The Ultimate Guide On How Often to Clean Your Air Ducts

“All of our articles regarding air duct cleaning are written by experienced professionals that have over two decades of experience in the industry. Our articles are not written by bloggers whose only goal is clicks and profit.”

A technician cleaning air ducts in a ceiling.

If you ask a professional or search online about how often you should get your air ducts cleaned, you will be surprised by how inconsistent the answer will be. You will find that the answer varies from one duct cleaning professional to the next. The most common answer you will get is to have your ductwork cleaned every 3-5 years, but this may not be true for most homeowners.

The reason behind the inconsistent answers is because each home and living situation is unique. When you read online that you should have your ductwork cleaned every 3-5 years, then you need to understand this is more of a guideline and not a definitive answer. 

This guide will help you determine the frequency in which you should have your air ducts cleaned after you consider all the factors.

Factors to Determine How Often to Have Your Air Ducts Cleaned

The frequency in which you have your home’s air ducts cleaned depends on several factors such as: your living conditions, year the home was built, health of your family members, and the condition of your ductwork. An honest air duct cleaning company will help you determine an appropriate timeframe to clean your ductwork by taking all these factors into consideration.

Old ranch house

Age of Your Home

The age of your home will have an impact on how much dust and dirt accumulates in your ductwork. The older your home is, the more likely it may need to be cleaned more often because the ductwork may leak air, the ductwork layout may not be up to modern HVAC codes, location of vent registers are in high traffic areas, the placement of your furnace and older homes tend to be less air tight as they age.

Newer homes are built with up to date building codes which helps keep dust, debris and other allergens from entering your closed HVAC system. A home built in the last 10-15 years typically does not collect as much dust mainly because they are more air tight and have better filtration systems. That is not to say that you do not need an air duct cleaning but you will not need them as often as older homes do.

Design of Your Home

The design of your home can dictate how often you need your ducts cleaned. Smaller homes tend to accumulate more dust than larger homes because they have less return air ducts. The return air ducts are responsible for pulling in old air in the home and recycling it through the HVAC system to provide you with fresh clean air. 

The return air ducts not only recycle old air but also help suck in dust and debris floating around your house. When your home does not have enough return vents, then dust will settle more often around the home and more often in your return vents. This results in a more frequent cleaning of your heating and cooling system.

Style Of Your Home

Ranch style homes or 1 story homes collect more dust in the HVAC system mainly because the main trunk lines run through the center of the home. This isn’t a bad thing but they will accumulate dust and debris more quickly because the return vents are typically a few feet from the main trunks that run to your furnace. Main trunks are those large sheet metal rectangle box like structures that are attached to your furnace and screwed to your ceiling joists.

The shorter the ducting runs to and from your furnace, the more CFM (cubic feet per minute) your furnace is putting out. CFM is a measurement of the volume of air flow that is moved or exchanged each minute from your furnace fan motor. CFM is strongest in ranch style homes because the ducting is closer to the furnace, which results in stronger return air flow. 

You may notice airflow is stronger in the vents that are closest to your furnace and weaker air flow as you get further away from the furnace. This is why a lot of 2 story homes have heating and cooling issues on the second floor in case you were ever wondering! More air flow means less dust being collected in your HVAC system.

floor vent covers wood

Location of Vent Registers

The location of the vent openings or vent registers in your home can contribute to how often you clean your air ducts. If your vent registers are in high foot traffic areas or if you have floor vent registers then those are going to attract more dust and debris than ones built into the walls. 

Supply and return venting that is located in high traffic areas are dirtier because homeowners and pets are constantly walking by them and stirring up dust. When the dust is repeatedly disturbed then it has to settle somewhere. Overtime, the dust and debris finds its way into your supply and return air ducts. 

Ducting that is built into the flooring typically turns into a garbage can for dust, debris, pet food and children’s toys. Objects and dust tend to fall into these openings due to gravity. They collect a lot more debris than vents installed into the walls. There isn’t much you can do to prevent these from getting dirty but regularly sticking your shop vac hose down them will help keep your HVAC system cleaner and avoid the need to get your air ducts professionally cleaned more often.

