ductwork, which is against building codes. And yes, this may go undetected for many years, and further concealed by heavy debris accumulation, which often makes it undetectable to inspection scopes or cameras. So unless the duct cleaning contractor is notified in advance, cannot assume liability and/or be held responsible for accidental inner-ductwork wiring damage.

Additional Considerations

  • Hovering - Air Tech's crews will proudly show you what's being done. Just don't get too close to them while they're doing it. In addition to annoying, toe-stepping & head-bumping can be painful.
  • Shoes - OSHA rules, and under no circumstances HVAC workers are to take off their shoes. High amperage equipment, hidden power lines and metal duct-work are a constant risk for worker's electrocution and; rotary and/or compressed-air agitators can generate harmful electrostatic discharges. We will however, wear cloth booties to protect white or religious use carpeting, and use drop clothes to lay our tools over brand new flooring. But-please, don't ask the crew to wear booties on stairways, hardwood, ceramic or vinyl floors; it's a Slip & Fall waiting to happen, it is against OSHA regulations, and if you look at it in perspective, it's not worth forcing circumstances - it makes you responsible for injuries or damage! Safety First, God Bless OSHA.
  • HVAC Compartment Stuffing - Our biggest, heaviest & most powerful tool (negative air machine) will have to be placed at two different points next to your HVAC unit, and crew needs to focus on what they do best. A little space around the air handler will allow technicians to work at a much faster pace - So spend 10 minutes, clear some clutter, Save 2 Hours Off Your Day!

Finally, keep in mind that every home or building is unique in many ways, and so will be your air conveyance cleaning project. In despite the odds, our crews grow wiser and more observant with every job, and are always prepared to back-track in a second, should human factors or special needs may arise. Hoping we may have the opportunity to serve you soon, we'll be delighted to answer any other questions or be of assistance in any other way. Keep in mind, we're just a phone call away! 240-388-0030

Home | About Air Tech | Back To Business | Check Our References