Dryer Vent cleaning on commercial buildings

Had a resident manager approach me about cleaning his dryer vents. It’s a 12 story, 44 unit buildings built in 1968.

I’m going to do 1 of two things. Clean the ducts myself if the equipment is affordable and the job isn’t something that I can do with out much prior knowledge or sub it out. I know this is a VERY important service and if there were any chance that I would not be able to perform at or above regular industry standards from the get go, i wouldn’t consider it… but it appears to be a very simple job that just requires the right equipment.

I’ve checked forums and seems like most is about residential stuff, nothing like 12 story building.

If you can help out please share experience, equipment, learning curve pm or leave post. Im interested to learn about this add-on

i do a good amount of dryer vent cleaning. we use the lint eater from gardus. works very well but u need to buy extra poles for it. they have the system at lowes . Never done a large building like that . It i pretty easy to learn you
will be a pro after cleaning 2 or 3. we charge $69 to $79 each takes 20-30 minutes to do. good luck.

Are there any licensing requirements?

Does one need to discuss with there GL insurance agent to ensure coverage?

Not sure… i’m trying to fin all that out. I’ll keep researching and report what i get

Introduction: Cleaning dryer vents can be a very lucrative business. I perform on average 8 per week at $115 each, spending 45 minutes on each one which includes a 15 minute drive time per job. In this geographical area most vents are accessed from the roof top and some from ground level. I have set up all my clients on an automatic call schedule when their vent is due for another cleaning. There is an initial small capital investment, but after that it is basically a job that requires very little materials. I will outline below my procedures for determining if a vent is plugged, its flow, fire hazard, how to clean and how to determine a cleaning frequency. I have been doing this since 1999 and would perform this type work all day over appliance repair work due to low material/parts usage, ease of complexity and satisfied customers!

Pricing: I charge between $115-$140 per cleaning, depending on accessibility, normal vents get charged at $115, 2 story vents where the vent runs between the first and second story is $125 and vents we have to access in attics or hard to access vents is $140… Most are done for $115.

Determining a blocked vent: When I get to the home I scope out where the vent is located, then I perform a “safety check” on the dryer first. This checks air flow, hi temps (fire hazard, properly operating thermostats and condition of dryer (unusual noises, poor installation, etc.) To perform this test I use fluke 16 Multi Meter plus a K type thermocouple (high speed) for around $150. Place multimeter probe K-Type thermocouple in the drum.

Run the dryer on high heat, be sure to check behind the dryer for a smashed hose or a plastic vinyl hose beforehand. If the vent is 100% plugged, the hi-limit t-stat will trip and temp will NOT go up very high, usually below 170d. If the vent is 75% plugged, the temp will climb fast and go well over 240d. Anything over 240d is considered a fire hazard. If it gets to 260d, I will switch dryer to air fluff to cool it down. Another measurement I check is once the heater is off after reaching temp, I check “how fast” the temp drops per second (this is why I use a K-Type t-couple). A good working vent for an electric dryer is 2-3d drop per second or for gas 3-5d per second drop. Most plugged vents will drop 1 degree or less per second for electric or 2 degree per second for gas dryers. Once I clean the vent, I make this test again. The test takes less than 2 minutes and has been 98% accurate for me to determine when a vent is plugged.

Initial preparation: If you determine your vent is plugged or needs cleaning, give the client a quote then follow the procedure here: For roof top vents drill out the rivets of the roof cap. Drill out only enough rivets to access the vent with your equipment – I always use zinc plated screws to resecure the vent, this allows easy access next time. I put the dryer on AIR FLUFF to help expel the loosened lint I have dislodged.

Important notes here: Some lint bypasses all dryer lint filters. The lint is of course wet and likes to stick. In a vertical vent system, there is back pressure in the 4” diameter pipe which carries most lint up and outside of the home. BUT some of the wet lint sticks to the sidewalls of the galvanized sheet metal pipe and during the night when the dryer is offline, the lint dries into a substance like Paper Mache. Over a period or 1-5 yrs this buildup significantly reduces air flow. This is why a Leaf blower of a soft bristle type brush only remove loose lint, not the buildup.

Most vents you can run the 4" – 6” stainless steel brush in But if its really clogged you may need to run the clog buster. Some vents are tighter in diameter and I will use the 4" nylon brush at first then switch to a 4” diameter SS brush. Some vents are full of water, mud, birds nest, mechanical items such as screen mesh or check valves which adds to your repair. I use a Dewalt 14.4 V ½” keyless chuck to perform the work. A list below of all tools needed is listed.

