What is the Best Method for Carpet Cleaning?
The quick answer is The Hot Water Extraction Method, otherwise known as Steam Cleaning. That is, as long as the carpet cleaner’s equipment is of good quality and in good condition. If you’d like to read further, there are essentially 5 different methods of carpet cleaning to choose from. Some methods are more effective than others and not all are right for your type of carpet. Read further to learn more about the details of each method.
Carpet Shampooing was the primary method of cleaning residential carpets up until the 1970’s. Some people still refer to other more advanced methods as “shampooing” when in reality, the shampooing method is far outdated. Carpet shampooing has no effective way of removing all the water and soap that was applied, leaving the carpet full of sticky soap that will attract more dirt over time and leaving the customer with carpet that can take days to dry. (Mold can start to grow if carpet is not dried within 24 hours!) My advice as a professional carpet cleaner is to stay far away from carpet shampooing.
The Bonnet Cleaning method starts by misting the carpet with a cleaning agent then using a large circular pad on a floor machine that spins at about 175 rpm. As the bonnet rotates, soil is transferred from the carpet into the bonnet. The big advantage to bonnet cleaning is that the carpet will dry very quickly, usually within an hour. The downside is that this method tends to be only a surface cleaning, improving the appearance of the carpet but not doing much for removing heavily imbedded soils, bacteria, or allergens. It tends to push much of the soil downwards making the carpet re-soil to the surface in a relatively short time. Sticky chemicals will remain, increasing the likelihood of rapid re-soiling. Also, this method creates a lot of friction as the bonnet rotates on the carpet. This is the method that ChemDry used until carpet manufacturers determined that bonnet cleaning on residential carpet will void warranties due to pile distortions. (ChemDry has since switched to the Hot Water Extraction Method.) This method is recommended for commercial use only as commercial carpets can withstand the high friction generated by a heavy machine rotating a large fiber pad for any period of time.
The Foam Encapsulation Method relies on the chemistry of polymers encapsulating (crystalizing as it dries) around dirt, allowing the dirt to be more effectively dry-vacuumed from the carpet than they would without the polymers. These polymers will also encapsulate around the carpet fibers, helping to extend the time before re-soiling occurs. The advantage with this method is it allows for extremely fast dry times, usually within half an hour. The downside is that this in not a deep-down thorough carpet cleaning since much of the encapsulation will remain in the carpet. Dry vacuum cleaners are capable of only pulling out a fraction of the encapsulated dirt. Another disadvantage is that there is no high heat involved that will sanitize your carpets. This method is only recommended as a cheap alternative when the recommended method of hot water extraction is not a viable alternative.
Dry Carpet Cleaning
With the Dry Carpet Cleaning Method, a dry compound (slightly moist) is spread over the entire carpet. A motorized counter-rotating machine with a spinning brush is used to open up the carpet fibers, allowing the compound to settle within those fibers. The compound acts like a sponge, absorbing the dirt. Once dry, the compound and dirt are then vacuumed with a standard vacuum cleaner or as part of the counter rotating machine used to disperse the chemicals. This method is good for commercial use since dry times are extremely fast (less than 30 minutes) and the machine that is used does not require running hoses that can’t reach hundreds of feet, required to reach into some office buildings. The downside is much like the encapsulation method. Residues are left behind because there is no flushing of the dirt and chemicals. Some with chemical sensitivities complain of problems from the remaining chemicals and there is no sanitization of the carpet from high heat water. This method is recommended as a periodic maintenance in between a more thorough carpet cleaning.
Hot Water Extraction
The Hot Water Extraction Method (otherwise known as Steam Cleaning) in done by the use of either a portable machine or a large truck-mounted system. First, a prespray is spayed over the entire carpet in order to loosen up the dirt. The longer dirt is on any surface, the more it adheres to that surface. Once the chemical dwells for a few minutes, it is then ready for extraction. Hot water comes from the machine and is sprayed into the carpet fibers. This sprayed water (along with the cleaning agent and dirt) are immediately extracted back out and into the cleaning machine. Out of the five methods, this is the most thorough as it is a total flushing and rinsing of all the carpet fibers all the way down to the backing of the carpet. The downside to this method only comes when a very weak portable or an unmaintained truck mount is used because of the potential of not having enough water extracted. This was often the case years ago when this process was in its infancy. Now, in our modern era, it hardly occurs. Carpets usually dry in hours, not days. The more advanced truck mounts have very high heat so that carpets are sanitized with every cleaning. Dirt, allergens, dust mites, bacteria, etc.… all are extracted up and out of the carpet fibers. As long as a modern truck-mount is used, the hot water extraction method is by far the most thorough and effective way to clean carpets.