Case Study: Colossal Dryer Vent Clog

Updated by Lisa A on January 20, 2019 in

Dryer Vent Cleaning, Commercial Dryer Vent Cleaning

Dryer vent clogs present a real fire hazard, but even if this potential disaster does not materialize, a direct and discernible result of dryer lint buildup is a clothes dryer that doesn't do what it was meant to do, meaning frustration and headache for the resident or homeowner affected. In addition to the obvious energy-inefficiency of a dryer that runs and runs without actually drying, the homeowner or property manager is left frustrated trying to figure out the cause and often hires a repair company only to find that in fact the solution was dryer vent cleaning.

dryer vent clog


The problem

Our commercial project manager was summoned to a property in Minneapolis to provide a bid for cleaning 500 dryer vents for a multi-story apartment complex. New property management had taken over, and the residents were complaining that the clothes dryers had not been working properly for years. It had been understood that the dryer vents were being cleaned regularly, on a 2-year basis, so there was some confusion as to why the dryers were not doing their job. After some digging by a persistent property manager, it was discovered that leaf blowers fired up from down below had been called into service for the task—a task for which they are not designed and at which they fail miserably.

rooftop dryer vent cleaning


The diagnosis

At this property, multiple dryer vents from the stories below enter into one of several stacks leading to the roof. On the roof, covering each of these stacks, is a metal crown—similar to what you'd find covering a fireplace chimney. On the face of each stack was a louvered vent cover with a screen behind it. Each of these screens was covered in lint, choking off air flow. 

commercial dryer duct cleaning

Removal of this vent cover allowed access to the nine vents inside, which included not only dryer vents but also bathroom exhaust-fan vents. Interestingly, on disassembly, our technician noted evidence that there had been no previous disassembly nor access cut through the metal crown. This meant that the vents in this decades-old building had never been properly cleaned: from the top down.

The consequence? A massive buildup of lint five inches thick that prevented the proper exit of exhaust from not only the dryers but the bathroom vents as well. It was for this reason the dryers were not working well, triggering the residents' complaints. There were also several disconnects in the dryer vent line found in the attic—disconnects that likely were due to the age of the system but also as a result of previous attempts at cleaning with a leaf blower.

 clogged dryer vents


The solution

After manually removing and disposing of the 5-inch-thick lint colossus covering each collection of vent openings, the technician set about cleaning each of the dryer vent lines. To prevent the lint from one vent falling into the others while it was cleaned, he fashioned a metal plate with a hole similar in size to the vent opening, and positioned it in such a way that only the vent being cleaned was uncovered.

From this point the cleaning process is fairly standard. The technician inserts a spinning, reverse-blowing skipper ball, attached to 50 feet of air hose, all the way down the vent line through to the back of each dryer. Once engaged, the tool is pulled up the vent line and pushed down again repeatedly, while its reverse-blowing air nozzles blast lint out the vent opening. The technician knows he is done when no more lint is being expelled by the tool, and good air flow is observed from the vent. Each of the louvered vent covers and screens are cleaned with high-pressured air triggers until they are completely free from lint.


clogged rooftop dryer vent


The lesson

Dryer lint is a messy nuisance and a hazard. Its feathery lightness makes it easily propelled on a gust of warm air, as that produced by the dryer. It travels until air flow is insufficient to propel it further or until it encounters resistance, in the form of a screen over the vent opening, a corrugation or bolt in the vent line, or a sticky collection of other lint. As with a snowball rolled across the ground, the lint particles stick to each other, increasing the mass of the whole. As more lint is added, the clog grows denser and harder and eventually chokes off air flow.

Regular and thorough vent line cleaning, with the proper tools and performed by an experienced technician, is necessary to stop this process; any lint left behind will act as a magnet for other lint. Aim for a minimum of every two years, yearly if you do lots of laundry. The $100-$150 price tag is well worth the frustration you'll save yourself from the paradox of a perpetually running dryer yet perpetually damp laundry. 

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. 


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