Low-Moisture Methods and Systems

Have you ever sat and thought about cleaning systems? Hot-water extraction is arguably the world's most recognized method of cleaning carpets, but it is not the only method.

The Institute of Inspection, Cleaning and Restoration Certification's current S100 Carpet Cleaning Standard defines five methods of cleaning carpets:

  • Absorbent Compound
  • Bonnet Cleaning
  • Dry Foam
  • Shampoo
  • Hot Water Extraction (HWE)

    As you can see, there are four methods besides HWE that the IICRC identifies for cleaning carpets. These four operate in a manner commonly referred to as low-moisture cleaning. What constitutes low-moisture cleaning? While there is some debate, for the sake of this article we will define low-moisture cleaning by the amount of moisture used in the cleaning process, not by the amount removed.

    Absorbent Compound

    This method is also called dry cleaning powder and dry absorbent media. Absorbent compound is considered the driest of all methods but, contrary to its name, it does contain moisture. The medium used can be cellulosic or polymer based. The compound is evenly distributed onto the carpet via hand sprinkling or machine application. The medium is then agitated by hand brushing or by a counter-rotating brush machine.

    The soil is suspended and absorbed by the detergent-laden compound and vacuumed up, along with the compound, after the one-to-three-hour drying process.

    This method is excellent for applications where minimal facility down time is allowed. Its quick-drying qualities also make it an excellent choice for areas that have poor ventilation. The process also minimizes the chances of drink-spill wicking. Absorbent compound can be used in both residential and commercial applications.

    Bonnet Cleaning

    Bonnet Cleaning has several sub-categories, including high-speed bonnet, normal bonnet and oscillating pad (OP). All these processes suggest the use of a bonnet or pad that is slightly damp, and the common consensus is that cotton is more absorbent.

    High-speed bonnet cleaning is achieved with a 300-rpm machine. The carpet is sprayed with a detergent, and extraction occurs via a bonnet that is attached to a drive block on the machine. The process is the same as bonnet cleaning, but occurs at a higher speed.

    In normal bonnet cleaning, the carpet is sprayed with a detergent. Extraction then occurs via a bonnet that is attached to a drive block on a 175-rpm rotary machine.

    "I say bonnet cleaning, when done properly, can be as effective as any cleaning system," Gary Heacock of Heacock's Custom Cleaning Service said. "It is not limited to commercial, or limited to residential or any specific carpet type, weave or texture. The system can be used on every carpet type, if done correctly.

    "Correctly, as I see it, is not just side to side, or forwards and back, but a combination of motions. Side to side and then go back over that area making ovals, overlapping each oval by half the bonnet's width, or forwards and back, then going over the same area making ovals, overlapping each oval by half the bonnet's width. Another way is to just do ovals, left to right, then back over that same area, making ovals in the opposite direction.

    "The oval is what makes the total job as clean as possible, cleaning each individual tuft from all sides. This also gets the soils on each tuft from the top to the bottom. That's what I call deep cleaning.

    "The finished results equal any other cleaning system when done this way. The proof is in the soils contained in the bonnets. When laundered, the dirty water coming from the washing machine is equal to the dirty water coming from any HWE cleaning machine," Heacock said.

    With an oscillating pad, the carpet is also sprayed with a detergent, and extraction also occurs via a pad, but one that is thinner than a bonnet. The machine looks similar to a floor machine, but it normally rotates once per minute and oscillates, or tamps, 1,700 times per minute. This tamping is similar to the tamping taught with spot-cleaning techniques.

    Gliders are set between the carpet and the pad. These gliders adjust the depth and aggressiveness of the cleaning. This is very effective method of cleaning and removing spots that normally wick back.

    Dry Foam

    The dry foam method normally uses a dense foam generate via a machine with a foam generator. The foam is agitated into the carpet via a rotary or cylindrical brush system. The soil-laden foam can then be extracted via an onboard wet vacuum, pads bonnets or other extraction devices but is most common extracted into the same machine. Employed by thousands of commercial facilities it can aggressively clean thousands of square feet per hour, and can dry in one to two hours.


    The shampoo method includes traditional shampoos and newer encapsulation products. Encapsulation products may indeed need a separate classification. They verge somewhere between dry foam and shampoo, but have much shorter drying times.

    The product may be sprayed or applied via a shampoo tank. The equipment used runs the gamut of hand brushing with a carpet grooming brush to counter-rotating brush machines, rotary machines and three-head rotary machines. The key is the agitation. The product will break the oil bond holding the soil to the carpet and "shrink-wrap" the soils into a crystal, like a package waiting to be vacuumed away after drying.

    Rick Gelinas, president of Excellent Supply, describes encapsulation this way: "With crystallizing polymer technology, non-sticky residue can't attract other soil and can be extracted with post-vacuuming. It eliminates wicking and recurring spills, and carpets stay cleaner longer."

    With shampoo, the cleaner is distributed via a floor machine with a solution tank. The shampoo is fed to a brush that scrubs the shampoo into the carpet. The soil-laden shampoo is then extracted usually using a wet/dry vacuum or a dry vacuuming process. This is very aggressive process and can solve deeply imbedded soiling conditions. It is the wettest of all low moisture processes and has the longest drying time.

    As you can see, there are several methods and systems. A good rule of thumb is to become an expert in them all, then adapt your cleaning to the method or combination of methods that creates the best results at the least expense to you!
  • Did you enjoy this article? Click here to subscribe to i Cleaning Specialist Magazine.

    You must login or register in order to post a comment.



    Image Galleries

    The 2014 Experience Conference and Exhibition

    A look in photos at the 2014 Experience Conference and Exhibition, which was held from April 24-26 at the Embassy Suites Convention Center and Spa in Frisco, Texas.


    Yes, it's only February now - several weeks or months before the thaw depending on where you live - and hopefully this winter has been a profitable one for your business during the historical slow season. But now's also the time to start planning for the busy season - spring - so that you can hit the ground running. In this episode of The Hitman Advertising Show, John Braun shares tips and tricks on how to make this spring your most profitable yet.
    More Podcasts

    ICS Cleaning Specialist Magazine


    2015 March

    The March ICS issue features content on cleaning services, green chemistry, encapsulation, terrazzo floors, educating clients and new products.

    Table Of Contents Subscribe

    Janitorial Work

    In addition to residential and commercial carpet cleaning, do you do any janitorial work on the side?
    View Results Poll Archive


    The Carpet Cleaner's Book of Unlimited Success! (ebook)

    Don’t worry about the recession or about your competition.  Now you can be the owner of over 400 ways for carpet cleaning professionals to make more money and get more jobs!

    More Products


    Director_Buyer.jpgThe premier resource and reference guide for the cleaning and restoration industries.

    Click here to view


    facebook_40.png twitter_40px.png youtube_40px.png


    Truckmount.jpgEquipment listings and specifications from the leading industry manufacturers.

    Click here to view