Design of Your Ductwork

The design of your ductwork in your home can have an effect on how often you clean your air ducts because of the different layouts and materials used. The main cause of dirty air ducts is the result of poorly designed ductwork that doesn’t move airflow properly. Another factor could be that your HVAC company cut costs and installed an underpowered furnace that doesn’t have enough CFM to move airflow throughout their design.

Dust is intended to be cycled through the return system so your furnace filter catches it. Therefore, having a lot of twists and turns in your sheet metal ducting will cause build up to occur in these sections. When your ducting is too long or has a lot of turns, then airflow is restricted and CFM is minimized causing poor indoor air quality and excessive amounts of dust and debris to pile up.

Rusted Ductwork from condensation.


Condition of Ductwork

The condition of your ductwork will have an impact on how often you clean your air ducts. Overtime sheet metal ducting and flex pipe ducting will deteriorate with age. There are three types of ducting material used in the design of your ductwork. 

The three materials often used are sheet metal, fiber board, and flex ducting. These materials all have a long term effect on the frequency in which you need your vents cleaned.

Sheet Metal Ducting

Sheet metal ducting tends to be the best material to use and often needs cleaning a lot less than its counterparts. When sheet metal ducting starts to fail it is usually because of rust build up from having a bypass humidifier installed. The humidity inside your ducting starts to rise and collect on the walls of the sheet metal. Therefore, the condensation will start to rust the sheet metal over time and cracks and holes will form.

This will cause CFM to drop in your HVAC system and the airflow will become weaker over time. With less airflow moving through your system, dust and debris will start to accumulate at a faster rate.

Flexible Ducting

Flexible ducting is often used in homes that do not have a basement or in the construction of additions added onto homes. You can identify if you have flex ducting by visually inspecting it. Flex ducting looks like a slinky wrapped in aluminum foil or plastic. 

Flex ducting traps a lot of dust and debris because of all the ridges. It is not smooth so it tends to catch debris much easier when it is pulled into the HVAC system. Flexible ducting will also be more susceptible to dry rotting and being chewed up by pests because of the material used. Therefore, flexible ducting will catch more dust and also deteriorate quicker than sheet metal ducting resulting in having your air ducts cleaned by a professional more often.

Fiberboard Ducting

Fiberboard ducting is made from fiberglass and looks like styrofoam and is probably the least common type of material used in ductwork design. If you have this type of ducting in your home, then it is probably best to have it replaced rather than cleaned. When the fiberboard is not cleaned properly, the fiberglass will become airborne and cause a lot of health hazards in your home.

Furnace Placement

The placement of your furnace in your home can present homeowners with additional dust issues. Your furnace should be located in a clean and dry space in your home. Some homes have furnaces located in crawl spaces and attics. When your furnace is located in these types of spaces, then sometimes the area around your furnace is not the cleanest environment. 

Therefore, when your furnace is not in an ideal spot, it can pull in outdoor elements such as pollen, dust, mold spores and other external pollutants into your system. If your furnace is located in a crawl space or attic, make sure the area is encapsulated from the outdoor elements so you don’t need to have your ducts cleaned more often.

Your Homes Air Tightness

As homes age they become less and less air tight. When your home starts to lose its airtightness, then you will experience higher heating and cooling utility bills and outdoor pollutants entering your home through various openings. This will result in more dust, pollen and allergens being sucked into your HVAC system. 

Your house will lose its air tightness due to gaps and cracks in the foundation, rotted siding, expansion and contraction of door seals, and worn out windows. It is always a good idea to inspect the exterior of your home each season and plug any gaps and cracks that may be leaking air. This will not only help minimize heating and cooling losses and dust entering your ductwork but also it will keep rodents and insects out.

House with a lot of clutter collecting dust.

Living Conditions

The cold hard truth is that your ducts get really dirty based on your living conditions. It is not always easy to explain this to a homeowner, but it is one of the biggest contributing factors in how often you need your air ducts cleaned.

Lots of Clutter

Some home owners love to collect objects over the years and they start to seep out into living spaces. When the clutter starts to pile up, then dust settles on these objects and it starts to not only affect your indoor air quality but it also starts to seep into your ductwork. To help mitigate dust issues, it’s time to start minimizing the clutter.

