When the time comes to select a professional carpet cleaner, in addition to knowing how much it will cost, you will likely want to know more about the cleaning methods they use, including the safety, effectiveness and environmental impact of each.
There are three basic carpet cleaning methods:
The Shampoo or Foam Method
This method involves a machine in which a solution is used with water in order to create a shampoo or foam that is sprayed into the carpet. It is then worked into the carpet by a machine with brushes. The shampoo or foam is said to release the soil from the fibers and allows them to be vacuumed by the suction of the machine.
The problem with this type of cleaning is that the foaming cleanser leaves behind a sticky residue, which will actually cause more dirt to stick to your carpet. This causes your carpet to look dirty sooner.
The other side of this could be using too much water in the solution and not being able to suction enough of it out of your carpet. This could create a wet soggy carpet that won't dry within 24 hours, which can be a paradise to mold and mildew, not to mention all the germs and microscopic organisms that would love to call the underneath of your carpet home.
The Dry Chemical Cleaning Method
The dry chemical cleaning method is also known as an absorbent cleaning method. Very little water is used with the dry absorbent cleaning compound. The compound is a powder treated with detergent and solvent. It is sprinkled and brushed into the carpet via a spinning bonnet and worked into the pile of the carpeting. The solution in the powder is said to release soil from the fibers and a vacuum is then used to remove the compound.
This appeals to some because their perception is that the bonnet is scrubbing their carpet, hence reasoning it will be cleaner. Many who are knowledgeable in the carpet industry would debate this. They would cite that some carpet soils such as sand have numerous cutting edges and when repeatedly forced over carpet fibers, it contributes to fraying the carpet causing irreversible damage.
Also, over the years, consumers have voiced concern about the chemicals used in the process, and the chemical residue left behind. The concern is about any health effects associated with allowing their families to play on carpet that contains chemical residue.
The Hot Water Extraction (HWE) Method
Hot water extraction is also known as steam cleaning. A pre-spray releases the soil from the fibers and breaks it down into smaller particles. High pressure is used to force the heated water into the carpet fibers, essentially flushing your carpet clean, as soil and water is removed by the vacuum system. Done properly this is the most effective method to thoroughly clean your carpets. Hot water extraction (HWE) cleaning can remove more soil than any other method.
Most professionals agree that HWE is the best way to get your carpet clean and to help it stay that way. Some portable HWE units utilize the same technology as truck-mounts. However, the truck-mounted systems are operated only by professionals and they are larger and much more powerful. These machines produce very hot water and a powerful vacuum that easily removes much more water and soil.
Carpets cleaned professionally with truck-mounted HWE systems are usually dry to the touch in a few hours and completely dry within 12-24 hours. Most carpet manufacturers recommend hot water extraction and some companies will actually void their warranty if any other method is used.