To people outside of the HVAC industry (Heating, Ventilation, and Air Conditioning), the various elements that make up the HVAC system can seem murky and vague and consequently are often conflated. The term "furnace ducts" is an example of this tendency. Furnace cleaning and air duct cleaning are sometimes confused, and we often have customers request one when what they really want is the other (or both). Here's the run-down.​

What is Furnace Cleaning?

Furnace cleaning involves only the individual components of the furnace itself—like the heat exchanger, the blower motor, the combustion chamber, burners, fan, etc. These are typically cleaned with the combination of high-pressured air and an industrial vacuum. Some of the heavy-lifting furnace parts, like the evaporator coil, often require a more specialized cleaning for an additional cost.

A quality cleaning minimizes debris in the unit and improves air flow, increasing energy efficiency. It will also reduce the number of contaminants and particles entering your air ducts only to recirculate throughout the system. Furnace cleaning typically does not include cleaning of the ductwork and vents associated with the furnace.

What is Air Duct Cleaning?

Air duct cleaning is the process of removing dust, debris, and contaminants from your air ducts, including the main supply trunk and main return, as well as the branch lines. Laypeople sometimes refer to it as "vent cleaning," though this term is a little reductive: air ducts are the vast system of (usually) metal tubes that run from your furnace throughout your home, distributing heated or cooled air; vents are simply the point where the ducts open into the house. 

Duct cleaning utilizes specialized tools such as air whips, snakes, and wands to move debris through the ducts toward an industrial vacuum for removal. Typically, different tiers of service are available, depending on how dirty the ducts are and how long it's been since they were last cleaned. 

How are the two services similar?

Air duct cleaning and furnace cleaning use similar tools: high-pressured air, powerful suction, and sometimes agitators. They both contribute to energy efficiency and improved air flow (and air quality) by reducing the amount of debris and contaminants hindering the HVAC system. The two services are often performed in tandem, for the most comprehensive system cleaning. Because the air ducts and furnace form part of the same system, it is highly likely that if one is dirty, the other is too.

Which service do I need?

For reasons stated above, it is usually a good idea to have both the furnace and ducts cleaned at the same time—but this is not a hard and fast rule. If your furnace is new (a year or so), and has a properly fitted filter (this is key), it may not need a cleaning yet. However, if your furnace is dirty, it is virtually guaranteed that your air ducts are as well, since the furnace blows air directly into the supply ducts.

Regarding air duct cleaning, it is generally recommended that this be performed every two years. Ideally you would start with the highest level of service and then the "maintenance" level service will suffice for the next few cleanings. If you are unsure whether you need either service performed, you can request that the technician conduct a visual assessment and discuss with you (and show you) his findings. 

To simplify things and maintain a schedule that's easy to keep track of, it's advisable, when first taking up residence in a new home, to have both the air ducts and the furnace cleaned at the highest level so you can be sure that indoor contaminants and debris are minimized. For services thereafter, if you keep on a regular schedule, you'll pay less for the cleaning, and many companies offer a discount on multiple services, increasing the benefit of having both services performed at once.

Wanna dig deeper? Download our free tipsheet: 5 Questions to Ask Before Hiring a Furnace Cleaning Company. 

Dryer vent cleaning is the process by which lint is removed from your dryer vent line, from the machine itself all the way through to the outside vent. This lint is very combustible, and the combination of a dryer vent line clogged with lint and the sustained blast of hot air from your dryer creates an extreme fire hazard. Cleaning the vent line frequently, and thoroughly, is crucial to home fire safety.












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Recently one of our technicians went to a home in Blaine, Minnesota, to clean out the dryer vent. The wife informed our tech that the machine had not been drying clothes properly, and that her husband had tried to address the problem by taking a leaf blower to it. The dryer vent line exhausted onto the roof. Our technician climbed the roof and found that the husband's efforts had merely pushed all the debris toward the vent opening, but without enough force to expel it, thereby creating a bigger clog and causing the damper to malfunction.

What is the process for cleaning out a dryer vent with a leaf blower?

e standard DIY process for dryer vent cleaning with a leaf blower is to disconnect the clothes dryer from the wall and then insert the nozzle of a leaf blower into the air vent line where the dryer had been connected (preventing the escape of air by wrapping the area where the two connect with a towel, or a tape of some sort). The user would then start up the leaf blower, which is supposed to propel the lint down the line and out the vent to the outside. 

Why might this process not work?

In order for this method to be effective, your dryer vent line would have to meet several criteria, and most of them don't:

• It should be short in length—only a few feet long. A leaf blower can only purge a few feet of dryer vent.
• It should have no twists or turns, just a straight shot from machine to outside. The blast of air from a leaf blower is not going to turn corners very well.
• It should not be made of accordion-style flex ducting, only rigid metal. Lint tends to collect in the folds of the accordion.
• It should have an outside vent that is easily accessible, to test for air flow. The dryer vent cannot be considered clean without testing for good air flow.
• It should not have any metal screening over the outside vent (no dryer vent should!). These serve only to trap lint and prevent its exit, creating a fire hazard.
  
  

If all of these criteria are not met, you could easily compound the problem by pushing all the lint to a specific location and creating a clog. A much more effective--reliably effective--process for cleaning the vent line is to use a tool that will pull the lint out to where you can see it, rather than pushing it to where you may not be able to.


What is the proper method of dryer vent cleaning?

The most effective method of dryer vent cleaning is to insert a tool called a reverse spinning skipper ball, attached to a high-pressured air line, from the outside vent through the length of the vent line to the dryer itself. When the tool is engaged, it reverse-blasts air from its nozzles and spins. As it is pulled backward and withdrawn, away from the dryer toward the outside vent, it pulls the lint with it, expelling it with great force. This process can be repeated as many times as necessary until all lint is removed. The technician would then check the exit velocity to ensure proper air flow and to confirm the absence of any blockage.

This is the process our technician used at the home in Blaine, clearing the line completely and achieving excellent air flow. All in a day's work!

Wanna dig deeper? Download our free tipsheet: 5 Questions to Ask Before Hiring a Dryer Vent Cleaning Company.

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Many thanks to our technician Ben S for lending his expertise to this article.