Frequency in Which You Clean

Cleaning your home on a consistent schedule will help eliminate the dust and debris in your home. This will improve air quality and keep the pollutants from entering your HVAC system. This means weakly dusting, vacuuming and mopping to get the dust under control.

Carpets & Upholstery

Carpets and upholstery are the biggest contributors to dust issues that result in more frequent air duct cleanings. Essentially your carpets and furniture act as one large filter that collects dust. When you walk on carpets and sit on your furniture the dust and debris becomes airborne and then gets sucked into your ductwork. 

By having your carpets, furniture and upholstery professionally cleaned each year, you will really notice a difference in the air quality and the cleanliness of your ducts.

Child using inhaler because of dust issues.

Health of Family Members

The health of your family members will have an impact on how often you have your air ducts professionally cleaned. Family members with severe allergies or asthma may find that having your vents cleaned every couple years will help alleviate some of your respiratory issues. 

Nearly 20 million Americans suffer from some sort of allergies related to dust mites. Dust mites love to make your air ducts their home and when the HVAC system fan turns on, they are displaced and spread throughout the residence.

Mold spores are another concern for your family’s health. Typically, when you are located in warm and damp climates, mold is more of an issue in your air ducts. The condensation that is created by your air conditioning system is the main culprit. Anytime you have condensation and high humidity, then there is a real possibility of mold forming in your air ducts. 

If you suspect you have mold in your air ducts bring in mold remediation professionals to test for it before hiring a duct cleaning service. Make sure mold remediators are state certified and not a scammer on Facebook. More harm can be done to your family’s health if the proper precautions are not taken.

Reasons to Have Your Air Ducts Cleaned Sooner Than 3-5 Years

Choosing the right time to clean your ducts depends on multiple factors. However, you may need to get them cleaned much sooner if you have a rodent infestation, excessive amounts of dust around the home or you recently bought a home from tobacco smokers. It is a strong recommendation to get a professional air duct cleaning by a NADCA certified company if any of the following issues affect you and your family.

Mouse droppings in ductwork.

Rodent Infestation and/or Insects

A rodent infestation in your ductwork calls for immediate attention. Rodents and insects carry many diseases that can affect the air quality in your home and contribute to respiratory illnesses such as Hantavirus Pulmonary Syndrome (HPS).This severe lung disease is carried by mice and is left in your ducting when they live in your home. When the furnace fan kicks on, the virus becomes airborne and it is spread throughout your home. 

If you suspect you have dead animals or rodents living inside your home, get your ductwork inspected and have it cleaned immediately. Before you hire a duct cleaning company, be sure to hire a pest control company to seal any points of entry and remove the animals. Otherwise you will be throwing away your money.

Walls covered in yellow nicotine and tar stains causing a horrible smell.

Home Previously Owned by Smokers

If you ever walked into a smoker’s home, you probably noticed a foul smell throughout the home. What you may not understand is that the nicotine and tars from tobacco products accumulate on everything it touches. Nicotine and tar are circulated through the furnace and it builds up inside the ducting. If you purchase a home and you cannot get the smell out, the odor is more than likely trapped inside the HVAC system. 

A good ducting cleaning company can help you mitigate the smell by cleaning the air ducts and sanitizing them. If the smell still lingers, you may want to consider discharging a smoke bomb and vacating the home for a day.

How Often Do I Need To Have My Air Ducts Cleaned? Clean Them As Needed!

By this point, if you have read the entire article, you will understand that air duct cleaning frequency is not a one size shoe fits all type service. Determining how often to clean your air ducts depends on various factors such as the age of your home, the condition of your ductwork, living conditions and family health.

It is up to you to decide what is best for your family in determining how often to have your air ducts cleaned. The industry standard is to have them cleaned every 3-5 years is more of a guideline and you should consider all the factors mentioned in this article before hiring an air duct cleaning company.

This can be confusing for some homeowners, so call a certified duct cleaner in your area and have them perform an inspection. Having your ducts inspected is the best way to determine when and how often you should have your furnace system cleaned.