Very low moisture cleaning (VLM for short) is an increasingly popular method of carpet cleaning used mostly in commercial environments, and less often in residential applications (though this is quickly changing). VLM is broadly defined in the industry as a method of carpet cleaning that limits drying to 1-2 hours. VLM processes include encapsulation cleaning, ‘pad capping’, bonnet cleaning and compound cleaning. In recent years the industry has seen a dramatic rise in the use of VLM, though many cleaners remain unaware of it or know little about it. This article will cover variations of the method along with the common accessories and machines used in VLM cleaning.

Bonnet cleaning is the oldest form of VLM and considered by a large part of the industry to be the most dated. In this case bonnet ‘shampoo’ (non encapsulation based cleaner, not to be confused with popular soap free products) is applied via pump or electric sprayer and cleaned using a 175 rotary machine with looped cotton bonnets. This is not much different from other VLM methods. However, because of its non encap properties, many bonnet cleaning solutions are known to cause re-soiling and residue issues. Despite overall improvements in VLM, the bonnet process lends itself to the refrain that VLM is an auxiliary or maintenance cleaning method, not a stand alone method. Bonnet cleaning is most commonly, though not exclusively, used by janitorial staffs, cleaning common areas and with high frequency.

Encapsulation cleaning (‘encap’ for short) is the most established form of VLM. The process has been in use since the 90’s and relies on encapsulation chemicals that surround and capture dirt, as opposed to “wet” cleaning that uses detergents and the natural solvent properties of water to loosen the dirt. With encapsulation the cleaning solution is delivered via an onboard shower feed or sprayer, and depending on the machine used, fiber pads or brushes will then start scrubbing the floor immediately after the application. The scrubbing itself cleans the carpet to a degree that is noticeable to the eye. The cleaning solution is then allowed to dry, after which the remaining dirt, now “encapsulated”, is removed with simple vacuuming. Encap is generally considered the most efficient type of VLM cleaning in commercial settings due to its simple process and quick 30 – 90 minute dry times.

Pad capping is similar to encapping in that it uses the same encapsulation cleaning solution. Where they differ is in physical application: the pad capping method uses different types of pads, spray systems and dwell time (though the latter is debatable). Like encap, pad capping is administered with either a 175 rotary or an oscillation pad (OP) machine, whereas encap uses these two methods plus the planetary machine (manufactured by Cimex) and counter rotating brush (CRB) machine. Another major difference is that the pads used in the pad capping method remove far more dirt during the initial scrubbing pass over the carpet, whereas the fiber pads and brushes used with encapping don’t remove as much soil initially. However, with both methods any remaining encapsulated soil is removed by a final vacuuming. Pad capping is used frequently in commercial and is the most used VLM process for residential.

Dry Compound cleaning is yet another VLM method that, like encap and pad cap, is increasing in popularity. This method relies primarily on dry compound ‘sponges’ (though encapsulation products may sometimes be used as a pre-conditioner to the compound). This compound, which is almost entirely biodegradable, is spread evenly over the carpet. The compound then draws dirt and grime from the fibers to the sponge. Counter rotating brush (CRB) machines agitate the compound into the carpet helping to further extract soil from fibers. The finishing step is a post vacuum to remove the compound. Dry times are rapid and the process is simple. While this method was primarily developed for commercial use, it has since found wide acceptance as an alternative to HWE and the “go-to” choice for ‘green’ cleaners and residential consumers alike.

Even as the popularity of VLM continues to grow among cleaners, many continue to resist it. There are many reasons for this, but the most common are its associations with dated bonnet methods, the myth of ‘sticky residue’ and the notion that a carpet is “never truly clean”. On the contrary, when applied properly, low moisture leaves carpet free of residue without wicking and, well, clean. But certain steps must be taken, the most important of which is a quality pre-vacuum. As with HWE, vacuuming removes debris as it loosens and lifts fibers, and this in turn allows the cleaning solutions to be most effective in attacking dirt and grime. And while vacuuming may be an elective step with some HWE cleaners, it is an essential for VLM to be effective. Neglecting this step will lead inevitably to lackluster results. Finally, for VLM to be most effective, you will need solid knowledge on a variety of pads and detergents, as well as when and how to use them.

Are you ready to give VLM a “whirl”? If so, it’s easier than you think. Almost every cleaner owns (or should own) a 175 machine and vacuum cleaner, so the most expensive components are not a factor. All you’ll need to purchase after that is a gallon of encapsulation cleaner, a few pads, a pump sprayer and the desire to learn something new. That’s all!

Vacuum, spray, pad and done! It’s that simple (almost always at least!). Welcome to VLM!