The above photo was taken at an apartment building in Chaska before the dryer vent was cleaned. It can be assumed that when lint is hanging off of the outside vent (and had to travel a good distance to get there) that there is a buildup of lint inside the vent line and cleaning is needed. Of course, a dirty dryer vent line will not always result in lint hanging from or stuck to the outside vent, so it should never be assumed that if lint is not visible on the outside, it is not present on the inside.
 
What is the difference between residential and commercial dryer vent cleaning? 

Typically, in a commercial setting—that is, in multi-unit dwellings--the dryer is located more toward the interior of the building and not as close to a wall, through which the vent will finally exhaust. This means that in most cases, the run is longer—sometimes 35 to 50 feet in length--than in a single-family home, and it also contains more twists and turns than those that vent in a straight shot through the wall to the outside. In many cases, dryers in multi-unit dwellings vent onto the roof. All of this means that the process for cleaning the vent line is more complex and the need more frequent than in a residential setting.

How are commercial dryer vents cleaned?

In apartment buildings and condominiums, it is rare that any dryer vent lines are shared; typically each unit has its own dryer and dryer vent line, which exhausts somewhere out the side or roof of the building. In some cases, the first and subsequent floors vent out the side of the building, and the top floor vents to the roof. In other cases all dryers vent to the roof.

Regardless, the process for cleaning them is similar. The technician positions himself where the dryer exhausts (using a lift to reach the higher floors). He inserts a cleaning tool attached to a high-pressured air line into the vent and feeds it down the vent line, as far as it goes, until it reaches the back of the machine itself. When the tool (a reverse-blowing spinning air ball") is engaged, it spins around and spits out air through tiny holes in the metal ball. As the technician slowly extracts the tool, the lint is blown out with it (quite forcefully; most technicians wear face masks). The technician repeats the process if necessary until he has confirmed good air flow from the vent.  Importantly, the technician will also remove any screening that is in place over the dryer vent, as this is a violation of code and additionally a fire hazard. 

How often should commercial dryer vents be cleaned?

Typically dryer vents in multi-unit dwellings such as apartments and condominiums should be cleaned yearly. Most properties of this nature have an ongoing yearly contract for service with an HVAC cleaning company.

Estimates can be provided for the cost to clean all vents in a building in a single service, and prices vary depending on how many units to be cleaned, how many stories in the building, how long the dryer vent lines run, and where the dryers exhaust. Obviously, the more units, the higher the total price (though the cost per unit tends to decline as the number of units increases). Higher floors would necessitate the rental of a lift, which would also contribute to the estimate total. 

Reputable commercial dryer vent cleaners are equipped and experienced to handle properties of all sizes and configurations, and yearly contracts establish consistency and predictability with the project, making planning easier on property management companies—and dryers safer and more efficient for tenants. 

Wanna dig deeper? Our commercial dryer vent cleaning page contains detailed descriptions, before and after photos, and videos of our commercial dryer vent cleaning processes.

View Commercial Dryer Vent Cleaning Page

Many thanks to our commercial project manager Ben S for lending his expertise to this article. ​

The air handling unit (AHU), or rooftop unit (RTU) if it's located on the roof, is the heart of a commercial HVAC system. Most commercial cleaning jobs include cleaning both the AHUs/RTUs and their associated ductwork. When estimating these jobs, the commercial project estimator will consider the unit's location and how difficult it is to access (e.g., a hanging AHU), its size, the labor involved in removing the access panels, and of course, how dirty the unit is. ​

Preparation for AHU/RTU cleaning

Before cleaning can take place, lockout/tagout procedures must be implemented in order to ensure a safe work environment.  If there are smoke sensors in the ducts, the system should be put into test mode for the duration of the work. All access panels to the unit are opened, and air filters removed. In order to protect electrical components and the supply and return drops, 2- or 4-mil polyethylene sheeting is placed. 

The cleaning process

Cleaning of the unit begins with a HEPA-filtered dry vacuum. All interior-insulated surfaces are vacuumed in order to remove larger debris. The commercial technician will then apply degreaser to the fan and other metal components inside the unit to remove grease that's been previously applied and has built up over time. A pressure-washer is then taken to the unit, and, if necessary, a scrubbing pad for hard-to-remove debris. 

To clean the unit's heating and cooling coils, a coil cleaner is applied with a sprayer and allowed to sit a few minutes until foaming. Once the foam has worked its magic, the technician uses a pressure-washer to rinse it off at a downward angle, toward the drain pan. The drain pan itself is then cleaned with a pressure washer and wet-vacuum. 

One of the final steps in the process is to ensure that the drain line is properly draining, as overflow from the drain line would fill the drain pan and enter the supply duct line, potentially contributing to mold growth on the insulation. 

When the cleaning is complete, all excess water is wet-vacuumed and dry rags are used to wipe metal surfaces if needed. The unit is then reassembled and all access panels replaced. 

The benefits of air handling unit cleaning

Your building's occupants and your HVAC system will thank you. Cleaning of the air handling unit and its associated ductwork means the minimization of contaminants entering the indoor air, Increased efficiency of the overall HVAC system due to improved air flow, increased ability of the unit to heat and cool occupied spaces, and prolonging the life of the unit. 

Wanna dig deeper? Our commercial air duct cleaning page contains detailed descriptions, before and after photos, and videos of our commercial duct cleaning processes.
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View Commercial Duct Cleaning Page

Many thanks to our commercial project manager Ben S for lending his expertise to this article. 

Commercial air ducts, as in an office setting, are often lined with interior insulation for the purpose of noise attenuation and the reduction of heat transfer. Ducts with this insulation on the inside (as opposed to exterior-insulated, or having no insulation at all) are often referred to as "lined ducts." Interior insulation reduces the amount of fan and other system noises heard moving through the ducts, and additionally allows air that is heated or cooled to maintain its temperature while making its way through the ductwork. The twofold benefit is a quieter system for building occupants, and greater overall system efficiency, reducing energy costs.​

Wanna dig deeper? Our commercial air duct cleaning page contains detailed descriptions, before and after photos, and videos of our commercial duct cleaning processes.

View Commercial Duct Cleaning Page
​Many thanks to our commercial project manager Ben S for lending his expertise to this article.