Cleaning procedure: I will go in 3 ft at a time, pulling the brush out each time to allow the lint to escape. Eventually after 8-12 ft you do not need to pull the rods completely out. You will set your drill clutch at about 12-15 for the type drill I listed. This is to keep you from twisting/bending the rods if you get a jam. I wear a dust mask with a single outlet valve, due to the lint getting into your lungs for several hours. Once I hit bottom or go into flex hose you stop going in (you can hear this really loud), you will learn how to determine this in time, I pull everything out and reinstall roof cap with zinc plated sheet metal screws to make next cleaning an easier access. I then go into the house and run another vent blockage check to ensure I cleaned it. At this point you may offer to replace the plastic vinyl hose for more money and explain it is a fire hazard or give a quote to disassemble dryer cabinet and vacuum the inside. Look at washer too and see if it needs new fill hoses or the drain hose secured, rerouted.

Now for Concrete/Foundation vents that use PVC instead of galvanized sheet metal. PVC for venting is very poor for venting. We have the most blocked issues with these and this is for 3 reasons: 1) It is electrostatic. When air is pushed though this vent is makes for high static which collects lint easier. 2) It is rated at 140 degrees. Dryers run at 200+ and this softens the PVC for at least the first 5 foot of venting making lint stick much more quickly! This is where we find the majority of blockage. 3) It is usually run horizontally which is the worse run you can do. In the vertical metal vent there is back pressure that carries most of the wet lint up and out. In a horizontal vent, the back pressure is not capable of carrying the wet lint to the outside and the horizontal portion fills up quickly with lint. The stainless steel brush works the best here, lots of Paper Mache type buildup.

CAUTIONS: Some problems you will run into are flexible hoses used in walls, under houses or in attics. This is against building codes here and our vent cleaning system will rip this vent to shreds!! This vent cleaning equipment cannot be used for this type venting and we have the client sign our work order that this type venting in walls, attics under houses is a fire hazard and give them the name of a contractor that runs a vent by local code. Another problem is poorly install sheet metal vents. I just lost $500 on a 2 story vent, the builder runs the vent between the 2 floors (normal application), but he did not use any foil tape on the joints and the 4" sheet metal piping came apart in the ceiling when I was cleaning it and no access to vent! I had to pay a contractor $500 to rip out the ceiling and attach the venting properly. This is the first time this has happened to me where I could not fix it, it happens in the attic occasionally but you can go into the attic and reattach it, but these problems are rare. I now have client sign my work order on 2 story vents that I am not responsible for improperly installed vents.

NOTE: Bird’s nest, screen mesh over the vent which is against building codes and check valves should be removed before you clean vent. These are all fire hazards anyway.

Frequency: Most newly installed vents can go 4 yrs between cleanings for a family of 4. A PVC vent we recommend every 1-3 yrs and commercial every year. The frequencies are determined upon how many in house hold using laundry, style and construction of vent. We review each vent, recommend a periodic cleaning schedule, input this into our database and wait for an automatic reminder to tell us its time! What a great tool/money maker.

Equipment Needed: I use the following equipment:

  1. Suitable ladder
  2. Heavy duty cordless drill
  3. Vent cleaning rods/brushes
  4. Safety equipment
  5. My ladder I purchased from Home Depot at this link.  It fits inside a small vehicle easily.


P/N from internet 168443, Catalogue# 100325240, SKU# 537238.

  1. Cordless drill from Johnstone Supply , 14.4V Mfg# DC983KA, I suggest buying 1 hr vehicle charger DW9109.
  2. Vent Cleaning system, Pro-Spin, ph#  800-994-7933, [pro spin](http://www.pro-spin.com), system is expensive but the best, in my opinion, and removes 100% of the lint buildup in the pipe. A Lot of the nylon type brush systems or leaf blowers will not remove this buildup, only the loose stuff.  I use 6ft and 4ft rods, the 6ft rods are great for just starting and then add 4ft as the length gets over 18ft. I carry 40 foot of rods for commercial cleanings.
  3. Safety Equipment, I use a left hand leather glove to hold the rods while they are spinning, glasses and a breathing mask. Good shoes are key for getting traction on roof tops.

A Dryer uses on average 23 100 watt light bulbs of power. With a proper vent cleaning, you can tell you client they can pay for the vent cleaning in 3 months on energy saved, wear and tear on dryer and knowing their fire hazard is gone!

I am happy to answer questions on this, alphaomega@hughes.net

Mike Maloney

Alpha Omega Appliance Service


Thanks, Joe.

That’s good stuff Joe. I’ve a few with a drill and brushes. But never really educated myself to make it a sustainable add on. Thanks for posting that.

If you want more info on this subject please PM me and I will send you a link.

Great post - an easier way we use is with a digital anemometer ($20 ebay)

  1. Start up the dryer
  2. Locate vent on outside, remove Louvre’s and take reading - it should be a minimum of 8 meters per second
  3. Dryer off run rods through
  4. After cleaning up start dryer and see if there is an improvement which is always so

We also offer dryer cleaning which came from not being happy leaving lint inside the dryer, especially with the amount of lint in some dryer vents. The truth of the matter is a fire will not start in the dryer vent, but inside the dryer!

Here is a video recently taken showing the clogged dryer just after we unclogged it then inside a 15 month old dryer


Nice informative post. I love your post. Dryer vent cleaning is very important for Dryer it prevent the dryer fire.